Amending a personal tax return letter

You are entitled to amend entries on your personal self-assessment tax return within the “amendment window”. Where you completed and submitted your return electronically either using HMRC’s or commercial software, you can use it to make amendments. However, where you submitted a return in paper format you will need to write to HMRC with details of the corrections.

Tax return amendment window

There are different time limits in which an amendment can be made:

• where the orginal return was submitted within the normal filing deadline, one year from that date, the normal filing deadline is 31 January following the end of the tax year. For example, for 2023/24 the filing deadline is 31 January 2025 and the amendment window, 31 January 2026
• where HMRC’s notice requesting you submit a tax return is issued after 31 October following the end of the tax year concerned, it’s one year and three months from the date of issue of HMRC’s notice to file. For example, if HMRC issues a notice to file for 2023/24 on 10 November 2024 the deadline for submitting the form is 9 February 2025 and the amendment window is 9 February 2026
• where HMRC issues a notice closing an enquiry into your tax return, it’s 30 days from the date of issue of the notice.