Registering for an HMRC User ID, Password and UTR. Register for self-assessment with the HMRC here. Complete the form.  Sign a printed copy (sent to your email address) then post it to the HMRC.  The address is on the form. Your UTR and activation code will arrive via post within 8 weeks.   Activate your registration with HMRC here within 28 days after receiving the code. If you miss the activation date you will need to submit another form as step 1. Goto to Click Services you can add in the menu on the left, then enrol for Self-Assessment.                                               Make sure you save your HMRC User ID, Password and UTR (case-sensitive). You can always check your credentials here. Please note if you enter the wrong User ID or password more than twice your account will be locked for two hours.     Other Keywords: numbers; code; document; record; validate; U.T.R.; UTI