UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of May 2026

Commission File Number: 001-15092

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

(Translation of registrant’s name into English)

Turkcell Küçükyalı Plaza

Aydınevler Mahallesi, İsmet İnönü Caddesi, No:20

Küçükyalı B Blok Ofispark

34854 Maltepe
Istanbul, Türkiye

(Address of Principal Executive Offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

x Form 20-F  ¨ Form 40-F

Enclosure: A press release dated May 11, 2026 announcing the release of the registrant's first quarter 2026 results.

Contents

NOTICE

This press release contains the Company’s financial information for the period ended March 31, 2026, prepared in accordance with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (“IASB”). This press release contains the Company’s financial information prepared in accordance with International Accounting Standard 29, Financial Reporting in Hyperinflationary Economies (“IAS29”). Therefore, the financial statement information included in this press release for the periods presented is expressed in terms of the purchasing power of the Turkish Lira as of March 31, 2026. The Company restated all non-monetary items in order to reflect the impact of the inflation restatement reporting in terms of the measuring unit current as of March 31, 2026. Comparative financial information has also been restated using the general price index of the current period.

This release includes forward-looking statements within the meaning of Section 27A of the U.S. Securities Act of 1933, Section 21E of the U.S. Securities Exchange Act of 1934, and the Safe Harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. This includes, in particular, and without limitation, our targets for consolidated revenue growth, data center and cloud revenue growth, EBITDA margin, and operational capex over sales ratio for the full year 2026. In establishing such guidance and outlooks, the Company has used a certain number of assumptions regarding factors beyond its control, particularly in relation to macroeconomic indicators, such as expected inflation levels, that may not be realized or achieved. More generally, all statements other than statements of historical facts included in this press release, including, without limitation, certain statements regarding our operations, financial position, and business strategy, may constitute forward-looking statements. Forward-looking statements can generally be identified by the use of forward-looking terminology such as, among others, “will,” “expect,” “intend,” “estimate,” “believe,” “continue,” and “guidance.”

Forward-looking statements are not guarantees of future performance and involve certain risks and uncertainties that are difficult to predict. In addition, certain forward-looking statements are based upon assumptions as to future events that may not prove to be accurate. Many factors could cause the actual results, performance, or achievements of the Company to be materially different from any future results, performance, or achievements that may be expressed or implied by forward-looking statements. Should one or more of these risks or uncertainties materialize or underlying assumptions prove incorrect, actual results may vary materially from those described herein as anticipated, believed, estimated, expected, intended, planned, or projected.

These forward-looking statements are based upon a number of assumptions and other important factors that could cause our actual results, performance, or achievements to differ materially from our future results, performance, or achievements expressed or implied by such forward-looking statements. All subsequent written and oral forward-looking statements attributable to us are expressly qualified in their entirety by reference to these cautionary statements. For a discussion of certain factors that may affect the outcome of such forward- looking statements, see our Annual Report on Form 20-F for 2025 filed with the U.S. Securities and Exchange Commission, and in particular, the risk factor section therein. These forward-looking statements should not be relied upon as representing the Company’s views as of any date subsequent to the date of this press release. All forward-looking statements in this press release are based on information currently available to the Company, and we undertake no duty to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise.

The Company makes no representation as to the accuracy or completeness of the information contained in this press release, which remains subject to verification, completion, and change. No responsibility or liability is or will be accepted by the Company or any of its subsidiaries, board members, officers, employees, or agents as to or in relation to the accuracy or completeness of the information contained in this press release or any other written or oral information made available to any interested party or its advisers.

FINANCIAL HIGHLIGHTS

HIGHLIGHTS

(1) EBITDA is a non-GAAP financial measure. See page 14 for the explanation of how we calculate Adjusted EBITDA and its reconciliation to net income. 

(2) EBIT is a non-GAAP financial measure and is equal to EBITDA minus depreciation and amortization expenses. 

(3) Our net debt calculation includes financial assets at fair value, whether through other comprehensive income or through profit and loss, reported under current and non-current assets, as well as financial assets at amortized cost. Required reserves held in CBRT balances are not included in total cash and net debt calculation.

COMMENTS BY CEO, ALİ TAHA KOÇ, PhD

The first quarter of 2026 marked a historic milestone in Türkiye’s digital transformation journey. At Turkcell, we proudly introduced Türkiye to 5G in Turkcell quality, backed by our 32 years of technology leadership, strong infrastructure investments, and innovative vision. With the launch of 5G, we not only advanced communication standards but also paved the way for a next-generation digital infrastructure. This infrastructure will enhance our country’s competitiveness across many sectors, from industry to healthcare and from education to transportation. With the widest frequency bandwidth, our high-capacity network architecture, strong fiber infrastructure, and data centers, we made a strong start to this new era. Following the successful completion of our 5G preparation and tender processes, we launched a large-scale advertising campaign with a world-renowned celebrity. The strong interest in our “5-fold” campaign, launched to celebrate the 5G era, within a very short period clearly demonstrated our subscribers’ excitement for the next-generation connectivity experience. It also showed that the 5G experience we offer resonates strongly across all segments of society.

This new era, ushered in by 5G, has brought to the forefront not only our strong technological infrastructure but also our long-term investment vision and financial flexibility. While we continue to pursue investments that will shape Türkiye’s digital future with determination, our ability to access international financing sources has been a key enabler of our strategy. The USD 1 billion Murabaha syndicated loan we secured to support investments in 5G transformation and other next-generation connectivity technologies, once again confirmed global investors’ confidence in our Company’s vision and strong financial structure. Moreover, this transaction was recorded as the largest corporate Murabaha syndicated loan ever executed by a Turkish company.

We completed the first quarter with strong financial results. Our consolidated revenues reached TRY 68.4 billion, increasing by 8.9% year-on-year. Digital Business Services (DBS) and Paycell continued to outperform the Group. Consolidated EBITDA¹ increased by 3.2% to reach TRY 28.3 billion, while the EBITDA margin remained healthy at 41.4%. Our net profit increased by 14.9% to TRY 4.6 billion.

Leadership in digital transformation: 5G-enabled solutions and new speed standards

We experienced a quarter in which market dynamics rationalized compared with previous quarters. Thanks to our customer-focused approach, strong infrastructure, and innovative offerings, we closed the first quarter with positive results in Mobile Number Portability (MNP). Our total mobile subscriber base also expanded with a net addition of 655 thousand subscribers. Our postpaid subscriber base, which is at the core of our sustainable value creation strategy, maintained its steady growth with a net addition of 661 thousand, reaching a postpaid subscriber share of 81%. Supported by the increase in the postpaid subscriber share and our strong performance in upselling subscribers, mobile ARPU (excluding M2M) remained resilient. This was despite limited pricing adjustments in an intensely competitive environment of the previous year and persistently high inflation.

With Superbox 5G, we launched the era of fiber-speed internet in regions not yet covered by our fiber infrastructure, supported by ultra-powerful Wi-Fi 7 modem capability. With this momentum, our Superbox subscriber base reached 754 thousand, with a net addition of 38 thousand. In addition, with our portable “Superbox GO” modem, we began offering our customers a truly location and cable independent, flexible 5G connectivity experience.

By declaring 2026 as the “Year of Speed”, we also redefined the rules of the game on the fixed side. With our Superonline UltraFiber packages, supported by Wi-Fi 7 technology for the first time in Türkiye, we became the first and only operator to offer home internet speeds of up to 10 Gbps to our subscribers. In the first quarter of the year, we achieved a total of 36 thousand net fiber subscriber additions, including our resell portfolio, of which 21 thousand came from Turkcell fiber. In line with our fiber-focused profitable growth strategy, our DSL and cable subscriber base continued to decline. Supported by sustained demand for high-speed packages and our strong focus, the share of our fiber subscribers with speeds of 1,000 Mbps and above increased to approximately 20% of our total residential fiber subscribers. Driven by our strategy of migrating subscribers to higher-tier packages, pricing adjustments, and the contribution of our IPTV service, residential fiber ARPU grew by 9.7% year-on-year.

With our continued fixed infrastructure investments in the first quarter, we expanded our Turkcell fiber footprint by an additional 138 thousand homepasses, bringing the total to 6.5 million. Our take-up rate reached 41.8%.

Consistent growth in our strategic focus areas

Paycell, which is the main growth engine of our Techfin business, continued to grow above the Group average despite a high base effect. Paycell revenues increased by 15%, driven by strong momentum in the POS and mobile payment segments. On the other hand, Financell’s revenues declined as ongoing installment limitations constrained growth in new loan volumes. However, its Net Interest Margin (NIM) expanded significantly to 8.3%, up by 3.6 points compared with the same period last year. Total revenue growth in the Techfin segment was at 4%.

DBS made a very strong start to 2026. Rising hardware revenues, supported by increasing corporate projects, together with the 21% growth in our data center and cloud business, drove a 64% year-on-year increase in DBS revenues.

Sustainability vision reinforced by international achievements

By positioning sustainability among our strategic priorities, we carefully consider the environmental and social impact of all our business processes. We move forward with the goal of reducing our environmental footprint and increasing efficiency through our investments in this area. In line with our sustainability targets, we are increasing our capacity by investing in our own solar power plants, while also evaluating inorganic growth opportunities through strategic acquisitions. We completed the acquisition of a 12.1 MW solar power plant in Mersin in April. Following this acquisition, our total active solar energy capacity reached 74.4 MW.

Another development that boosted our motivation in our sustainability efforts was the global recognition of our environmental performance, as reflected in the “Global A” score we received under the CDP Climate Change Program.

This quarter, we also published our 2025 sustainability report in compliance with TSRS. Within the scope of the report, we addressed climate-related risks and opportunities in a holistic manner. We also expanded the scope of our environmental performance by reporting our water footprint for the first time this year. We believe that these efforts have reinforced our alignment with national regulations and global climate targets, while also strengthening our engagement with our stakeholders.

Turkcell’s signature on global platforms

We successfully represent our country and our sector on international platforms. At the Mobile World Congress (MWC 2026), the model we developed with industry stakeholders to block international fraudulent calls, which has prevented millions of fraud attempts on our network to date was selected by the GSMA as a best practice. In line with our vision of driving innovation in the sector, we also entered into strategic partnerships to carry out R&D activities on 6G and next-generation network technologies at MWC 2026.

As Türkiye’s Turkcell, I sincerely thank my dedicated colleagues who contribute to every step we take with the motivation to move our country forward, as well as our Board of Directors, shareholders, and business partners for their support.

(1) EBITDA is a non-GAAP financial measure. See page 14 for the explanation of how we calculate Adjusted EBITDA and its reconciliation to net income FINANCIAL AND OPERATIONAL REVIEW OF FULL YEAR

Financial Review of Turkcell Group

(1) Excluding depreciation and amortization expenses. 

(2) EBITDA is a non-GAAP financial measure. See page 14 for the explanation of how we calculate Adjusted EBITDA and its reconciliation to net income. 

(3) EBIT is a non-GAAP financial measure and is equal to EBITDA minus depreciation and amortization expenses.

Revenue of the Group grew by 8.9% year-on-year, reaching TRY68,377 million (TRY62,767 million) in Q126. This growth was primarily driven by the robust performance of Turkcell Türkiye, mainly attributable to corporate revenues.

In the first quarter, Turkcell Türkiye revenues, representing 90% of Group top-line, increased by 8.6% to TRY61,877 million (TRY56,957 million).

Techfin segment revenues, accounting for 5% of Group revenues, grew by 4.0% to TRY3,740 million (TRY3,594 million). The driver of this growth was Paycell business. Please refer to the Techfin section for details.

Other segment revenues, comprising 4% of Group revenues, which mostly includes Turkcell International revenues, energy business revenues and non-group call center revenues, rose 24.6% to TRY2,760 million (TRY2,215 million).

Cost of revenue (excluding depreciation and amortization) increased to 47.1% (45.0%) as a percentage of revenues for the first quarter of 2026. This was driven mainly by the increase in cost of goods sold (3.7)pp, radio expenses (0.4)pp, personnel expenses (0.3)pp, and other cost items (0.2)pp, despite the decline in funding costs (0.8)pp, energy costs (0.7)pp, treasury share (0.7)pp and interconnection costs (0.4)pp as a percentage of revenues.

Administrative expenses increased slightly to 4.4% (4.2%) as a percentage of revenues this quarter, primarily driven by personnel expenses.

Selling and marketing expenses as a percentage of revenue remained broadly stable at 6.6% (6.7%), despite higher 5G-related marketing expense. The increase in marketing expenses was offset by the slower growth in personnel expenses relative to top-line expansion.

Net impairment losses on financial and contract assets were at 0.5% (0.4%) as a percentage of revenues in Q126.

EBITDA1 increased by 3.2% year-on-year in Q126 leading to an EBITDA margin of 41.4% (43.7%).

Depreciation and amortization expenses increased by 7.1%, amounting to TRY17,861 million (TRY16,680 million).

Net finance income reached TRY1,569 million (TRY469 million cost) in Q126. This strong improvement was attributable to higher monetary gains arising from the capitalization of 5G license. Excluding monetary gains, net finance costs rose due to a higher net short FX position led by increased foreign currency liabilities linked to 5G.

See Appendix A for details of net foreign exchange gain and loss.

Net Other expenses were at TRY427 million (TRY588 million) in Q126.

Income tax expense increased to TRY7,252 million (TRY4,528 million). Please recall that inflation accounting was discontinued in the 2025 statutory financial statements, and its impact became visible in our financials starting from Q4 2025. This continued to be the main driver of the higher income tax expense in Q1 2026. In addition, only limited fixed asset revaluation was performed during the period, which provided a limited offset against the adverse tax impact. This increase in the tax expense during the quarter was primarily attributable to deferred tax expense, while the impact of cash tax payments remained limited.

Net income of the Group increased by 14.9% to TRY4,634 million (TRY4,033 million) in Q126. This improvement resulted from substantial monetary gain registered in the first quarter along with improved contribution from TOGG. Profit before income tax grew by 38.8% year on year to TRY11,887 million (TRY8,561 million), driven by strong operational performance and diciplined balance sheet management.

(1) EBITDA is a non-GAAP financial measure. See page 14 for the explanation of how we calculate adjusted EBITDA and its reconciliation to net income.

Total cash & debt: Consolidated cash as of March 31, 2026 decreased to TRY95,773 million from TRY101,048 million as of December 31, 2025. This decline was primarily attributable to the first installment of the 5G license payment, including VAT, totaling USD653 million, together with the TRY3.2 billion Wireless Usage Fee, which is paid in the first quarter of each year, as well as bonus payments to employees. 57% of our cash is in USD, 20% in EUR, and 23% in TRY. Excluding FX swap transactions, 71% of our cash is in USD and 29% in EUR. Alongside these sizeable cash outflows, we reinforced our liquidity position through a USD 1 billion Murabaha syndicated loan, further strengthening our financial flexibility and balance sheet resilience. Accordingly, consolidated debt as of March 31, 2026, increased to TRY206,347 million from TRY174,578 million as of December 31, 2025. Note that TRY16,230 million of our consolidated debt comprises lease obligations. After hedging transactions, 64% of our consolidated debt is in USD, 24% in EUR, 5% in CNY, and 7% in TRY. Due to cash disbursements, as of March 31, 2026, net debt1 increased to TRY48,827 million from TRY16,383 million as of December 31, 2025, with a net debt to EBITDA ratio of 0.42x.

We continued to manage the Group’s net FX position proactively, taking into account prevailing hedging costs and the relatively stable FX environment. Accordingly, we maintained our medium-term net FX target range of between minus USD1.5 billion and plus USD1.5 billion. As of quarter-end, the Group’s short net FX position stood at USD1.2 billion, including the hedging portfolio and advance payments.

Capital expenditures, including non-operational items, increased to TRY76,583 million in Q126, mainly driven by the 5G license amounting to USD1.2 billion (excluding VAT). Operational capital expenditures (excluding license fees) at the Group level were at 21.5% of total revenues.

(1) Our net debt calculation includes financial assets at fair value, whether through other comprehensive income or through profit and loss, reported under current and non-current assets, as well as financial assets at amortized cost. Required reserves held in CBRT balances are not included in total cash and net debt calculation.

Operational Review of Turkcell Türkiye

(1) Including mobile, fixed broadband, IPTV, and wholesale (MVNO&FVNO) subscribers 

(2) Superbox subscribers are included in mobile subscribers. 

(3) Churn figures represent average monthly churn figures for the respective periods.

Our total subscriber base expanded by 642 thousand in Q126, reaching 44.5 million thanks to segment-based offers that provide customers with tailored alternatives. In the postpaid segment, net additions reached 661 thousand, leading to our strongest total mobile net additions over the past 14 quarters. This brought the share of postpaid subscribers in the total mobile base to 81%, exceeding 32 million. We observed an improvement in mobile churn, which declined by 1.1pp compared with Q425 and by 0.1pp versus Q125, thanks to effective churn management and a relatively rationalized market environment. In the prepaid segment, we saw a notable moderation in net subscriber losses this quarter unlike in previous quarters, supported by our customer-centric tariffs and fewer tourist-related disconnections.

Mobile ARPU (excluding M2M) remained broadly flat, declining by 0.4% year-on-year, mainly due to the lagged impact of last year’s record-high competitive environment and persistently elevated inflation.

On the fixed side, our subscriber base declined slightly in Q1 2026, recording a net loss of 4 thousand, mainly due to our reduced focus on the ADSL segment. In the fiber segment, we maintained strong momentum in Turkcell fiber, achieving 21 thousand net additions in the quarter and 111 thousand on a yearly basis, supported by continued demand for high-speed connectivity. Residential fiber ARPU increased by 9.7% year-on-year, mainly driven by active upselling and pricing actions, and the growing contribution of our IPTV offering. As part of our “Technology Leadership in Türkiye” strategy, we launched our “UltraFiber” packages in March, offering ultra-high-speed connectivity to households for the first time in Türkiye with download speeds of 2, 5, and 10 Gbps.

In line with our fiber-focused strategy, we continued expanding our infrastructure footprint by adding 138 thousand new homepasses, reaching a total of 6.5 million, with the take-up rate at 41.8%.

TECHFIN

Paycell continued its steady growth trajectory as the primary performance contributor in the techfin segment, recording a 15.3% year-on-year increase in revenues. POS solutions and mobile payments were the main drivers of this performance in this quarter. Among all business lines, POS solutions delivered the strongest growth, as revenues grew by 37% year-on-year. This robust revenue performance was supported by broadening transaction volumes, particularly in physical POS, which recorded 150.4% year-over-year volume expansion. Furthermore, non-group revenues continued to gain prominence, with their share of total revenues increasing to 83%, mainly driven by rising number of users. As the POS business accounted for a larger share of the revenue mix, EBITDA margin declined by 7.4 percentage points to 31.8%.

Total transaction volume reached TRY55.5 billion, marking a 46.4% year-on-year increase. In addition to strong POS performance, Pay Later and QR Code contributed to the volume growth during the quarter. Pay Later strategic Services active users1 reached 3.3 million as of Q126.

Financell’s revenues contracted on a yearly basis due to ongoing installment limitations. The EBITDA margin improved to 39.1%, driven by lower funding costs while net income reached TRY149.5 million in this quarter.

Financell maintained its leadership position in financing sector holding a 44% market share2 by number loans. The company also captured a 9.9% market share in loans below TRY20,000 in banking and financing sector combined.

Financell’s loan portfolio reached TRY8.4 billion as of Q126, with 0.6 million active customers. There is significant market potential for Financell should regulatory conditions evolve favorably in line with macroeconomic dynamics, including potential increases in loan limits, which could in turn support Financell’s revenue growth.

(1) Unique customers who have utilized the "Pay Later" feature for digital service payments—including App Store, Google Play, and QR transactions—at least once within the preceding three-month period

(2) Source: Association of Financial Institutions, as of Q425

TURKCELL GROUP SUBSCRIBERS

As of March 31, 2026, the Turkcell Group had approximately 46.7 million registered subscribers. This figure is calculated by taking the number of subscribers of Turkcell Türkiye and of each of our subsidiaries. It includes the total number of mobile, fiber, ADSL, cable and IPTV subscribers of Turkcell Türkiye, BeST’s mobile subscribers and Kuzey Kıbrıs Turkcell’s mobile and fixed subscribers.

(1) Subscribers to more than one service are counted separately for each service. Including mobile, fixed broadband, IPTV, and wholesale (MVNO&FVNO) subscribers.

OVERVIEW OF THE MACROECONOMIC ENVIRONMENT

The foreign exchange rates used in our financial reporting, along with certain macroeconomic indicators, are set out below.

RECONCILIATION OF NON-GAAP FINANCIAL MEASUREMENTS:

We believe that Adjusted EBITDA, among other key metrics, facilitates performance comparisons from period to period and management decision making. It also enables performance comparisons between companies. Adjusted EBITDA as a performance measure eliminates potential differences caused by variations in capital structures (affecting interest expense), tax positions (such as the impact of changes in effective tax rates on periods or companies) and the age and book depreciation of tangible and intangible assets (affecting relative depreciation expense and amortization expense). We also present Adjusted EBITDA because we believe it is frequently used by securities analysts, investors and other interested parties in evaluating the performance of other mobile operators in the telecommunications industry in Europe, many of which present Adjusted EBITDA when reporting their results.

Our Adjusted EBITDA definition includes Revenue, Cost of Revenue excluding depreciation and amortization, Selling and Marketing expenses, Administrative expenses and Net impairment losses on financial and contract assets, but excludes finance income and expense, other operating income and expense, investment activity income and expense, share of profit of equity accounted investees and minority interest.

Nevertheless, Adjusted EBITDA has limitations as an analytical tool, and you should not consider it in isolation from, or as a substitute for, analysis of our results of operations, as reported under IFRS. The following table provides a reconciliation of Adjusted EBITDA, as calculated using financial data prepared in accordance with IFRS to net profit, which we believe is the most directly comparable financial measure calculated and presented in accordance with IFRS.

RECONCILIATION OF ARPU: ARPU is an operational metric and the methodology for calculating performance measures such as ARPU varies substantially among operators and is not standardized across the telecommunications industry, and reported performance measures thus vary from those that may result from the use of a single methodology. Management believes this metric is helpful in assessing the development of our services over time. The following table shows the reconciliation of Turkcell Türkiye revenues to such revenues included in the ARPU calculations for Q125 and Q126.

(1) Revenue from fixed corporate and wholesale business; digital business sales; tower business, and other non-subscriber-based revenues

(2) Revenues from Turkcell Türkiye included in ARPU calculation comprise telecommunication services revenue, equipment revenue and revenues which are not attributed to ARPU calculation.

ABOUT TURKCELL: Turkcell, headquartered in Türkiye, is a leading technology and telecommunications company offering a diverse portfolio of voice, data, and IPTV services across its mobile and fixed networks, alongside digital consumer, enterprise, and techfin solutions. The Turkcell Group operates in three countries: Türkiye, Belarus, and Northern Cyprus. In Q126, Turkcell Group reported revenue of TRY68.4 billion, with total assets of TRY618.2 billion as of March 31, 2026. Listed on both the NYSE and BIST since July 2000, Turkcell remains the only dual-listed company on these exchanges. Read more at www.turkcell.com.tr.

For further information, please contact Turkcell

Appendix A – Tables

Table: Net foreign exchange gain and loss details

Table: Income tax expense details

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
FOR THE THREE-MONTHS INTERIM PERIOD ENDED
31 MARCH 2026

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

INTERIM CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS PERIOD ENDED 31 MARCH 2026

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

CONDENSED CONSOLIDATED INTERIM STATEMENT OF FINANCIAL POSITION AS OF 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

The above interim condensed consolidated statement of financial position should be read in conjunction with the accompanying notes.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

CONDENSED CONSOLIDATED INTERIM STATEMENT OF FINANCIAL POSITION AS OF 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

The above interim condensed consolidated statement of financial position should be read in conjunction with the accompanying notes.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

CONDENSED CONSOLIDATED STATEMENT OF PROFIT OR LOSS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

The above interim condensed consolidated statement of profit or loss should be read in conjunction with the accompanying notes.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

CONDENSED CONSOLIDATED STATEMENT OF OTHER COMPREHENSIVE INCOME FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

 All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

The above interim condensed consolidated statement of other comprehensive income should be read in conjunction with the accompanying notes.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN EQUITY FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

(*) Included in Reserves in the consolidated statement of financial position.

The above consolidated statement of changes in equity should be read in conjunction with the accompanying notes.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

CONDENSED CONSOLIDATED FINANCIAL STATEMENT OF CASH FLOWS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

The above interim condensed consolidated statement of changes in equity should be read in conjunction with the accompanying notes.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

Turkcell Iletisim Hizmetleri Anonim Sirketi (the “Company” or “Turkcell”) was incorporated in Türkiye on 5 October 1993 and commenced its operations in 1994. The address of the Company’s registered office is Maltepe Aydinevler Mahallesi Inonu Caddesi No: 20, Kucukyali Ofispark/Istanbul.

The Company operates under a 25-year GSM license granted in and effective from April 1998 (2G License), a 20-year 3G license granted in and effective from April 2009 and a 13-year 4.5G license granted in August 2016 and effective from April 2016. On 7 April 2023, the 2G License has been extended to 30 April 2029. As of 31 March 2025, the Company’s shares are listed on Borsa Istanbul A.Ş. (“BIST”) and New York Stock Exchange (“NYSE”).

On 16 October 2025, within the scope of the tender organized by the Information and Communication Technologies Authority (ICTA) titled “Authorization Regarding the Establishment and Operation of Mobile Electronic Communications Infrastructure and the Provision of Services, and the Subjecting of Infrastructure and Services Under Existing Authorizations Expiring on 30 April 2029 to This Authorization,” the 5G spectrum allocation tender was concluded on 2 January 2026, following the first payment and the delivery of the Authorization Certificate to the Company. Accordingly, the Company will be able to continue providing mobile communication services from 30 April 2029, when the current GSM license authorization certificates expire, until 31 December 2042.

The interim condensed consolidated financial statements of the Company as at and for the three months ended 31 March 2026 comprise the Company and its subsidiaries (together referred to as the “Group”) and the Group’s interest in an associate.

These interim condensed consolidated financial statements were authorized for issue by the Board of Directors on 11 May 2026.

As of 31 March 2026, the ownership interest and voting rights of TVF Bilgi Teknolojileri Iletisim Hizmetleri Yatırım Sanayi ve Ticaret Anonim Sirketi (“TVF BTIH”) and IMTIS Holdings S.a r l. (“IMTIS Holdings”) in the Company are 26.2% and 19.8%, respectively. The proportion of the Company’s shares that are traded in domestic and foreign stock exchanges are 53.95%.

As of 31 March 2026, the Group’s immediate shareholder is TVF BTIH, which is wholly owned by Türkiye Varlik Fonu (“TVF”). TVF has been established with the Law No. 6741 and published in the Official Gazette dated 26 August 2016.

The Company’s board of directors consists of a total of nine non-executive members including three independent members as of 31 March 2026.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

These interim condensed consolidated financial statements for the three months ended 31 March 2026 have been prepared in accordance with IAS 34 Interim Financial Reporting.

These interim condensed consolidated financial statements do not include all the information and disclosures required in the annual financial statements, and should be read in conjunction with the Group’s annual consolidated financial statements as at 31 December 2025.

The accounting policies and presentation are consistent with those of the previous financial year and corresponding interim reporting period.

The financial statements of the Company and those of the subsidiaries, associates and joint ventures located in Türkiye and Turkish Republic of Northern Cyprus for the period ended 31 March 2026 were restated for the changes in the general purchasing power of Turkish Lira, which is their functional currency, based on International Accounting Standard No. 29 (“IAS 29”) “Financial Reporting in Hyperinflationary Economies”. IAS 29 requires that financial statements prepared in the currency of a hyperinflationary economy be stated in terms of the measuring unit current at the balance sheet date and that corresponding figures for previous periods be restated in the same terms.

The table below shows the evolution of CPI in the last three years and as of 31 March 2026:

New standards and interpretations

The accounting policies adopted in preparation of the consolidated financial statements as of 31 March 2026 are consistent with those of the previous financial year, except for the adoption of new and amended IFRS and IFRIC interpretations effective as of 1 January 2026 and thereafter. The effects of these standards and interpretations on the Group’s financial position and performance have been disclosed in the related paragraphs.

Amendment to IFRS 9 and IFRS 7 - Classification and Measurement of Financial Instruments; effective from annual reporting periods beginning on or after 1 January 2026 (earlier application permitted). These amendments:

The Group has no significant impact on its balance sheet and equity.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

Annual improvements to IFRS – Volume 11; effective from annual periods beginning on or after 1 January 2026 (earlier application permitted). Annual improvements are limited to changes that either clarify the wording in an Accounting Standard or correct relatively minor unintended consequences, oversights or conflicts between the requirements in the Accounting Standards. The 2024 list of amended Accounting Standard and accompanying guidance include the following:

The amendments have no significant impact on the Group’s consolidated financial statements.

Amendment to IFRS 9 and IFRS 7 - Contracts Referencing Nature-dependent Electricity; effective from annual periods beginning on or after 1 January 2026 (earlier application permitted). These amendments change the 'own use' and hedge accounting requirements of IFRS 9 and include targeted disclosure requirements to IFRS 7. These amendments apply only to contracts that expose an entity to variability in the underlying amount of electricity because the source of its generation depends on uncontrollable natural conditions (such as the weather). These are described as ‘contracts referencing nature-dependent electricity’.

The Group has no significant impact on its balance sheet and equity

Amendments to IAS 21 - Translation to a Hyperinflationary Presentation Currency; effective from annual periods beginning on or after 1 January 2027 (earlier application permitted). These narrow-scope amendments specify the translation procedures for an entity whose presentation currency is that of a hyperinflationary economy. The entity applies the amendments if:

The amendments aim to improve the usefulness of the resulting information in a cost-effective manner and reduce diversity in practice.

The Group expects no significant impact on its balance sheet and equity.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

IFRS 18 Presentation and Disclosure in Financial Statements; effective from annual periods beginning on or after 1 January 2027 (earlier application permitted). This is the new standard on presentation and disclosure in financial statements, with a focus on updates to the statement of profit or loss. The key new concepts introduced in IFRS 18 relate to:

To comply with paragraph 30 of IAS 8, it is expected that March year-end disclosures should about:

When preparing disclosures related to the adoption of IFRS 18 to comply with paragraph 30 of IAS 8, entities should consider the following principles:

a.    Disclosures are expected to become increasingly detailed as entities’ implementation process progresses toward 2027.

The level of detail that an entity includes in its disclosures will depend on the progress of its implementation activities, including those related to internal controls. For the year ending 31 March 2026, entities that have yet to make significant progress in implementation might only disclose that they are actively assessing the impact of IFRS 18 and that more comprehensive disclosures cannot reasonably be provided.

It may be appropriate to disclose preliminary figures, when the company has an appropriate and reliable basis for making such disclosures and provides clear explanations regarding their provisional nature. For example, an entity might quantify the effects on profit and loss subtotals. If the quantitative impact is not reasonably estimable, a statement to that effect should be included. An entity may disclose known and reasonably quantifiable impacts, but it is not expected to early provide IFRS 18 disclosures, such as an MPM reconciliation, before the application date.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

If management has publicly detailed anticipated impacts, such as in an investor presentation, the IAS 8 financial statement disclosures should be consistent with these communications.

Disclosures should be based on the information available through the date of issuance of the financial statements, not only the end of the reporting period.

The Group is in the process of assessing the impact of the amendments on financial position or performance of the Group.

IFRS 19 Subsidiaries without Public Accountability: Disclosures’; effective from annual periods beginning on or after 1 January 2027 (earlier application permitted). This new standard and amendments works alongside other IFRS Accounting Standards. An eligible subsidiary applies the requirements in other IFRS Accounting Standards except for the disclosure requirements and instead applies the reduced disclosure requirements in IFRS 19. IFRS 19’s reduced disclosure requirements balance the information needs of the users of eligible subsidiaries’ financial statements with cost savings for preparers. IFRS 19 is a voluntary standard for eligible subsidiaries. A subsidiary is eligible if:

The standard is not applicable for the Group.

Amendment to IFRS 19 Subsidiaries without Public Accountability: Disclosures’; effective from annual periods beginning on or after 1 January 2027 (earlier application permitted). In developing the reduced disclosure requirements in IFRS 19, the IASB considered the disclosure requirements in other IFRS Accounting Standards as at 28 February 2021. When IFRS 19 was issued, it did not contain reduced versions of any disclosure requirements that were added or amended after that date. Subsequently, the IASB issued these amendments to help eligible subsidiaries by reducing disclosure requirements for Standards and amendments issued between February 2021 and May 2024, specifically:

The standard is not applicable for the Group.

Comparative information and revision of prior period financial information

The consolidated financial statements of the Group are prepared comparatively with the previous period in order to enable comparability of the financial position and performance trends. In order to comply with the presentation of the current period consolidated financial statements, comparative information is reclassified when deemed necessary and significant differences are disclosed. Significant changes in accounting policies and significant accounting errors are applied retrospectively and prior period financial statements are restated.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power

As part of its strategy to offer integrated communication and technology services and to ensure economic integrity, the Group has divided its main operating segments into two groups: “Turkcell Türkiye” and “Techfin.” Although some of these strategic segments provide similar services, they are affected by different economic conditions and geographical locations. Therefore, they are regularly reviewed by the authority responsible for making decisions regarding the Group’s operations, based on resource allocation and performance. The authority responsible for making decisions related to the Group's operations is the Board of Directors. However, the Board of Directors may delegate its powers excluding the non-delegable powers stipulated by law to the CEO and other executives.

Turkcell Türkiye reportable segment includes the Groups’s mobile, fixed telecommunications, digital services and digital business services operations of Turkcell, Superonline Iletisim Hizmetleri A.S. (“Turkcell Superonline”), Turkcell Satış A.S’s (“Turkcell Satış”), Turkcell Dijital Is Servisleri A.S. (“Turkcell Dijital”), group call center operations of Global Bilgi Pazarlama Danismanlik ve Cagri Servisi Hizmetleri A.S. (“Turkcell Global Bilgi”), Turktell Bilisim Servisleri A.S. (“Turktell”), Atmosware Teknoloji Egitim ve Danismanlik A.S (“Atmosware Teknoloji”), Turkcell Teknoloji Arastirma ve Gelistirme A.S. (“Turkcell Teknoloji”), Ultia Teknoloji Yazilim ve Uygulama Gelistirme Ticaret A.S. (“Ultia”), Kule Hizmet ve Isletmecilik A.S. (“Global Tower”), Turkcell Gayrimenkul Hizmetleri A.S. (“Turkcell Gayrimenkul”), Lifecell Dijital Servisler ve Cozumler A.S. (“Lifecell Dijital Servisler”), Lifecell TV Yayin ve Icerik Hizmetleri A.S. (“Lifecell TV”), Lifecell Müzik Yayin ve Iletim A.S. (“Lifecell Müzik”), BiP Iletisim Teknolojileri ve Dijital Servisler A.S. (“BiP A.S.”), TDC Veri Hizmetleri A.Ş (“TDC”).

Techfin reportable segment includes all financial services operations of Turkcell Finansman A.Ş (“Turkcell Finansman”), Turkcell Ödeme ve Elektronik Para Hizmetleri A.Ş. (“Turkcell Ödeme”),Paycell LLC(“Paycell LLC”), Paycell Europe GmbH (“Paycell Europe”), Turkcell Sigorta Aracılık Hizmetleri A.Ş. (“Turkcell Sigorta”), Sofra Kurumsal ve Ödüllendirme Hizmetleri A.Ş (“Sofra”), Turkcell Dijital Teknolojileri Limited (“Turkcell Dijital Teknoloji”), and Turkcell Dijital Sigorta A.Ş. (“Turkcell Dijital Sigorta”). The operations of these legal entities aggregated into one reportable segment as the nature of services are similar and most of them share smilar economic characteristics.

Other operating segment comprises telecommunications, digital services, and energy-related activities outside Türkiye. This segment included CJSC Belarusian Telecommunications Network (“BeST”), Kıbrıs Mobile Telekomunikasyon Limited Sirketi (“Kıbrıs Telekom”), East Asian Consortium B.V. (“Eastasian”), Lifecell Ventures B.V (“Lifecell Ventures”), Lifetech LLC (“Lifetech”), Beltower LLC (“Beltower”), Lifecell Digital Limited (“Lifecell Digital”), Yaani Digital BV (“Yaani”), BiP Digital Communication Technologies B.V (“BiP B.V.”), Turkcell Global Bilgi non Group call center activities, Turkcell Enerji Çözümleri ve Elektrik Satış Ticaret A.Ş. (“Turkcell Enerji”), Boyut Grup Enerji Elektrik Üretim ve İnşaat Sanayi ve Ticaret A.Ş. (“Boyut Enerji”) and Turkcell Yeni Teknolojiler Girişim Sermayesi Yatırım Fonu (“Turkcell GSYF”).

The Board primarily uses adjusted EBITDA to assess the performance of the operating segments. Adjusted EBITDA definition includes revenue, cost of revenue excluding depreciation and amortization, selling and marketing expenses and administrative expenses.

Adjusted EBITDA is not a financial measure defined by IFRS as a measurement of financial performance and may not be comparable to other similarly titled indicators used by other companies. Reconciliation of Adjusted EBITDA to the consolidated profit for the year is included in the accompanying notes.

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)

Revenue from financial services comprise of interest income generated from consumer financing activities, The Group has interest income amounting to TRY 1,334,773 as of 31 March 2026 (31 March 2025: TRY 1,519,563).

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS INTERIM PERIOD ENDED 31 MARCH 2026

(All amounts disclosed in the consolidated financial statements and notes have been rounded off to the nearest thousand currency units and are expressed in terms of purchasing power of Turkish Lira as of 31 March 2026 unless otherwise stated.)