How do I file a Self Assessment tax return for the first time?

How do I file a Self Assessment tax return for the first time? Register with HMRC, wait for your 10-digit UTR, set up your online sign-in, then file your 2025-26 return online by 31 January 2027 and pay any tax owed by the same date. Register now. GOV.UK says HMRC will then send you a letter or email with a filing deadline 3 months from its date. You must still pay the tax by 31 January 2027, or you may get a failure to notify penalty. Your 10-digit Unique Taxpayer Reference (UTR) and sign-in details for HMRC online services. If you have none, you can create a Government Gateway or GOV.UK One Login sign-in, and you may need to prove your identity. No. GOV.UK says you can save your entry and go back to it later. If you do not know a figure yet, you can use a provisional figure, tell HMRC, and update it once you know. Read the full answer, with every source, at rightotax.co.uk.