Is my CIS number the same as my UTR?

Is my CIS number the same as my UTR? In practice, yes. As of October 2026, GOV.UK describes no separate CIS number for subcontractors: contractors verify you using your 10-digit Unique Taxpayer Reference (UTR), your National Insurance number and your registered name. GOV.UK does not describe one. HMRC writes to confirm your registration and tells you what to give contractors, and they verify you using your UTR, National Insurance number and the name you registered with. In HMRC's examples it is a V followed by 10 digits, such as V0004528765. If HMRC could not verify you, one or two letters are added to the end, such as V0004528765/A, and 30% is deducted. In your personal tax account, the HMRC app, previous tax returns and HMRC letters such as notices to file a return or payment reminders. It is a 10-digit number and is sometimes just called your tax reference. Read the full answer, with every source, at rightotax.co.uk.