Self Assessment deadlines

These are the deadlines for the 2025 to 2026 tax year. They apply to income, gains and cryptoasset disposals.

Deadline What you must do
5 October 2026Tell HMRC you need to send a tax return, if you have not sent one before
31 October 2026Send a paper tax return
31 January 2027Send your online tax return and pay what you owe
WarningYou’ll get a penalty if you miss these deadlines.

If you miss a deadline

You may have to pay interest and penalties. The longer you leave it, the more you pay.

Cryptoassets

Disposals of cryptoassets are reported on the same return and by the same deadlines. Find out about cryptoassets and Self Assessment.

If you have already missed a deadline

Send your return as soon as you can. Penalties are lower the sooner you file. If you have a reasonable excuse you can appeal.