HMRC has launched an improved Self Assessment registration service that puts a new filer’s Unique Taxpayer Reference (UTR) online within 72 hours, rather than up to 15 days by post. The change, announced in an HMRC press release on 9 September 2026, matters ahead of 31 January 2027: a tax return, and any refund claimed through it, can’t be started without a UTR.
The key points at a glance:
- UTR timing: within 72 hours in the online account, against up to 15 days for a posted letter, according to HMRC.
- Who registers: HMRC’s list includes people newly self-employed earning more than £1,000 gross, new business partners and anyone with untaxed income above £2,500.
- Deadlines: first-time filers for the 2025 to 2026 tax year had to register by 5 October 2026; any tax owed is due by 31 January 2027.
- Leaving Self Assessment: people who no longer need to file must tell HMRC, and should keep meeting their obligations until HMRC confirms.
What has changed in Self Assessment registration
Registration for people new to Self Assessment now runs through the Personal Tax Account. HMRC figures show Self Assessment registrations topped 640,000 in the year to 31 March 2026.
Myrtle Lloyd, HMRC’s Chief Customer Officer, said: “Registering is quicker and easier than ever.”
The rebuilt service offers:
- forms already filled in with details HMRC holds about the customer
- links to online help during registration
- the option to save progress and come back later without losing anything entered
- a text or email confirming that registration is complete
For anyone who expects registration to mean waiting for a letter, that is no longer how the new service works: the UTR is issued to the online account instead.
Government Gateway and GOV.UK One Login details both work for setting up a Personal Tax Account. The online route serves individual customers only; agents registering clients still follow the existing processes, which include forms CWF1 and SA1.
Who needs to register
HMRC’s full list of reasons for sending a tax return is on GOV.UK, and the department highlights several groups.
They include people who became self-employed and earned more than £1,000 gross, new partners in a business partnership, and anyone who received over £2,500 of untaxed income.
HMRC’s trading allowance guidance says gross income of £1,000 or less in a tax year, from sources such as self-employment or casual work, does not need reporting to HMRC. The allowance has exceptions, including income from a partnership.
People whose income stays within it can still register to make voluntary Class 2 National Insurance payments, which HMRC says helps protect entitlement to the State Pension and certain benefits.
Anyone already registered who did not file for the 2024 to 2025 tax year may need to reactivate their account to file for 2025 to 2026.
HMRC’s free online checker on GOV.UK is designed for those unsure whether they need to file a tax return at all.
The 5 October registration date has passed
First-time filers had until 5 October 2026 to register for the 2025 to 2026 tax year. The same date applied to people returning to Self Assessment after not needing to file for 2024 to 2025.
According to GOV.UK’s Self Assessment deadlines guidance, anyone registering after 5 October 2026 is sent a letter or email setting a filing deadline three months from its date. Payment of any tax owed remains due by 11:59pm on 31 January 2027.
For people who registered in time, the online return is also due by 11:59pm on 31 January 2027.
Late registration can lead to a penalty, but not a flat fine. HMRC’s failure-to-notify factsheet, CC/FS11, says the penalty is worked out as a percentage of the tax left unpaid because HMRC was not told in time, so the amount depends on what is owed.
Where the failure was not deliberate and is disclosed unprompted within 12 months of the tax becoming due, the penalty range starts at 0%.
HMRC’s guidance adds that no penalty is charged where there is a reasonable excuse, the failure was not deliberate and HMRC was told without unreasonable delay once the excuse ended.
Stopping Self Assessment: tell HMRC first
Someone who has stopped needing to file still has a step to take. They must tell HMRC as soon as possible, and should keep meeting their Self Assessment obligations until HMRC confirms the change.
If HMRC is not told, the press release says it then expects a return and issues a penalty for non-submission. Telling HMRC early matters, because each request takes time to review before the 31 January deadline.
GOV.UK lists stopping self-employment, no longer renting out property and no longer paying the High Income Child Benefit Charge as examples of why a return might no longer be needed.
HMRC has an online service for telling it, and people who cannot use it can phone or write instead.
Still need to register? What to do now
If you still need to register for Self Assessment and have income to declare for 2025 to 2026, these steps may help.
Steps to take now
- Check whether you need to file. HMRC’s free checker starts by asking whether you worked for yourself last tax year, and does not send your details to HMRC.
- Register through your Personal Tax Account. Sign in with either Government Gateway or GOV.UK One Login. If you missed 5 October, register anyway: telling HMRC sooner is likely to keep any penalty lower.
- Keep your confirmation. Save the email or text sent when registration is complete, then look for your UTR in your online account: HMRC says it arrives there within 72 hours.
- Note your deadlines. If you registered after 5 October 2026, check HMRC’s letter or email for your filing date, and plan to pay any tax owed by 31 January 2027.
- Tell HMRC once you no longer need to file, and keep meeting your obligations until it confirms.
- Check whether you are owed money. Once you are set up, your return may show you have paid too much tax, in which case a refund could be due.
Tax Rebate Services’ free guide to registering for Self Assessment and finding your UTR explains each stage in more detail.
Written by:
Tax Rebate Services Editorial Team
Reviewed by:
Tony Shanks
,
qualified Taxation Technician (ATT)
Last updated:
This article provides general information and is correct as at the date shown. It isn't personalised tax advice — for help with your own circumstances, speak to a qualified adviser or HMRC.
