Paper tax return deadline looming – 6 reasons to file online early

The deadline for submitting paper self-assessments is 31 October, but HMRC data shows just under 3% of customers filed their 2023-24 tax returns this way.

Instead, more than 97% of returns were submitted digitally by the online deadline of 31 January 2025. That may not come as a surprise, given the extra time allowed for online returns. That doesn't, however, mean you should wait until the last minute.

Here, we explain what you need to know about the paper tax return deadline and, if you miss it, outline six compelling reasons why you should consider filing online early.

When is the paper tax return deadline?

The deadline for filing paper returns is 31 October, but fewer people are choosing to post their self-assessments. HMRC figures show the number of paper returns has dropped by a third in the past five years – from 468,447 in the financial year 2020-21 to 312,000 in 2024-25.

The tax office no longer automatically sends out paper tax returns, although it does still post to people it has identified as being unable to file online. Most people, however, will have to either download and print the form or call HMRC on 0300 200 3310 to have one mailed to them.

Don't panic if you run out of time and miss the deadline, as you can still file online. But don't do both. Sending the paper forms off late will mean you will incur a penalty for late filing.

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6 reasons to file online early

Whether you missed the paper deadline or always intended to file your 2024-25 self-assessment online, getting organised now and submitting well ahead of time has lots of benefits.

1. More time to prepare

If you're new to filing a self-assessment tax return, you'll need to give yourself plenty of time to prepare.

Assuming you register by the deadline of 5 October, you will need to wait for your 10-digit Unique Taxpayer Reference (UTR) number to arrive. That can take up to 10 working days if you're in the UK or 21 days if you're abroad.

Once that's sorted, the next hurdle is to request an activation code for your account. That can take another 10 days to come through. If you're planning to file a paper return, you could easily miss the cut-off date at the end of this month.

If that happens, you'll still have until 31 January to file your return online, but this is the final deadline for both submitting the form and paying the bill. If you miss it, you could face a hefty fine, plus interest on top of whatever is owed.

With so many dates to think about, it's worth marking the main tax return deadlines in your calendar so you don't forget.

2. You can prevent costly mistakes

Doing everything in a last-minute panic is more likely to lead to errors – mistakes which HMRC may fine you for. 

The penalties imposed are based on the amount of tax you owe, and depend on the kind of error HMRC deems you to have made:

• If you have taken reasonable care to fill in your return correctly, you'll have no penalty to pay.
• If you haven't taken reasonable care, the penalty will be between 0% and 30% of the extra tax owing.
• If you have deliberately underestimated your tax, the penalty is between 20% and 70%.
• If you have deliberately underestimated your tax and attempted to conceal the fact, the penalty will be between 30% and 100%.

If you realise you made a mistake, you can correct your tax return for up to a year after the filing deadline via the HMRC online portal or via your software provider. After this timeframe, you'll need to write to HMRC to explain the circumstances and request a change.

For paper tax returns, you'll need to download a new return and mail it to HMRC with 'Amended' written on each corrected page.

3. Easier to budget

If you file your tax return and pay the bill now, you'll know exactly how much money you've got for the rest of the financial year, and you should be in a stronger financial position should the unexpected happen.

If you've been hit by changes to dividend tax and capital gains tax – or find yourself moving into a higher income tax band – then you'll have more time to budget for that as well. The best way to make sure you can afford your future tax bill is to put money aside each month as you earn it. 

You could consider starting a budget payment plan with HMRC to help you stay on track. You'll be in control of how much you want to pay each month and can settle any difference when it comes to deadline day. You can find out how to set one up for next year on the HMRC website.

• Find out more: how much tax you pay

4. Avoid late penalties

There are a number of deadlines to watch out for and penalties for missing them. So getting your return done with plenty of time to spare will save you stress and money.

Here are the main dates to put in your calendar.

• Registration, by 5 October 
• Paper returns, by 31 October
• Online returns, by 31 January
• Payment, by 31 January

Take a look at our guide for a full list of fines for tardy taxpayers. You can also calculate potential penalties using the gov.uk calculator.

5. You can prepare for payments on account

If you owe more than £1,000, and you aren't paying 80% or more of your tax bill via PAYE, you'll need to make what's known as payments on account. These are payable on 31 January and 31 July, and each one covers half your estimated tax bill for the current tax year. The estimate is based on your tax bill for the previous year. 

Spreading your bill throughout the year is intended to make tax easier to pay, but if you're new to the system, that first instalment might come as a shock. Filing and paying well before the January deadline gives you more time to get ready for the second payment in the summer.

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

6. Processing times won't catch you out

There are several ways to settle your bill, but pay attention to the time it takes to process the payment. 

To get the payment to its destination on the same or next day, use Faster Payment or CHAPS online, app and telephone banking services, debit card or business credit card.

Faster Payments is the system most banks use for everyday online transfers, while CHAPS is designed for larger, guaranteed same-day payments (although your bank may charge a fee).

Paying by Bacs (a system often used for payroll and direct debits) or by cheque in the post can take around three days – but cheques could take much longer to arrive if there are postal delays. 

HMRC doesn't take personal credit card payments for tax, and you can no longer pay your tax bill at the Post Office. 

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