Tax Planning: UK Tax Year End — Key Dates and Deadlines for 2025/26
The 2025/26 tax year ends on 5 April 2026, and with just weeks remaining, time is running out to make the most of your annual allowances. Every year, billions of pounds in tax-efficient allowances go unused simply because people miss the deadline. Whether it is your £20,000 ISA allowance, £3,000 capital gains exemption, or £60,000 pension annual allowance, these entitlements cannot be carried forward — once 6 April arrives, they vanish. This guide sets out every key date and deadline you need to know before the 2025/26 tax year closes, along with practical action items to help you retain as much of your money as possible. With the personal allowance frozen at £12,570 since 2021/22 and fiscal drag pulling more earners into higher tax bands, proactive tax planning has never been more important. The Bank of England base rate sits at 3.75% as of March 2026, meaning cash savings and fixed-income returns remain meaningful — but only if sheltered from tax efficiently. Below you will find a month-by-month calendar of what resets on 6 April, a breakdown of every allowance and threshold for 2025/26, and a checklist of actions to complete before the year-end. We have included worked examples and charts using verified figures from gov.uk and HMRC.