The Autumn Budget 2026 announcement raises a specific tax on banks for a limited period. HM Treasury says the Bank Corporation Tax Surcharge will rise from 3% to 6% for 15 months, from 1 January 2027 to 31 March 2028. The surcharge will then return to 3%. The Government estimates the temporary increase will raise £1.5 billion to help fund support for households and businesses.
What is changing?
The change is to the bank surcharge, an additional corporation tax charge on banking profits. It is not a change to the main headline Corporation Tax rate. The Budget’s tax documents say the main rate remains 25%, while the surcharge rate is set at 6% during the temporary period. The announcement therefore adds three percentage points to the surcharge rate; it does not mean that every bank’s total tax bill rises by three percentage points of all its profits. A bank’s actual liability depends on the rules and its taxable profits.
Why is it temporary?
HM Treasury presents the increase as a time-limited contribution to fund immediate energy-bill support. The published dates matter: the higher surcharge is due to apply from the start of 2027 until the end of March 2028. The tax policy document says the measure is to be legislated for in Finance Bill 2026–27. Until legislation is enacted, the Budget announcement describes the Government’s policy plan rather than a fully implemented tax rule.
Mortgage Strategy reported that higher increases had been discussed before the Budget, including figures of 5% or 8%. Those were pre-Budget speculation in the publisher’s account, not the rate announced by HM Treasury. The confirmed proposal is a temporary rise in the surcharge from 3% to 6%.
What could it mean for property finance?
Mortgage Strategy also reported an expert’s view that a sustained increase could raise questions about the UK’s competitiveness for banking activity. It noted that lenders might respond to additional costs through mortgage pricing, fees, incentives or their appetite to lend. These are possible commercial responses, not outcomes announced by the Government. The Budget does not specify that mortgage rates or product fees will rise because of this measure, and the tax change alone cannot predict what any lender will do.
For home-buyers, landlords and property businesses, the practical approach is to compare actual mortgage offers and fees when arranging finance, rather than assume the surcharge will feed directly into a particular product. Banks’ tax positions and product decisions vary, and other funding costs and market conditions also affect pricing.
This is a summary of a Budget announcement, not tax or mortgage advice. The policy dates and rates should be checked against the final legislation and current HM Treasury documents. Sources: HM Treasury, Budget 2026 announcement and tax-policy documents; Mortgage Strategy’s report of 28 October 2026.