Written by Hammad Rasool MAAT·AAT licensed accountant·Updated November 2026

What the notice means

HMRC sends a notice to file, usually marked SA316, each April or May to people it expects a tax return from: the self employed, landlords, company directors with untaxed income and others. You also get one after you register for Self Assessment for the first time.

The notice creates a legal duty to file. Thinking that you owe nothing does not cancel it. The return has to be sent, or HMRC has to agree to withdraw the notice.

The deadlines for the 2025/26 tax year

  • Paper return: HMRC must receive it by 11:59pm on 31 October 2026.
  • Online return: by 11:59pm on 31 January 2027.
  • Payment: the tax is due by 11:59pm on 31 January 2027.
  • To have the tax collected through your tax code: file online by 11:59pm on 30 December 2026.
  • Notice issued late: if HMRC writes or emails to tell you to file, the deadline is 3 months from the date on that letter or email.

What happens if you ignore it

The penalties for a late return build up quickly:

  • 1 day late: £100, even if there is no tax to pay.
  • 3 months late: £10 a day for up to 90 days, a maximum of £900.
  • 6 months late: 5% of the tax due or £300, whichever is greater.
  • 12 months late: another 5% or £300, whichever is greater.

Late payment brings separate penalties of 5% of the unpaid tax at 30 days, 6 months and 12 months, plus interest.

Key point: a return with no tax to pay can still cost £1,600 in late filing penalties over a year. If you have had an SA316, never assume it will go away on its own.

If you think you do not need to file

Circumstances change. You may have stopped self employment, sold the rental property or gone back to PAYE only. Use the GOV.UK tool to check whether you still need to send a return, then tell HMRC. If HMRC agrees, it will withdraw the notice and confirm this in writing. Until you have that confirmation, treat the deadline as live.

Example

Sana stopped freelancing in March 2025 and took a full time job. In April 2026 she received an SA316 for 2025/26. She had no untaxed income at all in that year. She told HMRC online, HMRC withdrew the notice, and no return or penalty arose. Had she ignored the letter, the £100 penalty would have been issued in February 2027.

What you need to file

Your Unique Taxpayer Reference, your Government Gateway login, and the figures: income and expenses for self employment or property, P60 or P45 if you were also employed, bank interest, dividends and pension contributions.

Common questions

I have no tax to pay. Do I still have to file?
Yes, if HMRC has sent you a notice to file and has not withdrawn it. The £100 late filing penalty applies even when no tax is due.
My SA316 arrived late in the year. What is my deadline?
If HMRC sent the notice late, the deadline is 3 months from the date on the letter or email.
Can HMRC cancel the notice?
Yes. If you no longer meet the criteria for Self Assessment, tell HMRC. If it agrees, it withdraws the notice and the duty to file falls away.
What if I already missed the deadline?
File as soon as you can to stop further penalties building up. If you had a reasonable excuse you can appeal, normally within 30 days of the penalty notice.

Checked against GOV.UK on 10 November 2026: Self Assessment deadlines, Self Assessment penalties, Check if you need to send a tax return.

About the author

Hammad Rasool MAAT is an AAT licensed accountant based in Bolton. TaxTune Accountants looks after sole traders, landlords, contractors and limited companies in Bolton, Wigan, Bury, Salford, Oldham, Stockport and Manchester, and online across the UK.