HM Revenue and Customs (HMRC) has launched an improved registration service making it easier than ever to register for Self Assessment.

Anyone who is unsure if they need to submit a tax return can use HMRC’s free online checking tool on GOV.UK to understand what, if anything, they should do next. More than 640,000 customers registered for Self Assessment in the 12 months to 31 March 2026.

Those who need to file a Self Assessment tax return for the first time for 2025 to 2026 must register by 5 October 2026, or they could incur a penalty. They can register via GOV.UK.

The deadline for submitting a tax return and paying any tax owed for the 2025 to 2026 tax year is 31 January 2027. However, customers who have income to declare and aren’t already registered for Self Assessment need to do so before they can start their tax return.

Myrtle Lloyd, HMRC’s Chief Customer Officer, said: “Anyone new to Self Assessment may not realise they need to register before they can submit their tax return. Registering is quicker and easier than ever. And if you register now, you’ll get your Unique Taxpayer Reference so you can start completing your return with plenty of time before the 31 January deadline.”

Improvements to HMRC’s online registration system means that those new to Self Assessment will be able to sign up quickly and easily through their Personal Tax Account using a more streamlined process including:

  • forms with pre-populated customer information
  • signposting to online support during the registration process
  • save and return functions with no loss of data
  • confirmation email or text once registration is complete

Once they’ve registered, customers will be issued with a Unique Taxpayer Reference (UTR) so they can start their return. Those using the new service will receive their UTR in their online account within 72 hours instead of waiting up to 15 days for it to arrive in the post.

Customers can create a Personal Tax Account using their Government Gateway or GOV.UK One login details. Go to GOV.UK to find out more.

A full list of reasons why someone may need to fill in a tax return can be found on GOV.UK, and includes those who:

  • are newly self-employed and have earned gross income over £1,000
  • earned below £1,000 and wish to pay Class 2 National Insurance Contributions voluntarily to protect their entitlement to State Pension and certain benefits
  • are a new partner in a business partnership
  • have received any untaxed income over £2,500

If someone no longer needs to complete a tax return, it’s important they notify HMRC as soon as possible otherwise a return will be expected and a penalty for non-submission will be issued. Until HMRC confirms you no longer need to submit a tax return you should continue to meet your Self Assessment obligations. Find out how to tell HMRC on GOV.UK.