Every self-employed construction worker needs a UTR (Unique Taxpayer Reference) before contractors can pay you properly under CIS. It's free from HMRC — never pay a website for it. Here's the whole route.
Do it free at gov.uk (search “register self-employed”) or in the HMRC app. You'll need your National Insurance number, address and personal details. Takes about 10 minutes.
HMRC posts your 10-digit UTR to your address (it also appears in the HMRC app once issued). No one can legally speed this up — anyone charging for “fast UTR” is selling you nothing.
Once you have the UTR, register for CIS (free, gov.uk or by phone). This is the step people miss — without it contractors must deduct 30% instead of 20% from your pay.
The contractor verifies you with HMRC and deducts 20%. Keep your UTR safe — you'll use it on invoices and your tax return every year.
The UTR is 100% free from HMRC. Websites that charge £20–£100 to “get your UTR fast” just fill the same free form you can fill yourself — some are outright scams that harvest your identity. Only use gov.uk or the official HMRC app.
From your first day self-employed, what you earn and what you spend decides your tax refund. Graftum Pocket logs your days, your CIS deductions and your expense receipts — and builds the statement your accountant needs. Free forever.
Open Graftum Pocket — freeAround 10 working days by post (up to 3 weeks in busy periods). It also shows in the HMRC app once issued. Apply before you start working if you can.
Yes — but the contractor must deduct 30% until you're CIS-registered with your UTR. You claim the difference back later, but it's better to register early.
The UTR is your tax ID; CIS registration links that ID to the construction scheme so deductions drop from 30% to 20%. You need both — UTR first, then CIS.
Official source: gov.uk — always check current rules there. General information, checked September 2026 — not tax advice.