Answers · UK 2025/26

What happens if I exceed ISA allowance UK?

If you accidentally pay more than the £20,000 annual ISA limit in 2025/26, HMRC will normally remove the excess (and any growth on it) from the ISA wrapper and tax it as a normal taxable investment. There is no automatic penalty fine but interest and capital gains from the excess become taxable.

Last updated: 16 May 2026Last reviewed: 16 May 2026How we verify

Full answer

HMRC monitors ISA subscriptions through provider reporting after each tax year. If you breach the £20,000 limit (which includes any combination of cash ISA, stocks and shares ISA, innovative finance ISA and Lifetime ISA up to its £4,000 sub-cap), the excess is identified and HMRC writes to you. Process: (1) they tell you which provider holds the excess; (2) typically the most recent subscriptions are unwound — the excess and any income or growth on it are withdrawn from the ISA wrapper; (3) any tax on the now-taxable income or gains is collected through self-assessment or PAYE. Do not try to fix it yourself by transferring or withdrawing before HMRC contacts you — let them direct the repair. Common cause: paying into two cash ISAs in the same tax year used to breach the rules, but from 6 April 2024 you can subscribe to multiple ISAs of the same type within the same year as long as total stays within £20,000. Lifetime ISA over-payment (above £4,000) is automatically returned by the provider and any government bonus on it withdrawn.