Mailing Tax Forms to HMRC in the UK

• Most Self Assessment is done online, but paper returns and certain documents still go to HMRC by post.
• The paper Self Assessment deadline (31 October) is earlier than the online deadline (31 January) — don't mix them up.
• Always keep proof of the date you posted anything with a deadline.
• PostPal lets you post documents to HMRC online for a flat £4 — no printer or Post Office trip.
• Always confirm the correct HMRC address on GOV.UK before posting, as addresses vary by form.

HMRC has pushed most services online, and for good reason — filing your Self Assessment digitally is faster and gives you until 31 January. But paper still has its place: paper Self Assessment returns, certain claims and appeals, and supporting documents that can't be submitted online.

If you do need to post something to HMRC, this guide covers how it works and what to watch for.

For Self Assessment, the deadline depends on how you file:

• Paper return: 31 October following the end of the tax year.
• Online return: 31 January following the end of the tax year.
• Paying tax owed: 31 January.

Because the paper deadline is three months earlier, posting a paper return late can mean a penalty even if you'd have been fine online. If a deadline is close, keep proof of when you posted it.

HMRC uses different addresses for different forms, and many now route through a central BX9 postcode (for example, "Self Assessment, HM Revenue and Customs, BX9 1AS"). Always check the exact address on the relevant GOV.UK page or on the form itself before posting.

To send by post with PostPal:

1. Upload your completed form or write a covering letter online.
2. Attach any supporting documents (up to 5 files).
3. Enter the HMRC address exactly as shown on GOV.UK.
4. Pay £4 and we print and post it via Royal Mail.

For anything with a deadline, a record of the posting date matters if a dispute ever arises. PostPal emails you a confirmation of posting for every letter. For more on protecting yourself, see how to keep proof you sent an important letter.

Disclaimer: This article is general information, not tax advice. Always confirm current deadlines and addresses on GOV.UK, and speak to an accountant if you're unsure.

Ready to post to HMRC? Send your documents online.