For tax year 2025/26, if there is a need to register for Self-Assessment, this needs to be done by 05 October 2026. On 09 September 2026, HMRC announced an ‘improved’ registration service.
This can be done via the Personal Tax Account using Government Gateway or GOV.UK One login details. The benefits of this are that the necessary Unique Taxpayer Reference (UTR) is received within 72 hours (online) rather than having to wait for it to arrive in the post.
Note that when registering for 2025/26, the individual will have to answer whether:
- They completed a Self-Assessment return for the last tax year (in which case there will already be a UTR);
- They did not complete one last tax year but have done before (in which case, again, the UTR will exist); or
- This is the first registration for Self-Assessment (and the UTR is required)
For Bookkeepers
Anything that makes registration quicker and easier is welcomed by ICB.
Remember that you and your clients can use the free HMRC ‘Check if you need to send a Self-Assessment tax return’ online tool to find out whether there is an obligation to send a tax return and, therefore, complete registration if this is the first time. As the tool says, if HMRC have already sent a letter, registration must be done before the deadline quoted in the correspondence.
Equally important, though, are the responsibilities to:
- Deregister from Self-Assessment if there is no longer a reason for completing a return. Be aware that HMRC may have sent your client an ‘exit letter’; so you may need to
- Re-activate an existing Self-Assessment record which can be done via HMRC’s Agent Dedicated Line (ADL)