HMRC Letter Help 2026: What Your HMRC Letter Means and What to Do Next
An HMRC envelope on the doormat is one of the few things that can ruin a whole day before you have even opened it. Most of the time it is far less serious than it feels. Some HMRC letters are simply telling you something. Some are giving you money back. A small number need action by a date — and those are the ones worth finding fast.
This guide explains the letters people actually get, in plain English, and what to do about each one.
The golden rule: HMRC does not text or email you a refund link
Before anything else, check the letter is real. HMRC states plainly that it will never notify you of a tax rebate, or ask for personal or payment details, by text message, and will only ever email about a rebate from an address ending in hmrc.gov.uk (GOV.UK, Report suspicious HMRC emails, texts, social media accounts and phone calls).
Real refunds come by post, or appear in your Personal Tax Account on GOV.UK. If a message says “you are owed £X, click here to claim within 24 hours”, it is a scam — no matter how convincing the logo is.
To report a fake:
- Suspicious text pretending to be HMRC: forward it to 60599 (charged at your network rate), then delete it.
- Suspicious email: forward it to phishing@hmrc.gov.uk, then delete it.
- Suspicious phone call: hang up. HMRC will not threaten you with arrest, and will not ask you to pay in gift cards or by bank transfer to a “safe account”.
If you are not sure, do not use any number or link in the message. Go to GOV.UK yourself and use the contact details there. Our scam checker will talk you through the tells.
The HMRC letters people actually get
P800 tax calculation, or Simple Assessment
A P800 tells you HMRC thinks you paid the wrong amount of tax for a tax year — usually because of a job change, more than one job or pension, or a benefit in kind. It will either say you are owed a refund or that you underpaid.
A Simple Assessment is similar, but it is a tax bill rather than a return: HMRC has worked out what you owe and is asking you to pay by a date on the letter, without you having to file a Self Assessment return.
What to do: check the figures. P800s are calculated from the information HMRC holds, and that information is sometimes wrong or out of date. Compare it with your P60, your P45 and your payslips. If it says you are owed money, claim it through the official route on GOV.UK — never through a link in a text. Our guide to tax refunds and wrong tax codes covers the whole process.
A tax code notice (a “coding notice”, form P2)
This tells you the tax code HMRC has given your employer or pension provider. It is not a bill. But an incorrect code is one of the most common reasons people quietly overpay tax all year, particularly after starting a new job or picking up a second one.
What to do: read what the code means and check the assumptions behind it (company car, untaxed income, an old expenses claim that is no longer relevant). If it looks wrong, tell HMRC — they change it and it feeds through to your next payslip. See what your tax code means.
A Self Assessment late-filing penalty
If you missed the 31 January online filing deadline, HMRC issues an automatic £100 penalty. That applies even if you have no tax to pay, or you paid your tax on time. If the return is still outstanding after three months, £10 a day can be charged for up to 90 days (a maximum of £900), with further penalties at 6 and 12 months of 5% of the tax due or £300, whichever is greater. Interest is charged separately on unpaid tax (GOV.UK, Self Assessment tax returns: Penalties).
What to do: file the return, even if you cannot pay the tax yet — the penalties for not filing keep growing on their own. You can appeal a penalty if you have a reasonable excuse, normally within 30 days of the penalty notice. See Self Assessment explained.
A tax credits overpayment letter
Tax credits have now closed and claimants have moved to Universal Credit, but overpayment letters are still landing. These say you were paid more than you were entitled to and HMRC wants it back — often years later.
What to do: do not just start paying if you think it is wrong. You can dispute an overpayment (there is a formal HMRC dispute process), and you can separately ask for an affordable repayment rate if the amount is right but you cannot pay it in one go. Free help from Citizens Advice is worth a call here.
“Check your records” or a compliance check
This is HMRC saying it wants to look at something — income you may not have declared, a claim it wants evidence for, or simply a nudge letter based on data it holds. It is not an accusation of fraud.
What to do: read carefully what is being asked and by when. Reply by the date given, even if the reply is “I need more time.” Silence turns a routine check into a bigger problem. If the amounts are significant, consider getting a qualified accountant or a free tax charity involved — TaxAid helps people on low incomes with tax problems.
The deadlines that actually bite
Most HMRC letters give you a date. Put it in your phone the moment you open the envelope. The ones that matter most:
- 31 January — the online Self Assessment filing deadline, and the date the tax for the previous tax year is due. Miss it and the £100 penalty is automatic.
- 31 July — the second payment on account, if you make them.
- 5 October — the deadline to register for Self Assessment if you have new untaxed income.
- 30 days — the usual window to appeal a penalty.
- The date printed on your letter — for a compliance check or Simple Assessment, this is the one that counts.
If you cannot pay: ask for Time to Pay
HMRC would rather have an agreed instalment plan than an unpaid bill. Their arrangement is called Time to Pay: you spread what you owe over monthly payments you can genuinely afford. Interest still runs, but the plan protects you from further collection action while you keep to it.
For many Self Assessment bills you can set a plan up yourself online through your HMRC account. If you cannot, phone them. Ring before the deadline if you can — it is a very different conversation from the one you have after the bill is already overdue.
- Self Assessment general enquiries: 0300 200 3310 (Monday to Friday, 8am to 6pm; closed on bank holidays).
- Self Assessment payment enquiries / payment plans: 0300 200 3820 (Monday to Friday, 8am to 6pm).
Be ready with your Unique Taxpayer Reference, the amount you owe, and honest figures for your income and outgoings. Ask for the agreement in writing.
If tax is only one of several debts, deal with priorities first. Free, independent debt advice is available from StepChange on 0800 138 1111 and from Citizens Advice — and it is worth the call before you agree to anything.
What to do in the next ten minutes
- Check the letter is genuine — and never click a link in a “tax refund” text or email.
- Find the date. Write it down.
- Work out which of the four things it is: information, a refund, a bill, or a request for a reply.
- If it is a bill you cannot pay, call HMRC and ask about Time to Pay before the date passes.
- If the letter still makes no sense, put it through our free letter decoder.
Opening it is the hardest part. The rest is just steps.
SortedUK is an independent, free service. We are not HMRC, not a tax adviser and not affiliated with any government body — and we will still point you to Citizens Advice, TaxAid or a qualified accountant when a human is the right next step. Nothing here is tax advice; final decisions on your tax always sit with HMRC. Penalty figures, contact numbers and reporting routes were verified in July 2026 against GOV.UK and HMRC.