Quick answer
Use the same Government Gateway user ID and password you use for Self Assessment. When you sign up for MTD for Income Tax, you may need to confirm your identity with a photo match in the HMRC app or by answering security questions. If you’ve lost your details, recover them on GOV.UK before you start.
Key facts
Use your existing Self Assessment Government Gateway login
You may need to verify your identity
Your software connects to HMRC through the same login
Agents use their own agent services account
Identity checks
A photo match using the HMRC app, or
Answering security questions using information HMRC holds about you
Lost your details?
Use the ‘Sign in to your HMRC account’ page on GOV.UK to recover your user ID or reset your password. Do this well before a deadline, because recovery can involve a letter in the post.
Connecting your software
Your MTD software asks you to sign in to HMRC once to give it permission to send updates for you. You may need to repeat this from time to time.