Quick answer
Sign up on GOV.UK with the Government Gateway user ID and password you use for Self Assessment, or ask your accountant to sign you up. You need to be registered for Self Assessment and to have filed a return in the last two years. Since September 2026, HMRC has also been signing people up automatically if they haven’t done it themselves.
Before you start
You’re registered for Self Assessment and have submitted a tax return in the last 2 years.
You have your Government Gateway user ID and password.
You can verify your identity, either with a photo match in the HMRC app or by answering security questions.
You know the start date of any business or property income that began in the last 2 tax years.
If you’re a sole trader: your business name, address and a short description of the trade.
You’ve chosen software that works with MTD for Income Tax, or will before your first quarterly update.
How to sign up yourself
Check you need to join, using our MTD checker.
Go to HMRC’s sign-up service on GOV.UK and sign in with your Self Assessment Government Gateway details.
Confirm your identity.
Check each income source HMRC shows you, and add any that are missing.
Choose the tax year you’re starting from.
Connect your software to HMRC so it can send your updates.
HMRC’s step-by-step instructions are in its guidance on signing up.
Signing up through an accountant
Your accountant or another agent can sign you up instead. They’ll send you an authorisation request, which you need to accept before they can act for you.
If HMRC has signed you up
From September 2026, HMRC began signing up people who need MTD from April 2026 and hadn’t done it themselves. It uses the information it already holds, and sends a confirmation letter through your HMRC online services or by post.
If that’s you, you need to check the income sources HMRC has listed, get compatible software, and send any quarterly updates you’ve missed so far. There are no penalty points for late quarterly updates in 2026/27, but the updates still need to be sent before your final declaration.
If you think you shouldn’t have been signed up, contact HMRC’s Self Assessment helpline or check whether you’re exempt. HMRC explains the next steps in its guidance for people it has signed up.
When to sign up
If you need MTD for the 2026/27 tax year, sign up now. If you’re joining in April 2027 or April 2028, sign up before your start date so your software and records are ready for the first quarter.
Signing up voluntarily
If you’re under the threshold, you can still choose to sign up for the current tax year or the next one.