How to Post Tax Documents to HMRC in 2026

• Paper Self Assessment returns are due 31 October; online returns and payment are due 31 January.
• Many HMRC forms now use a central BX9 postal address — but it varies, so always check GOV.UK for your specific form.
• Keep proof of posting for anything with a deadline.
• PostPal posts your documents to HMRC for a flat £4 — no printer, ink, or Post Office queue.

Even in 2026, some HMRC dealings still happen on paper — paper Self Assessment returns, appeals, certain claims, and supporting documents. If that's you this year, here's how to get it posted correctly and on time.

For the tax year that ended 5 April, the Self Assessment deadlines are:

• Paper return: midnight on 31 October.
• Online return: midnight on 31 January.
• Balancing payment: 31 January.

If you're posting a paper return, remember the earlier October deadline. Leaving it to the last few days is risky — post it with time to spare and keep your confirmation of posting.

HMRC has consolidated much of its post to a single BX9 postcode, with the specific line depending on what you're sending — for example, "Self Assessment, HM Revenue and Customs, BX9 1AS". Other services (PAYE, VAT, appeals) use different addresses.

There is no single address for everything, so always check the GOV.UK page for your specific form or letter, or the address printed on the form, before you post.

With PostPal you can send it without leaving your desk:

1. Upload your completed form or write a covering letter.
2. Attach supporting documents (up to 5 files, no extra charge).
3. Enter the HMRC address from GOV.UK.
4. Pay £4 — printing, envelope, and Royal Mail postage included.

We post it the next business day and email you a confirmation.

Disclaimer: This is general information, not tax advice. Confirm current deadlines and addresses on GOV.UK. Post your tax documents now.