HMRC has launched an improved online service to make it easier for individuals to register for self-assessment. Anyone who needs to submit a tax return for the first time for the 2025–26 tax year should notify HMRC by 5 October 2026 to avoid a potential penalty.

The new service is available through a Personal Tax Account and includes pre-populated information, online support during registration and the ability to save and return without losing information. Taxpayers will also receive confirmation by email or text when their registration is complete.

Once registered, taxpayers receive a Unique Taxpayer Reference (UTR), which is needed to complete their tax return. Under the new service, the UTR should appear in the taxpayer's online account within 72 hours, instead of taking up to 15 days to arrive by post.

Taxpayers who are unsure whether they need to submit a tax return can use HMRC's online checking tool. Those who need to register may include newly self-employed individuals with gross trading income above £1,000, a new partner in a business partnership and taxpayers with more than £2,500 of untaxed income.

The deadline for submitting the 2025–26 self-assessment tax return and paying any tax due is 31 January 2027.

Anyone who no longer needs to complete a tax return should tell HMRC as soon as possible. Until HMRC confirms that a self-assessment return is no longer required, taxpayers should continue to meet their self-assessment filing obligations.

The new registration service is currently available to individual taxpayers with a Personal Tax Account. Agents must continue to use the existing registration processes, including using forms CWF1 or an SA1, to register.