Benefits of filing your 2025/26 tax return early

The 2025/26 Self-Assessment tax return must be filed online by midnight on 31 January 2027. However, you do not have to wait until the deadline is approaching to file your return and there can be advantages in filing early.

Before filing your return, it is important to check that you have all the information you need. If you have employment or pension income to include on your return, you may need to wait until you have your P60. You should have that by 31 May 2026. Likewise, you may also need details of payrolled benefits and those reported on your P11D.

Here are seven reasons why filing your tax return early may be a good idea:

1. You will get it out of the way and avoid the stress of having to file it at the last minute.

2. If you have trading and/or property income, you will know whether you will need to start complying with MTD for ITSA from 6 April 2027 if you are not already in it. This will be the case if your combined trading and property income before deduction of expenses is £30,000 or more in 2025/26 The earlier you know, the longer you have to prepare.

3. You will know what tax you have to pay in advance and can ensure that you have the funds available to meet the tax bills, rather than being caught out at the last minute.

4. If you are owed a tax refund, you can claim the money back sooner.

5. If you make payments on account, once you know your 2025/26 tax liability you can check whether you need to reduce them.

6. If you file your return before 30 December 2026 and owe £3,000 or less, you can opt to have the tax that you owe collected through your 2027/28 tax code. This is equivalent to an interest-free instalment option.

7. If you are looking to get a mortgage and need proof of your income, filing your tax return will provide this.