| Authority | HM Revenue & Customs (HMRC), the UK's tax, payments and customs authority |
| Tax year | 6 April 2026 to 5 April 2027 |
| Registering for Self Assessment | by 5 October after the end of the tax year |
| Online return 2025/26 | by 31 January 2027, 23:59 |
| Payment | 31 January; payments on account 31 January and 31 July |
| Making Tax Digital | compulsory for sole traders and landlords over £50,000 since 6 April 2026 |
| Updated | November 2026 |
What is HMRC?
HMRC stands for HM Revenue & Customs. It describes itself as the UK's tax, payments and customs authority. It is a non-ministerial department, a government body without a minister of its own at the top. For you as an individual, HMRC is simply the tax office: income tax, National Insurance and capital gains tax all run through it.
Do not confuse HMRC with HM Treasury. The Treasury is the finance ministry, which makes tax policy and presents the Budget. HMRC applies the law, sends the letters and collects. If an email in the Treasury's name promises a refund, that is a warning sign; more on that below.
The UK tax year does not run from January to December but from 6 April to 5 April. The current tax year 2026/27 began on 6 April 2026 and ends on 5 April 2027. Move in the summer and your tax year starts in the middle of your home country's calendar year.
Employees pay through PAYE (Pay As You Earn): the employer or pension payer deducts income tax and National Insurance before the money reaches your account. Your tax code tells them how much. If all you have is a salary, you often do not file a return at all. Whether you are taxable in the UK in the first place is decided by the statutory residence test, not by your visa.
Self Assessment: who has to file a return
Self Assessment is how HMRC collects income tax from everyone whose income is not already taxed at source. You need a return for the past tax year if, among other things:
- you earned more than £1,000 as a self-employed sole trader, counted before expenses
- you owe capital gains tax, for example after selling shares or a second home
- you had more than £2,500 of other untaxed income, for example from letting
- you have interest, dividends or foreign income not already covered by PAYE
- HMRC asks you in writing: then you must file, even if you think you owe nothing
The deadlines for the 2025/26 tax year
New to Self Assessment? Then you register first, by 5 October after the end of the tax year. Your tax reference, the UTR, then arrives by post; what it looks like and what you need it for is in NINO and UTR. If you register after 5 October, HMRC gives you a filing deadline of three months from the date of its letter. Payment is still due on 31 January.
| What | Deadline | Note |
|---|---|---|
| Registration (first time or after a year out) | 5 October 2026 | register late and fail to pay by 31 January and you risk a failure-to-notify penalty |
| Paper return | 31 October 2026, 23:59 | must have reached HMRC |
| Online return, collected through your tax code | 30 December 2026, 23:59 | only if the amount is to be collected through PAYE |
| Online return | 31 January 2027, 23:59 | can be filed from 6 April 2026 |
| Payment (balance and first payment on account) | 31 January 2027 | penalties and interest after that |
| Second payment on account | 31 July 2027 | only if payments on account apply |
| Amending the return | 31 January 2028 | 12 months after the filing deadline |
GOV.UK: Self Assessment tax returns, November 2026
Paying, payments on account and penalties
HMRC works out the tax from your return. From the second year, payments on account usually come in: two advance payments towards the next year, each half of last year's tax, due on 31 January and 31 July. You are exempt if you owed less than £1,000 last year or more than 80% was already paid outside Self Assessment, say through your tax code. If the payments on account fall short, a balancing payment follows on 31 January.
That is exactly what catches many people in their second year after the move: on 31 January the balance for the old year and the first payment on account for the new year fall due together. Know it, and you put money aside in time.
Penalties are mechanical. File late and it costs £100 at once, after three months £10 a day up to £900, and after six and twelve months a further 5% of the tax or £300 each time, whichever is higher. Pay late and you pay another 5% of the unpaid tax after 30 days, after six months and after twelve months, plus interest. If you have a reasonable excuse, you can appeal.
More is announced: from 6 April 2027 a new late filing and late payment penalty system is to apply to Self Assessment taxpayers not within Making Tax Digital too (Budget 2025). And from April 2029 the government wants taxpayers with payments on account to pay more regularly during the year (Budget 2026, details still being worked out).
Digital: the HMRC app, the personal tax account and Making Tax Digital
The HMRC app exists for iOS and Android. It shows your tax code, your UTR, what you owe and your National Insurance number, which you can even save to Apple or Google Wallet. In a browser, the personal tax account does the same and more: tax estimate, Self Assessment, refunds, change of address. Both are worth setting up from day one.
Making Tax Digital for Income Tax is the biggest change in years. It affects sole traders and landlords registered for Self Assessment whose combined self-employment and property income passes a threshold: compulsory above £50,000 since 6 April 2026, above £30,000 from 6 April 2027, above £20,000 from 6 April 2028. The test year is always the tax year two years before. You then keep digital records in software and send quarterly updates; the annual return stays.
For 2026/27 HMRC waives penalties for late quarterly updates, and the same applies in 2027/28 for those joining in April 2027. Of interest to landlords living abroad: under Budget 2026 non-residents are expected to be exempt from Making Tax Digital until further notice, with the regulations due before April 2027. If you let a flat in England from abroad, also read our piece on the Non-Resident Landlord Scheme.
Spotting an HMRC scam: the warning signs
Fake HMRC emails, texts and calls are part of everyday life in the UK, and the refund trick is the oldest of all. HMRC lists the warning signs itself. Be careful if a message:
- is urgent, threatening or completely unexpected
- asks for bank details or other personal information
- tells you to transfer money
- offers a refund, a tax rebate or a grant
- threatens arrest or announces legal action in a voicemail: HMRC never does that
- asks for payment in vouchers or gift cards: HMRC never does that either
- offers a refund through social media or writes to you on WhatsApp, apart from one-way reminders on the official government channel
Forward suspicious texts to 60599 and suspicious emails to phishing@hmrc.gov.uk, then delete them. HMRC does send texts itself, but a QR code or link from HMRC never leads to a page asking for personal details. If you have already lost money, report it to Report Fraud, or in Scotland to Police Scotland on 101. When in doubt, click nothing and log in yourself through the app or your personal tax account.
Frequently asked questions about HMRC
Do I have to file a return as an employee in England?
Usually not. If you only have a salary, your employer deducts the tax through PAYE. You need a return if other income comes in, such as rent, capital gains or foreign income, or if HMRC asks you to file.
What is the difference between HMRC and HM Treasury?
HM Treasury is the finance ministry and presents the Budget. HMRC is the authority that collects tax. Letters about your tax always come from HMRC.
What is the HMRC list of reporting funds?
HMRC keeps a monthly updated list of offshore funds that have applied for and obtained reporting fund status. For non-UK funds you keep after the move, that status makes a difference to UK tax. What it means for your portfolio is in pensions and investments in the UK.
How do I recognise a genuine text from HMRC?
HMRC does text some customers, with links to GOV.UK or its webchat. But a genuine text never offers you a refund in exchange for bank or personal details. When in doubt, forward it to 60599 and check the app yourself.
For how long can I still amend a return?
Online or on paper until 12 months after the filing deadline, so for 2025/26 until 31 January 2028. After that only in writing to HMRC.
Sources: GOV.UK: HM Revenue & Customs; GOV.UK: Self Assessment tax returns; GOV.UK: Check how to register for Self Assessment; GOV.UK: Understand your Self Assessment tax bill, payments on account; GOV.UK: Find out if and when you need to use Making Tax Digital for Income Tax; GOV.UK: Download the HMRC app; GOV.UK: Identify tax scams by phone, text, email or social media; GOV.UK: Budget 2025, Overview of tax legislation and rates; GOV.UK: Budget 2026, Overview of tax legislation and rates
