If you receive a notification that you need to complete a Self Assessment tax return, the law says you have to file a return, whether or not you have any income for the year.
There are various charges (called penalties) that you have to pay if the return is not filed by the due date, or the tax is paid late.
Getting a tax return withdrawn
If you get a letter or email that says you need to complete a tax return, but you don’t think you need to, you can ask HMRC to withdraw the return.
There are only limited circumstances in which HMRC will withdraw a return, and the application must be made within two years of the end of the tax year (for example, 5 April 2026 for the tax year that ends 5 April 2024).
HMRC may withdraw the return if they agree that it was issued in error, and you have no income that needs to be reported on a return. This could either be because:
- you had no income in the year, or
- all your income was fully taxed already under PAYE.
HMRC will not withdraw the return if you had income, but don’t owe any tax. For example, if your business made a loss, you would still have to complete the return, even though you haven’t made any profit to pay tax on.
To ask for a return to be withdrawn call HMRC on 0300 200 3310.
What if I register late for Self Assessment?
If you register for Self Assessment after the deadline of 31 October, the deadline is extended to three months after you get a letter from HMRC saying you need to file a tax return. The new due date will be shown on the letter or email.
For example, if you register for Self Assessment on 7 November and HMRC send you a letter on 7 December, you will have three months (until 7 March) to complete your return.
However, don’t forget that you may have to pay interest on any tax you owe from 31 January. This is the case even if you file your return after this date.
What are the tax return deadlines?
A tax return must be filed by:
- Paper return: 31 October following the end of the tax year. For example, 31 October 2026 for the 2025/26 tax year.
- Online returns: 31stJanuary following the end of the tax year. For example, 31st January 2027 for the 2025/26 tax year.
If the return is not filed by the due date, the HMRC system automatically issues penalties for late filing.
What are the penalties for filing a tax return late?
There are different types of penalties, depending on if and when the tax return is filed.
These penalties can quickly grow. For example, if the return is over 12 months late, penalties could be as much as £1,600, with interest added to late payment of the penalties.
These are the penalties:
- If your tax return is late, you will be charged an automatic penalty of £100, even if you do not owe any tax.
- If the return has not been filed within three months of the deadline, a further daily penalty of £10 per day is charged. This goes up to a maximum of £900.
- If the return has not been filed within six months of the deadline, another penalty of £300 or 5% of the tax owing is charged.
- If the return has not been filed within 12 months of the deadline, another penalty of £300 or 5% of the tax due is charged.
So, for example, if you do not file your tax return within 12 months of the deadline, you would pay at least £1,600. This would be made up of:
- First £100 automatic penalty
- £900 in daily penalties, at £10 a day
- £300
- Another £300
These are basic penalties. Charges may be higher if the tax owed is significant.
Can I appeal a late filing penalty?
In exceptional cases, HMRC will consider appeals against penalties for being late with your tax return.
They don’t normally consider appeals until the tax return has been filed, so you must file the return before you make an appeal. You have to do this even if your tax return shows that you don’t owe any tax.
Penalties can be cancelled only if you have a “reasonable excuse” for filing late.
How do I appeal a late filing penalty?
Appeals must be in writing on form SA370. The appeal needs to be made within 30 days of the penalty notice being issued. HMRC might consider an appeal after the 30 days if there is a good reason for the delay.
What if my appeal is rejected?
If HMRC rejects your appeal, you can ask for a review. This will be carried out by an HMRC officer who has not been involved in your tax affairs before.
If you didn’t include all the information you meant to in your appeal against the penalties, you may be able to include this in the review.
Appeals to the First Tier Tribunal
If HMRC review your appeal but still reject it, you can appeal to the First Tier Tribunals (Tax). This can be done either at an in-person hearing or on paper.
Get more information about appealing to the First Tier Tribunal.
What counts as a “reasonable excuse”?
HMRC and the Tribunal can only accept an appeal if they consider that you have a “reasonable excuse”.
The reasonable excuse must continue throughout the whole period between the missed filing date and the date the return is actually filed. If you did not file the return as soon as possible after you became able to, the penalties will not be cancelled.
HMRC’s view of what is a “reasonable excuse” is narrow. Find out about what they count as a reasonable excuse.
The Tribunal might sometimes take a wider view of what is reasonable. However, they need clear evidence that there was a valid reason for the return not being filed on time.
What tax do I pay if I submit my tax return late?
If you file a paper return after the due date, HMRC will work out how much tax you owe. However, the tax will still be owed from the original date (31 January), as if you had submitted your tax return on time. That means that your tax might already be late by the time you find out how much you owe. Interest will be charged on any tax that is paid late.
Do I pay tax if I don’t file a return?
If you don’t file a return by the deadline, HMRC may make a formal estimate of the tax that they think you owe, called a determination.
The tax shown in the determination is due straight away. Interested will be added if your payment is late.
To challenge or reduce the estimated tax, you need to file a return for that year. This must be done within three years of the 31 January online filing date.
Once the determination is made, HMRC are entitled to collect the tax that’s owed, including taking recovery proceedings and even asking the court to make the debtor bankrupt.
What if I pay my tax late?
HMRC will charge interest on any tax that is paid late. This interest will be charged at their published rate, which is 4% above the Bank of England base rate.
There are also penalties for late payment. These are:
- 5% of the tax due if the tax is unpaid after 30 days.
- Another 5% if the tax is unpaid after six months.
- Another 5% if the tax is unpaid after 12 months.