Faster Self Assessment registration, what taxpayers need to know
Overview
HMRC announced an improved online Self Assessment registration service on 9th September 2026. Individuals using the new service through their Personal Tax Account can receive their Unique Taxpayer Reference (UTR) in their online account within 72 hours, according to HMRC, rather than waiting up to 15 days for it to arrive by post. This published turnaround should not be treated as a guarantee for every application.
The service does not change tax deadlines. For the 2025/26 tax year, which ran from 6th April 2025 to 5th April 2026, the normal notification deadline was 5th October 2026. That date has now passed. If you needed to notify HMRC but have not done so, act promptly rather than waiting until January.
HMRC also says around 300,000 Self Assessment customers will have their own or their partner’s Child Benefit payment information pre-populated in their online return. Taxpayers must still check the information and ensure their return is complete.
Detailed Content
What has changed?
The improved registration journey includes forms with some customer information already entered, online support, a save-and-return function and an email or text confirming completion. HMRC says the UTR will appear in the online account within 72 hours for customers using the new service.
Start through the official GOV.UK registration page. You may need to create an account or complete identity checks. If your UTR does not arrive as expected, use HMRC’s registration-response guidance rather than submitting duplicate applications.
The new service is for individual customers with a Personal Tax Account. Agents must continue to use the existing registration processes, including CWF1 or SA1 where appropriate. An accountant cannot assume the same 72-hour route applies to an agent-submitted application.
Who needs to register?
Check whether you need a tax return before registering. Common reasons include:
Being a sole trader with total gross trading income of more than £1,000 in the tax year, before expenses. This can include a genuine side business.
Being a partner in a business partnership.
Having property income, foreign income, savings interest, dividends or other untaxed income that requires reporting through Self Assessment.
Owing Capital Gains Tax that must be reported through Self Assessment.
Owing the High Income Child Benefit Charge and not paying it through an eligible PAYE route.
Not every small receipt requires a return. Tax-free allowances, exemptions, amounts involved and whether HMRC can collect tax another way all matter. Selling your own unwanted possessions is not automatically trading. Use HMRC’s checking tool or obtain advice if uncertain.
Trading income of £1,000 or less may be covered by the trading allowance, subject to its conditions and exclusions. Some people nevertheless choose or need to register, for example to claim a trading loss or pay voluntary National Insurance contributions.
Notification, filing and payment deadlines
For people who need a 2025/26 return and are new to Self Assessment, or need to reactivate an account after not needing a 2024/25 return, the normal notification deadline was 5th October 2026.
The standard deadlines are:
31st October 2026: HMRC must receive a paper return.
31st January 2027: submit an online return and pay the 2025/26 tax balance due.
If you register after 5th October 2026, HMRC’s guidance says it will give you a filing deadline three months from the date on its letter or email. Check the actual notice. This does not extend the normal tax payment deadline of 31st January 2027.
Payments on account for 2026/27 may also be due on 31st January and 31st July 2027. Budget for these where applicable, not just the previous year’s balance.
Child Benefit information in the return
HMRC began introducing Child Benefit pre-population in online Self Assessment returns from 30th June 2026. Its September announcement refers to around 300,000 customers having their own or their partner’s payment information entered automatically.
This does not mean HMRC completes the whole return or verifies all income. Check the figures against your records, including relevant dates and changes in circumstances. HMRC says customers can reject the pre-populated data if it is incorrect.
For 2025/26, the High Income Child Benefit Charge can apply when adjusted net income exceeds £60,000. Where both partners exceed the threshold, the person with the higher adjusted net income is responsible. The person liable is not necessarily the person receiving Child Benefit.
Some people whose only reason for Self Assessment is this charge can pay it through PAYE instead. Eligibility and registration requirements apply. If HMRC already expects a return, obtain confirmation that it is no longer required rather than simply stopping filing.
What if the notification deadline was missed?
Register or reactivate your account promptly and establish what you owe. Missing 5th October does not automatically trigger an immediate fixed fine.
For an ordinary Self Assessment failure to notify, HMRC’s published guidance links the penalty to tax remaining unpaid at the normal 31st January payment deadline. If all relevant tax is paid by that deadline, the tax-geared failure-to-notify penalty will normally be nil. This does not remove the notification obligation or any separate filing requirements.
Where a penalty applies, its amount depends on the relevant unpaid tax, behaviour and disclosure circumstances, not simply how many days late registration was. An unprompted, complete disclosure can reduce penalties. A reasonable excuse may provide grounds to challenge a penalty, but neither relief nor cancellation is automatic.
Separate late filing and payment risks
A late return can attract an initial £100 penalty even if no tax is payable. Further penalties can arise after three, six and twelve months. Apply the filing deadline HMRC has actually given you, including any later deadline following late registration.
Late payment attracts interest. Separate late payment penalties are normally 5% of unpaid tax at 30 days, six months and twelve months, subject to the applicable rules and any agreed arrangements. Interest and different penalties can apply to the same case, but each has its own conditions.
Step by Step Procedure
Check whether your 2025/26 circumstances require a Self Assessment return, using HMRC’s checking tool or professional advice.
Gather your National Insurance number, contact details, relevant start dates and income records. Find your existing UTR if you have one.
Register through GOV.UK, or follow the reactivation process if you previously registered. As 5th October 2026 has passed, do this promptly if you missed the deadline.
Keep the confirmation and check your online account for your UTR. Follow up through HMRC’s official guidance if it does not arrive as expected.
If an accountant assists, agree who will register you and complete the separate agent-authorisation process. Do not share your personal sign-in details.
Check the filing deadline in HMRC’s notice and prepare the return. Review all pre-populated information, including Child Benefit figures.
Calculate and arrange payment by 31st January 2027, including any first payment on account. A later filing deadline does not automatically give more time to pay.
Retain records and obtain advice promptly if you cannot pay, need to correct information or receive a penalty notice.
Frequently Asked Questions and Answers
Do I need to register if I earned only a small amount?
Not necessarily. Sole-trader gross trading income above £1,000 generally requires registration, even if profit is low. Below that amount, check the trading allowance conditions and any other reasons for filing. Property and investment income have separate rules.
What if I registered before but later stopped trading?
You may need to reactivate your Self Assessment account. Find your existing UTR and follow HMRC’s service rather than assuming you need a new number or that the old account is automatically active.
Is the 72-hour UTR turnaround guaranteed?
HMRC publishes a 72-hour online turnaround for individuals using the new service. Do not assume every application, registration route or case will meet it, and do not use it as a reason to delay registration.
Will HMRC complete my return if I claim Child Benefit?
No. Some online returns have Child Benefit payment information pre-populated, but you must check it and report all other relevant information. The person liable for the charge may be the claimant’s partner.
Must everyone owing the Child Benefit charge use Self Assessment?
No. An eligible PAYE route is available for some people who do not need a return for another reason. If you are already in Self Assessment, check with HMRC before stopping your returns.
Can an accountant register me?
An accountant can assist and use the appropriate agent registration process. The new Personal Tax Account journey is for individuals, not agents. You remain responsible for your tax and for approving the information in a return submitted on your behalf.
What should I do if I missed 5th October 2026?
Notify HMRC now, check your filing notice and arrange payment by 31st January 2027. There is no automatic fixed late-registration fine, but unpaid tax and missed filing deadlines can create separate penalty and interest risks.
Does faster registration reduce my tax bill?
No. It helps you access Self Assessment sooner. Your liability still depends on your income, allowable deductions, reliefs and circumstances.