APRIL 28, 2026 BUSINESS UPDATE Exhibit 99.1

1Edison International | April 2026 Business Update Statements contained in this presentation about future performance, including, without limitation, operating results, capital expenditures, rate base growth, dividend policy, financial outlook, and other statements that are not purely historical, are forward-looking statements. These forward-looking statements reflect our current expectations; however, such statements involve risks and uncertainties. Actual results could differ materially from current expectations. These forward-looking statements represent our expectations only as of the date of this presentation, and Edison International assumes no duty to update them to reflect new information, events or circumstances. Important factors that could cause different results include, but are not limited to the: • ability of SCE to recover its costs through regulated rates, timely or at all, including uninsured wildfire-related costs (including amounts paid for self-insured retention and co-insurance, and amounts not recoverable from the Wildfire Fund), and costs incurred for wildfire restoration efforts and to mitigate the risk of utility equipment causing future wildfires; • the cybersecurity of Edison International's and SCE's critical information technology systems for grid control and business, employee and customer data, and the physical security of Edison International's and SCE's critical assets and personnel; • risks associated with the construction, operation, and maintenance of electrical facilities, including worker, contractor, and public safety issues, the risk of utility assets causing or contributing to wildfires, failure, availability, efficiency, and output of equipment and facilities, and availability and cost of spare parts; • impact of affordability of customer rates on SCE's ability to execute its strategy, including the impact of lower-than-expected load growth and higher operating and capital costs (due to factors such as supply chain constraints, tariffs, inflation, and rising interest rates), which could affect SCE’s ability to obtain regulatory approval of, or cost recovery for, operations and maintenance expenses and proposed capital investment projects, as well as influence legislative actions; • ability of SCE to update its grid infrastructure to maintain system integrity and reliability, and meet electrification needs; • ability of SCE to implement its operational and strategic plans, including its Wildfire Mitigation Plan, its target energization times and capital investment program, including challenges related to project site identification, public opposition, environmental mitigation, construction, permitting, contractor performance, changes in the California Independent System Operator's (“CAISO”) transmission plans, and governmental approvals; • risks of regulatory or legislative restrictions that would limit SCE's ability to implement operational measures to mitigate wildfire risk, including Public Safety Power Shutoff (“PSPS”) and fast curve settings, when conditions warrant or would otherwise limit SCE's operational practices relative to wildfire risk mitigation; • ability of SCE to obtain safety certifications from the Office of Energy Infrastructure Safety of the California Natural Resources Agency (“OEIS“); • risk that the California Wildfire Legislation or anticipated new California legislation does not effectively mitigate the significant exposure faced by California investor-owned utilities related to liability for damages arising from catastrophic wildfires where utility facilities are alleged to be a substantial or contributing cause, including the longevity of the Wildfire Fund and the California Public Utilities Commission (“CPUC”) interpretation of and actions under the California Wildfire Legislation, including its interpretation of the clarified prudency standard; • ability of Edison International and SCE to effectively attract, manage, develop and retain a skilled workforce, including its contract workers; • decisions and other actions by the CPUC, the Federal Energy Regulatory Commission, and the United States Nuclear Regulatory Commission, the California legislature and other governmental authorities, including decisions and actions related to nationwide or statewide crisis, approval of regulatory proceeding settlements, determinations of authorized rates of return or return on equity, the recoverability of wildfire-related and debris flow-related costs, issuance of SCE's wildfire safety certification, reforming wildfire-related liability protections available to California investor-owned utilities, wildfire mitigation efforts, approval and implementation of electrification programs, and delays in executive, regulatory and legislative actions; • governmental, statutory, regulatory, or administrative changes or initiatives affecting the electricity industry, including the market structure rules applicable to each market adopted by the North American Electric Reliability Corporation, CAISO, Western Electricity Coordinating Council, and similar regulatory bodies in adjoining regions, and changes in the United States' and California's environmental priorities that lessen the importance placed on greenhouse gas reduction and other climate related priorities; • potential for penalties or disallowances for non-compliance with applicable laws and regulations, including fines, penalties and disallowances related to customer notifications and to wildfires where SCE's equipment is alleged to be associated with ignition; • extreme weather-related incidents (including events caused, or exacerbated, by climate change), such as wildfires, debris flows, flooding, droughts, high wind events and extreme heat events and other natural disasters (such as earthquakes), which could cause, among other things, worker and public safety issues, property damage, outages and other operational issues (such as issues due to damaged infrastructure), PSPS activations and unanticipated costs; • risks associated with the decommissioning of San Onofre, including those related to worker and public safety, public opposition, permitting, governmental approvals, on-site storage of spent nuclear fuel and other radioactive material, delays, contractual disputes, and cost overruns; • risks associated with cost allocation resulting in higher rates for utility bundled service customers because of possible customer bypass or departure for other electricity providers such as Community Choice Aggregators (“CCA,” which are cities, counties, and certain other public agencies with the authority to generate and/or purchase electricity for their local residents and businesses) and Electric Service Providers (entities that offer electric power and ancillary services to retail customers, other than electrical corporations (like SCE) and CCAs); • actions by credit rating agencies to downgrade Edison International or SCE’s credit ratings or to place those ratings on negative watch or negative outlook. Other important factors are discussed under the headings “Forward-Looking Statements”, “Risk Factors” and “Management’s Discussion and Analysis” in Edison International’s Form 10-K and other reports filed with the Securities and Exchange Commission, which are available on our website: edisoninvestor.com. These filings also provide additional information on historical and other factual data contained in this presentation. Forward-Looking Statements

2Edison International | April 2026 Business Update Wildfire Mitigation Financial Information AppendixIntroduction Electrifying the Future: Customers and Clean Energy Edison International leads the transformation of the electric power industry One of the nation’s largest electric-only utilities, with over 5 million customer accounts in 50,000 square-mile service area EIX’s principal subsidiary, with $38–41 billion electric infrastructure investment opportunity from 2026 through 2030 Growth driven by investment in strengthening and modernizing the grid and advancing California’s aggressive climate goals Wires-focused rate base, with limited power generation ownership (<20% of power delivered from owned generation) Partners with large commercial, industrial, and institutional organizations to navigate the energy transition by providing integrated energy management and sustainability solutions Clients include 48 of the world’s largest companies Focused on opportunities in clean energy, advancing electrification, building a modernized and more reliable grid, and enabling customers’ technology choices

3Edison International | April 2026 Business Update Wildfire Mitigation Financial Information AppendixIntroduction Electrifying the Future: Customers and Clean Energy Thesis: Wires-focused utility investing in reliability, resiliency, and climate adaptation to enable clean energy transition Constructive California and Federal regulatory structures Aggressive climate goals met with clean, efficient, economywide electrification Significant investment required to ensure the grid is reliable, resilient, and ready for widespread electrification Investment in electric-led clean energy future results in strong rate base and dividend growth Decoupling of sales Forward-looking ratemaking Wildfire prudency standard California GHG reduction Helping customers make clean energy choices Address wildfire risk and climate adaptation needs Infrastructure replacement Electrification infrastructure ~7% 2025–2030 rate base CAGR Target dividend payout of 45–55% of SCE core earnings

4Edison International | April 2026 Business Update Wildfire Mitigation Financial Information AppendixIntroduction Electrifying the Future: Customers and Clean Energy California’s regulatory mechanisms provide revenue certainty Revenue Decoupling means earnings aren’t affected by changes in electricity sales Long-standing regulatory mechanism that breaks the link between retail electricity sales and revenue; promotes energy efficiency, helps stabilize customer bills, and supports environmental goals Changes in sales only affect timing of cash collection Balancing Accounts allow SCE to collect and refund differences to authorized revenue SCE has several balancing accounts, including for variances in sales volume, such as those related to weather Fuel & purchased power recovered on forecast basis, with over/under-collections trued-up via balancing accounts Forecast Ratemaking reduces regulatory lag Four-year GRC cycle with forward-looking test year and attrition year increases CPUC has historically authorized mechanism that gives SCE opportunity to offset some inflationary price increases Cost of capital proceedings on three-year cycle separate from GRC with mechanism to reasonably adjust cost of capital if market conditions change significantly during cycles

6Edison International | April 2026 Business Update Financial Information AppendixIntroduction Wildfire Mitigation Electrifying the Future: Customers and Clean Energy SB 254 (2025) & Natural Catastrophe Resiliency Study AB 1054 (2019) & SB 599 (2022) SCE Safety Certification Wildfire Insurance Fund AB 1054 and SB 254-Related Edison for the Record Map of SCE’s Service Area Stories and Videos on SCE’s Wildfire Mitigation Efforts and PSPS Other Useful Links and Resources1 Weather Stations Wildfire Cameras PSPS Information PSPS Decision Making Role of Weather in PSPS SCE Wildfire Safety Webpage Wildfire Mitigation Plan & Related Documents Vegetation Management Southern California Wildfires Document Library (including ESIRs and Section 315 letters) Situational Awareness Wildfire Mitigation 1. This page contains links to third-party websites, provided for the convenience of investors. Direct links to documents and information issued by third parties are provided on this page should not be construed as an endorsement or adoption of or an agreement with such content by Edison International or SCE. Third-party content is the responsibility of the third-party, and Edison International and SCE disclaim all liability for any statements made in such third-party content

7Edison International | April 2026 Business Update Financial Information AppendixIntroduction Wildfire Mitigation Electrifying the Future: Customers and Clean Energy SCE’s 2026–2028 Wildfire Mitigation Plan is a layered defense strategy to safeguard our communities Distribution hardening Additional 700+ miles of covered conductor and targeted undergrounding Transmission hardening Enhanced standards and proactive upgrades to reduce ignition risk on transmission infrastructure New technology deployment Deploying new and expanded tools to identify and prevent ignition risks early Public Safety Power Shutoffs (PSPS) Last-resort tool to prevent ignitions during extreme weather; focused on reducing impacts Situational awareness Using weather stations, HD cameras, and forecasting to monitor and respond to wildfire risk Continued investment builds on ongoing efforts to reduce the risk of wildfires associated with utility equipment while applying latest learnings Vegetation management Removing hazardous trees and maintaining clearances to prevent vegetation-related ignitions Aerial suppression Supporting aerial firefighting resources to improve rapid wildfire response and public safety Refine other strategies Continuously improving mitigation through lessons learned, modeling, and utility collaboration

8Edison International | April 2026 Business Update Financial Information AppendixIntroduction Wildfire Mitigation Electrifying the Future: Customers and Clean Energy SCE is seeing proof points and results from its substantial wildfire mitigation efforts 1. Since 2018 and as of March 31, 2026 2. Refers to the ignition drivers covered conductor is designed to mitigate 7,110+ MILES OF COVERED CONDUCTOR1 2.8 MILLION+ TRIMS AND REMOVALS IN HFRA1 1.8 MILLION+ HFRA INSPECTIONS1 ~2000 WEATHER STATIONS1 ~200 HD CAMERAS1 No ignitions due to failure of covered conductor2 ~90% visual coverage of SCE’s High Fire Risk Area

9Edison International | April 2026 Business Update Financial Information AppendixIntroduction Wildfire Mitigation Electrifying the Future: Customers and Clean Energy California has a comprehensive wildfire risk reduction profile, benefiting customers and investors Suppression CAL FIRE Budget: Doubled since 2017-18 CAL FIRE Staffing: >90% increase since 2017-18 CAL FIRE’s fleet is the largest civil aerial firefighting fleet in the world Legislation SB 254 passed Sept. 2025 AB 1054 passed July 2019 Codified prudent manager standard $21+ billion initial wildfire fund and $18 billion continuation account Regulation Wildfire Mitigation Plan Safety Certification Substantial approved funding for wildfire mitigation

10Edison International | April 2026 Business Update Financial Information AppendixIntroduction Wildfire Mitigation Electrifying the Future: Customers and Clean Energy SB 254 is a key action that demonstrates support for IOU financial stability and its importance for customer affordability… 1. References to “Wildfire Fund” refer to the fund established under AB 1054 in 2019; “New fund” refers to the Continuation Account established under SB 254. Funding of the Continuation Account is dependent upon a determination by the fund administrator and CPUC authorization of extending customer charges 2. If the administrator winds up and terminates the account before the final installment payment is paid, IOUs shall provide one-half of the remaining unpaid installment payments as rate credits to its ratepayers 3. Any remaining value in the Wildfire Fund rolls over to the new fund after satisfying covered wildfires 4. Subject to CPUC approval; SB 254 was signed by the governor on September 19, 2025, which is the effective date of the bill 5. Based on the assumption that SCE’s share will be determined according to its allocation of the IOU contributions to the Continuation Account    Excludes $6Bn in wildfire capex from rate base Creates $18Bn fund with no upfront contribution1 Funded 50/50 by customers and IOUs – IOUs: $300MM/year for 2029–2045 – plus $3.9Bn over 5 years if need determined by administrator2 – Customers: $900MM/year for 2036–2045 SCE share: 47.85% (~$145MM/year starting 2029) New fund available only for wildfires ignited after Sept. 19, 2025 (SB 254’s effective date); initial fund available only for wildfires ignited before effective date1,3 Enhances framework for liability cap, claims, and financing Liability cap now based on year of ignition—improving certainty of amount—rather than year of disallowance If Wildfire Fund1 exhausted, IOU may issue securitized bonds to fund claims payments for covered wildfires ignited between Jan. 1, 2025, and Sept. 19, 20254 If required to reimburse new fund, IOU may reduce reimbursement by amount of contributions paid Gives IOUs right of first refusal for subrogation claim sales for wildfires ignited after SB 254’s effective date IOUs to securitize $6Bn of wildfire mitigation capital spending (SCE share: ~$2.9Bn)5 Constructive for potential Eaton Fire losses