Book size: 4800; Registration: Reg S Only; Comments: EUR500m 12yr Green cpn fxd 4.102% at 100, yld 4.102%. Spread: MS + 115bps. DBR 4.000% 01/04/37 + 120.0bps (bid 110.06, HR 96%). Par Call: 3m. LEI: 213800H7NWVLCWAVKA15;

Reoffer: 12yr: MS+115bp / 100 / 4.102% Benchmark: 12yr: DBR 4.000% 01-Apr-37 @ 110.06 / B+120bp / HR 96% Issuer: South Eastern Power Networks plc Ticker: UKPONE Country: GB Issuer LEI: 213800H7NWVLCWAVKA15 Issuer Ratings: A3 (negative) / A- (stable) / BBB+ (stable) (Moody's/S&P/Fitch) Expected Issue Ratings: A3 / A- / A- (Moody's/S&P/Fitch) Format: Senior, Unsecured, Reg S, Category 2, Bearer, NGN, Green Settlement Date: 17-Mar-26 (T+5) Size: €500m Tenor: 12-year Maturity Date: 17-Mar-38 Reoffer: MS+115bp, 100, 4.102% Coupon: 4.102%, FXD, Annual, Act/Act (ICMA) Benchmark: DBR 4.000% 01-Apr-37 + 120bp (bid 110.06, HR 96%) Par Call: 3-month ISIN: XS3317522822 Denominations: €100k+€1k Optional Redemption: Restructuring Event Noteholder Put Docs/Listing/Governing Law: In accordance with the Issuer's GBP 10 billion EMTN Programme dated 30-Jul-25, as supplemented on 6-Mar-26 / London Stock Exchange (Main Market) / English Law Clearing: Euroclear / Clearstream, Luxembourg Use of Proceeds: Net proceeds will be used in accordance with the Issuer's Green Bond Framework to finance and/or refinance new and/or existing green projects Selling Restrictions: As per the Base Prospectus dated 30-Jul-25 Joint Bookrunners: MUFG, NatWest, RBC Capital Markets (B&D), Société Générale Target Market: Manufacturer target market (EU MiFID II and UK MiFIR product governance) is eligible counterparties and professional clients only (all distribution channels). No PRIIPs or UK PRIIPS key information document (KID) has been prepared as not available to retail in EEA or UK Advertisement: The Offering Circular and any supplements are available on the website of the London Stock Exchange www.londonstockexchange.com. The Final Terms, when published, will be available on the website of the London Stock Exchange www.londonstockexchange.com Marketing URL: https://dealroadshow.com/e/SPN26 or visit https://dealroadshow.com and enter code: SPN26 Timing: ToE 14.45 UKT / FTT 15.05 UKT

Net proceeds will be used in accordance with the Issuer’s Green Bond Framework to finance and/or refinance new and/or existing green projects