TSB deal makes Santander UK (SNTUF) a top-3 UK current account bank

Rhea-AI Filing Summary

Santander UK plc has completed its cash acquisition of the entire issued share capital of TSB Banking Group plc for £2.65 billion plus an estimated £213 million TNAV Variation, with a final adjustment to follow once TSB’s tangible net asset value is confirmed.

The deal, funded from Santander UK’s existing cash and support from Banco Santander, makes Santander UK the third largest UK bank by personal current account balances and number four in mortgages. Management targets at least £400 million of cost synergies and aims to lift return on tangible equity to 16% by 2028, while maintaining a CET1 capital ratio of 14% after completion.

Santander UK intends to integrate TSB Bank plc through a Part VII banking business transfer scheme in the first half of 2027, subject to court sanction and regulatory non‑objection.

Positive

• Transformative UK retail scale: Acquisition of TSB makes Santander UK the third largest bank in the UK by personal current account balances and number four in mortgages, significantly strengthening its competitive retail banking position.
• Clear profitability and synergy targets: Management expects at least £400 million of cost synergies and is targeting a 16% return on tangible equity by 2028, indicating a defined value-creation plan from the integration.
• Capital strength maintained: After completion, Santander UK’s CET1 capital ratio is 14%, which the company states is above minimum regulatory requirements and its operational targets, supporting balance sheet resilience post-transaction.

Negative

• None.

Insights

Banking sector analyst

Santander UK’s TSB purchase materially scales its UK retail franchise with defined synergy and capital targets.

Santander UK has acquired all of TSB for £2.65 billion plus an estimated £213 million TNAV Variation. The transaction is financed with existing cash resources and funding from Banco Santander, concentrating group capital into the UK market with full ownership of TSB.

The combination creates the UK’s third largest bank by personal current account balances and number four in mortgages, signalling a much larger retail footprint. Management highlights at least £400 million of cost synergies and a targeted 16% return on tangible equity by 2028, suggesting a clear focus on profitability once integration progresses.

Post‑deal, Santander UK reports a CET1 capital ratio of 14%, which remains above minimum requirements and internal operational targets. A key execution step will be the planned Part VII banking business transfer scheme in the first half of 2027, which still depends on court sanction and regulatory non‑objection, so integration timing will hinge on these approvals.

Key Figures

Acquisition price: £2.65 billion Estimated TNAV Variation: £213 million Cost synergies: At least £400 million +5 more

8 metrics

Acquisition price £2.65 billion Cash consideration for entire issued share capital of TSB

Estimated TNAV Variation £213 million Estimated difference in TSB tangible net asset value between 1 Apr 2025 and 30 Apr 2026

Cost synergies At least £400 million Targeted cost synergies from integrating TSB into Santander UK

Target RoTE 16% Target return on tangible equity for Santander UK by 2028

Post-deal CET1 ratio 14% Santander UK CET1 capital ratio after completion of TSB acquisition

PRA approval date 19 March 2026 Prudential Regulation Authority approval of the acquisition

ECB approval date 14 April 2026 European Central Bank approval of the acquisition

Planned integration window First half of 2027 Intended Part VII banking business transfer scheme timing

Key Terms

tangible net asset value, TNAV Variation, CET1 capital ratio, return on tangible equity, +2 more

6 terms

tangible net asset value financial

"difference in TSB’s tangible net asset value between 1 April 2025 and 30 April 2026"

TNAV Variation financial

"TSB’s tangible net asset value between 1 April 2025 and 30 April 2026 (“TNAV Variation”)"

CET1 capital ratio financial

"After completion, the CET1 capital ratio of Santander UK will be 14%"

The CET1 capital ratio measures a bank’s core equity (common shares and retained earnings) as a share of its assets after those assets are adjusted for how risky they are. It shows how big a financial cushion the bank has to absorb losses without needing outside help, so investors use it like a fuel gauge: higher ratios mean more protection against bad loans or market shocks and lower chances of forced capital raises or regulatory action.

return on tangible equity financial

"expected to contribute to a targeted increase in Santander UK’s return on tangible equity to 16% by 2028"

Return on tangible equity measures how much profit a company generates for common shareholders using the ‘‘hard’’ capital on its balance sheet—equity after removing intangible items like goodwill and patents. Investors use it to judge the firm’s core profitability and capital efficiency, because it shows profit per dollar of tangible, real assets; think of it as earnings earned on cash, buildings and machinery rather than on acquired goodwill.

Part VII of the Financial Services and Markets Act 2000 regulatory

"through a banking business transfer scheme under Part VII of the Financial Services and Markets Act 2000"

cost synergies financial

"with cost synergies of at least £400 million"

Cost synergies are the expected savings when two businesses combine activities so they can eliminate duplicate work, negotiate better prices, or run things more efficiently—like two households moving in together to share rent, groceries and utilities. Investors care because these savings can boost profit margins and cash flow, improving returns and supporting a higher valuation if the projected cuts are realistic and actually achieved. Actual results may differ from projections, so promised cost synergies are closely watched in deal assessments.

Form 6-K: How Foreign Companies Report to the SEC →

Page 1 of 3 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 001-14928 SANTANDER UK PLC (Translation of registrant's name into English) 2 Triton Square, Regent's Place, London NW1 3AN, England (Address of principal executive office) Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F. Form 20-F . . . .X. . . . Form 40-F . . . . . . . .

Page 2 of 3 Announcement of Completion: Cash Acquisition of TSB Banking Group plc ("TSB") by Santander UK plc ("Santander UK") The boards of Santander UK and TSB are pleased to announce that Santander UK acquired the entire issued share capital of TSB on 30 April 2026, following satisfaction of the conditions to completion (the “Acquisition”). Approval of the Acquisition was received from the Prudential Regulation Authority on 19 March 2026 and the European Central Bank on 14 April 2026. The Acquisition was approved by the shareholders of Banco de Sabadell, S.A. (“Sabadell”) on 6 August 2025. The key terms of the Acquisition were announced by Banco Santander, S.A. on 1 July 2025. The consideration paid by Santander UK to Sabadell at completion for the entire issued share capital of TSB was £2.65 billion, plus Sabadell’s estimate of the difference in TSB’s tangible net asset value between 1 April 2025 and 30 April 2026 (“TNAV Variation”) amounting to approximately £213 million. The consideration paid at completion will be adjusted upwards or downwards once the final TNAV Variation has been determined after completion. Any adjustment will be paid as soon as possible after the final determination has been made. The transaction has been financed from Santander UK’s existing cash resources and from funding provided by its ultimate parent, Banco Santander, S.A. It is intended to integrate the business of TSB Bank plc into Santander UK through a banking business transfer scheme under Part VII of the Financial Services and Markets Act 2000 in the first half of 2027. This integration is conditional on court sanction and regulatory non-objection. The deal makes Santander UK the third largest bank in the UK by personal current account balances and number four in mortgages. The transaction is expected to contribute to a targeted increase in Santander UK’s return on tangible equity to 16% by 2028, with cost synergies of at least £400 million. After completion, the CET1 capital ratio of Santander UK will be 14% (above minimum requirement and operational targets). - Ends - Enquiries: Thuy Dinh, Investor Relations – ir@santander.co.uk Stewart Todd, Head of Communications and Responsible Banking – mediarelations@santander.co.uk

Page 3 of 3 SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. SANTANDER UK PLC By: / s / Roz Rule Name: Roz Rule Title: Company Secretary Dated: 1 May, 2026

FAQ

What did Santander UK (SNTUF) announce regarding TSB Banking Group?

Santander UK announced it has completed the cash acquisition of the entire issued share capital of TSB Banking Group plc.

The deal closed on 30 April 2026 after regulatory and shareholder approvals, bringing TSB fully under Santander UK’s ownership.

How much did Santander UK (SNTUF) pay to acquire TSB?

Santander UK paid £2.65 billion for TSB’s entire issued share capital plus an estimated £213 million TNAV Variation.

The total consideration will be adjusted up or down once TSB’s final tangible net asset value between April 2025 and April 2026 is determined.

How will the TSB acquisition affect Santander UK’s market position?

The acquisition makes Santander UK the third largest bank in the UK by personal current account balances and number four in mortgages.

This expanded scale strengthens its retail banking franchise and deepens its presence across key UK consumer banking segments.

What financial benefits does Santander UK expect from acquiring TSB?

Santander UK expects at least £400 million of cost synergies and is targeting a 16% return on tangible equity by 2028.

These goals reflect planned efficiency gains and improved profitability once TSB is fully integrated into the UK business.

How is Santander UK funding the TSB acquisition and what is its CET1 ratio?

The transaction is financed from Santander UK’s existing cash resources and funding from its ultimate parent, Banco Santander, S.A.

Following completion, Santander UK reports a 14% CET1 capital ratio, which remains above regulatory minimums and its operational targets.

When and how will TSB be integrated into Santander UK?

Santander UK intends to integrate TSB Bank plc via a Part VII banking business transfer scheme in the first half of 2027.

This process is conditional on court sanction and regulatory non‑objection, so legal and supervisory approvals remain key milestones.