5 reasons to file your tax return early

Nearly 300,000 people filed their tax returns in the first week of the new financial year, beating the deadline by almost 10 months.

New HMRC figures show 299,419 self-assessment tax returns for 2024-25 were submitted between 6 April and 12 April 2025 – a slight increase on last year’s early total of 295,250.

However, fewer taxpayers filed on the very first day of the tax year: 57,815 returns were submitted on 6 April, down from 67,870 in 2024. 

If you haven’t filed yet, there are good reasons to get ahead. We explain five key benefits of submitting your return early.

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1. More time to plan and budget

Some people only find out how much tax they owe after completing their return.

If you file early, you'll have several months to make plans to pay off the bill, which doesn't need to be done until 31 January 2026. If you wait until the last minute, you may find you can't pay the full amount owed, and could face a fine.

If you're self-employed and pre-pay your tax by payments on account, any refunds you're owed by HMRC won’t be processed until it receives your tax return. By filing several months in advance, when the tax office is likely to be quieter, you might find you'll receive rebates quicker.

Finally, if this is your first time filing a tax return, the process can take longer than usual as you’ll first need to register with HMRC. 

It will post you a Unique Taxpayer Reference (UTR) number and a separate access code to use its online services; only then can you file your tax return. This process can take a couple of weeks, or even longer during peak times in January. To avoid the risk of missing the deadline, getting this done early will save you stress and a potential fine.

• Find out more: how to fill in a self-assessment tax return

2. Beat these deadlines

Whether it's your first, fifth or fifteenth tax return, there are several deadlines to watch out for, and starting the self-assessment process early means there's less risk of missing them.

Here's a quick rundown of the key dates to add to your diary:

• 31 October 2025 If you want to file a paper return, make sure you get it to the tax office by Halloween. 
• 31 January 2026 You have until midnight on this day to get your online tax return to HMRC. This is also the date you need to pay your bill by. If you have been self-employed for a full year, you may be asked to start paying tax in advance through the ‘payments on account’ arrangement. The first instalment is due on this date, too.
• 6 April 2026 The first day of the new financial year is when any new tax rates and regulations announced in the Chancellor’s Autumn Statement and Spring Budget will come into force. It's also the first date that you can file your self-assessment for the previous financial year.
• 31 July 2026 If you're self-employed and use payments on account, the second instalment is due on this date. 

3. Avoid costly fines

HMRC takes a dim view of tardy taxpayers, and this year it's imposing heavier penalties for customers who don't file and pay on time.

An estimated 1.1 million people filing 2023-24 tax returns missed the deadline of 31 January 2025, according to HMRC. They would have faced hefty fines as a result.

Fines for filing late

HMRC will issue you with an initial £100 penalty if you fail to file before the final online returns deadline of 31 January. Even if you're only a day late. Other charges are as follows:

• £10 a day after three months, up to a maximum of £900.
• After six months, a further penalty of 5% of the tax due or £300, whichever is greater.
• After 12 months, another 5% or £300 charge, whichever is greater.

Late payment fees

You may also be charged interest from the date the payment was due. 

As of 6 April 2025, interest rates for late payments are now set at the Bank of England base rate plus 4% – up from base rate plus 2.5% last year. 

With the base rate currently at 4.25%, any money you owe the taxman will now rack up interest at a rate of 8.25%.

The longer you leave it, the higher the fine and the interest incurred.

As well as interest charges, you can also face the following penalties for late payments:

• After 30 days a charge equal to 5% of the tax outstanding
• After six months (31 July) a further 5%.
• After 12 months (31 January the following year) an additional 5%.

4. Prevent mistakes

Giving yourself more time means you’re less likely to have to rush your tax return, which can lead to careless mistakes. 

You should double or triple-check all of the information to correct any errors before submitting to HMRC. This means you'll also have plenty of time to source extra paperwork, if you need to.

HMRC can also impose fines for errors, with penalties based on the amount of tax you owe and the kind of error HMRC deems you to have made. For example, it could rule that you've simply made a careless mistake or judge the error as a deliberate attempt to hide something.

• Find out more: late tax returns and penalties for mistakes

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5. Get help if needed

If you're finding any part of the process difficult or need to ask a question about self-assessment, you can call HMRC on 0300 200 3310. Now is the ideal time to pick up the phone and ask for help. Calling later in the year and just before the deadline in January could mean you're hanging on the phone for a lot longer. 

If you owe less than £30,000, you may be able to sign up for a payment plan. This allows you to pay in smaller instalments, but you’ll still be charged interest.

To set up a payment plan online yourself, you'll need to be within 60 days of the 31 January payment deadline and not have any other payment plans or debts with HMRC. For other circumstances, call the Payment Support Service on 0300 200 3835.