HMRC letter codes · One-to-many letters
WS1NSAMMLetter saying a Self Assessment return may be due, first of three
Published by its source on 27 October 2025. A date in the letter that has passed stays passed: what a passed date means.
Last reviewed 14 October 2026 · How Tax Letters checks its facts
In short
HMRC's letter WS1NSAMM is headed “Check your income for the tax year 2022 to 2023”.
“WS1NSAMM … Check your income for the tax year 2022 to 2023”
ICAEW: HMRC letter WS1NSAMM, as published with its tax news item · checked 14 October 2026
Information, not advice: this page reports what HMRC, GOV.UK and the bodies named publish about WS1NSAMM. Each fact has its source and the day it was checked beside it.
When HMRC sends it
ICAEW said, in its news item with HMRC's letter WS1NSAMM, that a taxpayer would receive one of three letters depending on their position, and that this is letter one, for a taxpayer who had not registered for ITSA (income tax self assessment).
“an income tax self assessment (ITSA) tax return … The taxpayer will receive one of three letters depending on whether: … they have not registered for ITSA (letter one)”
ICAEW: Wealthy taxpayers asked to check if tax return required · checked 14 October 2026
HMRC's letter WS1NSAMM says HMRC's records show that, based on the reader's income for the tax year, they may need to register for Self Assessment and submit a tax return.
“Our records show that based on your income for the above tax year, you may need to register for Self Assessment and submit a tax return.”
ICAEW: HMRC letter WS1NSAMM, as published with its tax news item · checked 14 October 2026
What it asks
HMRC's letter WS1NSAMM asks the reader to check whether they need to register for Self Assessment and submit a tax return for the tax year 2022 to 2023.
“Check if you need to register for Self Assessment and submit a tax return for the tax year 2022 to 2023.”
ICAEW: HMRC letter WS1NSAMM, as published with its tax news item · checked 14 October 2026
Free help and HMRC contacts
HMRC's letter WS1NSAMM points to GOV.UK, search “Check if you need to send a Self Assessment tax return”.
“Go to GOV.UK and search ‘Check if you need to send a Self Assessment tax return’.”
ICAEW: HMRC letter WS1NSAMM, as published with its tax news item · checked 14 October 2026
HMRC's letter WS1NSAMM gives the phone number 03000 516640 for a reader who wants to speak to HMRC about the letter.
“If you want to speak to us about this letter, please call us on 03000 516640”
ICAEW: HMRC letter WS1NSAMM, as published with its tax news item · 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.
- ICAEW: HMRC letter WS1NSAMM, as published with its tax news item (checked 14 Oct 2026)
- ICAEW: Wealthy taxpayers asked to check if tax return required (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)