HMRC letter codes · Self Assessment (SA)
SA800Partnership tax return
Last reviewed 14 October 2026 · How Tax Letters checks its facts
In short
GOV.UK's tax return forms page lists the SA800 form, including supplementary pages, as the form for a partnership tax return.
“There are special forms if you’re sending a tax return for a business partnership or non-resident company, or if you’re a trustee. … Partnership SA800 form, including supplementary pages”
GOV.UK: Self Assessment tax return forms · checked 14 October 2026
Information, not advice: this page reports what HMRC, GOV.UK and the bodies named publish about SA800. Each fact has its source and the day it was checked beside it.
What it is
GOV.UK says to use form SA800 if the only income for the return period was trading and professional income, and taxed interest and alternative finance receipts from banks and building societies.
“Use form SA800 if the only income for the return period was: … trading and professional income … taxed interest and alternative finance receipts from banks and building societies”
GOV.UK: Self Assessment: Partnership Tax Return (SA800) · checked 14 October 2026
What it asks
GOV.UK says to include any relevant supplementary pages with your SA800 Partnership Tax Return.
“Include any relevant supplementary pages with your SA800 Partnership Tax Return.”
GOV.UK: Self Assessment: Partnership Tax Return (SA800) · checked 14 October 2026
How to send it or apply
GOV.UK's SA800 page says you can send this tax return online instead of downloading the form.
“You can send this tax return online instead of downloading the form.”
GOV.UK: Self Assessment: Partnership Tax Return (SA800) · checked 14 October 2026
Free help and HMRC contacts
For Self Assessment queries about returns, payments, replacements or notices, GOV.UK's general enquiries page gives the number 0300 200 3310 and links to information about call charges. The page does not name SA800.
“Call HMRC if you have a query about: … your Self Assessment returns, payments, replacements or notices … Telephone: 0300 200 3310 … Find out about call charges”
GOV.UK: Self Assessment: general enquiries · checked 14 October 2026
Free help first
These routes are described by GOV.UK, TaxAid and Citizens Advice themselves.
- HMRC's extra supportHMRC offers extra support if your health condition or personal circumstances make it difficult to contact HMRC, for example a mental health condition, financial hardship or being treated in hospital.
- Someone to deal with HMRC for youYou can authorise a friend, relative or voluntary organisation to talk to HMRC for you and help you fill in forms.
- TaxAidTaxAid helps people with tax problems who cannot pay for advice. Tax Help for Older People merged with TaxAid in July 2025.
- Citizens AdviceCitizens Advice gives confidential advice online, over the phone and in person, for free.
- GOV.UK: Self Assessment tax return forms (checked 14 Oct 2026)
- GOV.UK: Self Assessment: Partnership Tax Return (SA800) (checked 14 Oct 2026)
- GOV.UK: Self Assessment: general enquiries (checked 14 Oct 2026)
- GOV.UK: Get help from HMRC if you need extra support (checked 7 Oct 2026)
- GOV.UK: Appoint someone to deal with HMRC on your behalf (checked 7 Oct 2026)
- TaxAid: About us (checked 8 Oct 2026)
- Citizens Advice: About us (checked 7 Oct 2026)