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What an HMRC Self Assessment “notice to file” means (and late filing)

HMRC often sends a letter saying you must send a Self Assessment tax return — a notice to file. This page explains the usual pattern in the UK. Always use the dates and figures printed on your letter or in your Personal Tax Account.

General information only — not legal or financial advice, and not a substitute for an accountant. Tax rules change. For free help, contact Citizens Advice or read GOV.UK — Self Assessment tax returns and GOV.UK — Self Assessment penalties.

In plain English

A notice to file means HMRC expects you to complete a Self Assessment return for a named tax year. It does not automatically mean you owe tax or that you have done something wrong. Millions of people get these letters every year (for example if they are self-employed, have untaxed income, or HMRC needs a return for another reason).

If you file late, HMRC usually charges an automatic £100 late filing penalty, with further penalties if the return stays outstanding. Paying tax late is separate from filing late — both can create charges. Check your letter carefully for which applies.

Typical deadlines

1. Online filing: commonly 31 January after the end of the tax year (tax years run 6 April–5 April). Your letter should state the filing date.
2. Paper filing: the paper deadline is earlier than the online deadline — use GOV.UK / your letter, not this summary alone.
3. Payment of tax due: often also tied to 31 January for the balancing payment — again, confirm on GOV.UK and your statement.
4. Late filing: a £100 penalty is commonly charged soon after the online deadline is missed; longer delays can mean daily and percentage-based penalties. See GOV.UK penalties guidance for the current ladder.

What to do next

• Find your UTR, National Insurance number, tax year and filing date on the letter.
• Sign in to your HMRC Personal Tax Account / Self Assessment and confirm what HMRC shows.
• File online before the deadline if you can. Register for Self Assessment first if you are new to it.
• If you have already filed, keep your submission receipt and check the letter is not a duplicate or a scam.
• If you cannot pay a tax bill, look up HMRC payment options / Time to Pay on GOV.UK — filing on time still matters.
• Watch for scams: HMRC does not send texts or emails with “claim your refund” links.

Common mistakes

• Ignoring the letter because “I already paid PAYE” — you may still need to file.
• Missing the paper vs online deadline difference.
• Assuming a late filing penalty means you must also pay a large tax bill immediately without checking the breakdown.
• Replying to unexpected emails that look like HMRC instead of using official GOV.UK contact routes.

Free help

• GOV.UK — Self Assessment tax returns
• GOV.UK — Understand Self Assessment penalties
• GOV.UK — Contact HMRC
• Citizens Advice

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