HMRC self assessment letters full

Written by Oroni Chowdhury · Published: October 2026 · Last reviewed: October 2026 · Applies to the 2026/27 tax year

Few things unsettle a taxpayer like an unexpected envelope from HMRC, and the official language rarely makes clear whether you owe money, must file, or can stop worrying. HMRC self-assessment letters fall into a small number of types, though. Work out which one you have and the next step, along with its deadline, usually becomes obvious.

Below, each letter is grouped by purpose for 2026/27, with what it asks of you and the slip-ups that most often turn a routine letter into a bill.

HMRC Self-Assessment Letters at a Glance

Find your letter in the left-hand column, then read across for the action and the time allowed. Later sections go into each type.

Paper letter or online account?

Some HMRC correspondence and tax details may also be available in your online account. Check your account regularly if you use paperless communications, but follow the instructions and deadline on the original notice. If the details do not match, contact HMRC using contact information verified through GOV.UK.

Self Assessment Letter or Something Else?

A few HMRC letters resemble Self Assessment post but run on separate rules:

• PA302 Simple Assessment: a bill HMRC calculates for you, with no return involved.
• P800: a year-end PAYE calculation showing tax overpaid or underpaid.
• P2 coding notice: a new tax code for wages or pension.

None of these needs a tax return, so deal with each under its own guidance.

Notice to File a Tax Return

The notice to file carries more weight than any other of the HMRC self-assessment letters. It places you under a legal obligation to submit a return for the year it names, and a missed deadline can lead to penalties even if the return would show nothing to pay.

Why you got one

Common triggers include registering as self-employed, starting to let a property, or answering yes to certain questions on last year’s return. HMRC also acts on information it receives from third parties. LITRG reported that in March 2026 around 120,000 people received notices for 2024/25 after bank data showed savings interest over £10,000.

If the notice arrives late

If HMRC issues a notice to file after 31 October following the end of the tax year, you will normally have three months from the date the notice is given to submit the return. Check the date on your notice carefully, as it may differ from the standard filing deadline. If the letter gives conflicting dates, confirm the correct deadline with HMRC rather than assuming the usual 31 January date applies.

This matters because HMRC self-assessment letters have not always been clear on the point: LITRG noted that some 2026 notices still mentioned a deadline that had already passed.

If you don’t think you need to file

Run GOV.UK’s check tool first. If it shows you are outside Self Assessment, let HMRC know you no longer need to send a return online, by phone or by post, without delay. HMRC has to review the request before 31 January, and contacting it too late can still result in a penalty.

Reminders and Penalty Letters

Reminders are the mildest HMRC self-assessment letters, sent around the deadline as a prompt. Penalty notices come next once a return or payment is overdue, and the amounts grow the longer it stays outstanding.

Late filing penalties

The amounts follow GOV.UK’s Self Assessment penalty rules. Under the standard late-filing penalty structure, a return that remains outstanding for 12 months can attract £1,600 or more in filing penalties, depending on the circumstances. This is separate from the tax owed, late-payment penalties and interest.

Late payment penalties and interest

Tax paid late picks up a 5% penalty on the unpaid amount at 30 days, at six months and at 12 months, and interest accrues throughout. A penalty notice is itself payable within 30 days of its date. For the wider picture, read our guide to HMRC penalties.

How to appeal

Penalty-related HMRC self-assessment letters explain how to challenge them. A reasonable excuse, such as a serious illness or the death of a close relative near the deadline, can support an appeal. According to GOV.UK, you usually have 30 days from when the penalty was issued. Follow the form or instructions supplied, or write to HMRC setting out:

• the reason the return or payment was late, with dates;
• your name and Unique Taxpayer Reference;
• when you tried to file and any error shown, if a technical fault stopped you.

If the appeal is refused, you can request a review or take it to the tax tribunal.

HMRC Self-Assessment Letters About Your Bill

Once your return is in, the HMRC self-assessment letters that follow deal with payment: how much, by when, and why the total can exceed the tax shown on your return.

Your Self Assessment statement

People misread statements more often than any other HMRC self-assessment letters. A statement sets out the charges on your account, the payments HMRC has received and the next due dates. Check it line by line against your tax calculation. If a payment has not been credited, send HMRC the date, the amount and the payment reference you used.

Payment on account reminders

Payments on account are advance instalments towards the following year’s bill. GOV.UK explains that each instalment equals half of last year’s tax, payable by 31 January and 31 July. They do not apply if last year’s bill was below £1,000, or if over 80% of your tax was already collected at source, through a tax code for instance.

You can reduce payments on account through your online account or on form SA303. Set them too low, though, and HMRC will charge interest on the difference once the final figure is known.

SA302 tax calculation

Mortgage lenders often want an SA302 together with a tax year overview. GOV.UK says you can print both from your HMRC online account once 72 hours have passed since filing, or print the calculation from your filing software. Confirm first that your lender accepts copies you print yourself.

Repayment check letters

When a return claims money back, HMRC sometimes writes to verify the claim before paying. These letters quote your UTR and set a deadline for replying, so send the information requested by the date shown. GOV.UK warns that a repayment letter asking you to email evidence to an address that does not end in hmrc.gov.uk is not genuine.

Compliance Checks, Nudge Letters and MTD Letters

Treat these HMRC self-assessment letters with extra care, since your answers can shape any penalty later on.

• Compliance check: HMRC is examining a return and may ask to see records. Take advice before you answer, and reply within the time given.
• Nudge letter: HMRC has information, perhaps from banks, online platforms or overseas tax authorities, that points to income missing from your returns. Review your figures and put any mistake right instead of setting the letter aside.
• Making Tax Digital letter: HMRC is telling you that your income brings you into Making Tax Digital for Income Tax.

From 6 April 2026, Making Tax Digital for Income Tax generally applies to eligible sole traders and landlords whose combined qualifying income from self-employment and property exceeded £50,000 in 2024/25. The threshold is due to fall to over £30,000 from April 2027, based on 2025/26 qualifying income.

Qualifying income means gross income before expenses, not profit, and exemptions may apply. Those within the rules must use compatible software to keep digital records, send quarterly updates and submit their tax return. ICAEW reported that HMRC wrote to a further group in scope in June 2026.

Is the Letter Really From HMRC?

Scammers imitate HMRC self-assessment letters, particularly as the January deadline approaches. Before paying anything or sending information, take three steps:

1. Go to GOV.UK, sign in to your HMRC online account and look for the same charge or request.
2. Check that the letter shows your UTR and a clear deadline. A request to email documents to an address that does not end in hmrc.gov.uk is a fake.
3. Compare it with HMRC’s own list of genuine letters currently being sent, and call numbers taken from GOV.UK rather than from the letter if you have doubts.

Fake texts, emails and phone calls are covered in this Self Assessment scam warning guide.

Common Mistakes With Self Assessment Letters

Trouble with HMRC self-assessment letters usually comes down to timing, not the tax itself.

FAQs: HMRC Letters About Self Assessment

What letters does HMRC send for Self Assessment?

The main HMRC self-assessment letters are notices to file, filing reminders, penalty notices, statements, payment on account reminders, repayment checks, compliance check letters and confirmation that you can stop filing.

Why have I got a notice to file when I’m employed?

HMRC may have data showing other income, such as savings interest over £10,000, rental income or side earnings. If you think the notice is wrong, contact HMRC and explain before the deadline.

How long do I have to appeal a Self Assessment penalty?

Usually 30 days from the date the penalty was issued. A later appeal is possible, but you will need to explain the delay too.

Can HMRC cancel a notice to file?

Yes. If you show that you do not need to file, HMRC can withdraw the notice. Ask early, and well before 31 January.

Why is my January Self Assessment bill so high?

It is likely to include your first payment on account for the next tax year, equal to half of last year’s bill, on top of the balance for the year you have just filed.

Where is my UTR on an HMRC letter?

It is normally printed near the top, often labelled as your tax reference. It has 10 digits and is also shown in your HMRC online account.

Will HMRC email me instead of writing?

Only if you have opted for paperless contact, in which case HMRC emails to prompt you to check your online account. HMRC does not ask for bank details or payment by email.

Final Verdict: HMRC Self-Assessment Letters Explained

HMRC self-assessment letters each ask for one thing: file, pay, appeal, reply or note a change. Identify the letter, find the date on it and act within the time allowed. Check anything unexpected through your HMRC online account, and get help early with penalties or compliance checks.