Paper Tax Return Deadline 31 October: Is It Too Late?

If you send your Self Assessment return on paper, HMRC must have it by 31 October 2026. Here is what that deadline means, and what you can still do if you miss it.

Is it too late?

Not if you file online. The 31 October deadline only applies to paper returns. An online return for the 2025 to 2026 tax year is on time up to 11:59pm on 31 January 2027.

What you cannot do is send a paper return after 31 October and still be on time. GOV.UK says HMRC must receive a paper return by 11:59pm on 31 October 2026 "or you'll get a late filing penalty".

31 October 2026 is a Saturday. The deadline is when HMRC receives the form, not when you post it.

Paying through your tax code

If you are an employee or get a pension, HMRC can collect your Self Assessment bill through your PAYE tax code, so you don't pay it all in one go. All three of these must apply:

• you owe less than £3,000 (you cannot make a part payment to get under this)
• you already pay tax through PAYE, for example as an employee or on a company pension
• your paper return reached HMRC by 31 October, or you filed online by 30 December 2026

If all three apply, HMRC sets this up automatically, unless you asked it not to on your return. If you miss the date, you have to pay another way, by 31 January 2027.

Who sends a paper return?

Anyone can ask for a paper form. You can download form SA100 from GOV.UK or call HMRC and ask for one. Forms and supplementary pages for other kinds of income are on GOV.UK too.

Two groups have a different date: trustees of a registered pension scheme and non-resident companies. They must send a paper return, and HMRC must receive it by 31 January 2027. They cannot send a return online. Pension scheme trustees use form SA970.

Some returns can be sent online using commercial software, for example for a partnership, for a trust or estate, or if you lived abroad as a non-resident. GOV.UK lists the suppliers.

If you registered late

The 5 October deadline for telling HMRC you need to send a return has passed. If you register after 5 October 2026, HMRC sends you a letter or email with your own deadline for the return: 3 months from the date on it.

The tax you owe is still due by 31 January 2027. If you register after 5 October and don't pay your whole tax bill by 31 January, you may get a "failure to notify" penalty.

Signed up for Making Tax Digital?

If you use Making Tax Digital for Income Tax from 6 April 2026, the current penalties above still apply to your 2025 to 2026 return.

Made a mistake on your return?

You can correct a return within 12 months of the Self Assessment deadline, either online or by sending another paper return. Your bill is then updated, so you may have to pay more tax or be able to claim a refund.

Where to get help

HMRC Self Assessment helpline: 0300 200 3310 (from outside the UK: +44 161 931 9070). Monday to Friday, 8am to 6pm, closed on bank holidays.

Sources: GOV.UK: Self Assessment tax returns; Pay your Self Assessment tax bill; Penalties for Making Tax Digital for Income Tax; Appeal a Self Assessment penalty; Self Assessment: general enquiries. nibusinessinfo.co.uk (Northern Ireland).