A UTR number is the 10-digit Unique Taxpayer Reference HMRC gives you when you register for Self Assessment or set up a limited company. Under CIS, it's the number that identifies you for tax. No UTR, no CIS registration. No CIS registration, and contractors take 30% off every payment instead of 20%. That's why every portal, agency and main contractor asks for it before they ask for your price.
I ran a property maintenance company in London on a network of subbies, working for housing associations and letting agents. My rule was simple: no UTR, no start date. Nobody was being difficult. That's just how money moves legally on a construction job.
What a UTR number actually is
It's a 10-digit reference from HMRC. On letters it might just say "tax reference". You get one when you register for Self Assessment or when you set up a limited company.
There are two kinds, and people mix them up all the time.
- A personal UTR, for you as an individual. Sole traders and partners use this one.
- A company UTR, for your limited company's Corporation Tax. It's a different number from the director's personal one.
It isn't your National Insurance number, your Companies House number or your VAT number. Portals often ask for two or three of these together, so keep them in one place.
It costs nothing. HMRC doesn't charge for a UTR. GOV.UK says it usually arrives by post around 15 days after you register, longer if you live overseas (checked 9 October 2026). If you already have one, it's in your Personal Tax Account, the HMRC app, or on old returns and letters from HMRC.
Why CIS runs on your UTR
The Construction Industry Scheme is HMRC's way of collecting tax from subbies as they get paid. The contractor deducts money from your invoice and passes it to HMRC. It counts as an advance payment towards your tax and National Insurance.
If you're registered for CIS, the deduction is 20%. If you're not, it's 30%. Get gross payment status and nothing is deducted at all. That's a separate application with its own tests, covered in our guide to CIS subcontractor work and getting paid gross.
To register for CIS you need the UTR for your business. That's written straight into HMRC's own registration guidance. Before a contractor pays you, they verify you with HMRC, and HMRC tells them which rate to use. That check runs on your name, your UTR and your NI number or company number.
So when someone asks for your UTR, they're not being nosy. They can't pay you correctly without it. If CIS itself is new to you, start with what CIS is and how it works.
How many UK work sources ask for a UTR
We track UK places where contractors and subbies find work: council portals, housing association supplier systems, NHS trusts, universities, frameworks, agencies and labour apps. As of July 2026, at least 32 of the 557 UK work sources we tracked ask for a UTR by name. We recounted from the same data in October 2026 and the number held.
Here's roughly where those 32 sit:
- Councils and shared-service procurement teams make up the biggest group, at 11.
- Universities account for 7.
- Housing associations and procurement groups account for 5.
- Agencies, labour apps and job boards paying on a CIS basis account for 5.
- NHS bodies account for 3, and the last one is a framework.
That 32 is a floor. A lot of public-sector supplier portals use a standard registration form with one reference box that takes either a Companies House number or a UTR. We only counted the sources that name the UTR. A sole trader has no Companies House number, so on those forms your UTR is your company identity. In practice, far more than 32 doors want that number.
Here's the part people hate hearing. The UTR won't win you anything. It's the bare minimum to get through the form. Insurance, accreditations and references do the selling. But without it you can't even get as far as being judged on those.
Do you need a UTR?
Not everyone does. Here's how it breaks down.
| Your situation | Need a UTR? | What matters |
|---|---|---|
| Sole trader doing work for contractors | Yes | Personal UTR, then register for CIS |
| Limited company subbie | Yes, the company's | The company registers for CIS with its Corporation Tax UTR |
| Partnership | Yes | Partnership UTR, plus each partner's details |
| Operator paying subbies on construction work | Yes | You register as a CIS contractor as well |
| Sole trader working only for homeowners | Usually, for Self Assessment | CIS doesn't cover work done directly for homeowners |
| Employed on PAYE by a contractor | No, not for CIS | Your employer runs your tax through payroll |
| Paid through an umbrella or PAYE agency | Not for CIS | Check your contract to see how you're actually paid |
| Based abroad, working in the UK | Yes | GOV.UK says overseas subbies should still register for CIS |
If you're not sure whether you're employed or self-employed, HMRC has an employment status check. Use it before you register for anything. Getting your status wrong causes more grief than a missing number.
How to get your UTR, step by step
- Check you don't already have one. Look in the HMRC app, your Personal Tax Account and any old tax letters. People register twice and confuse themselves.
- If you're a sole trader, register as a new business for Self Assessment and choose "working as a subcontractor" when it asks. HMRC registers you for Self Assessment and CIS at the same time. One job, done.
- If you're a limited company, the company UTR comes after incorporation. You can request the Corporation Tax UTR online and HMRC posts it to the address registered at Companies House. Then register the company for CIS.
- Give it the post time. Around 15 days is normal. Don't leave it until the week a contractor wants to pay you, because until you're registered they deduct at 30%.
- Once it lands, put it on your invoice template and your profiles, and keep it somewhere you can copy it from your phone. You'll type it into forms more often than you think.
The official starting point is HMRC's page on finding your UTR number, and their guide to what you must do as a CIS subcontractor covers registration properly.
Don't pay a website that offers to "get your UTR" for you. HMRC does it for free. If you want an accountant to handle registration as part of looking after your books, fine. That's a service you're paying for, not a fee for the number.
If you're the operator: the other side of the UTR
Most people only think about their own UTR. When you're the operator, meaning the contractor business that manages the client, the job and the subbies, you're also a CIS contractor. That means you need every subbie's UTR before you pay them.
My advice is to ask for it at onboarding, not on payment day. On payment day you've got a subbie chasing money and you're chasing a number. That's how mistakes happen.
This is where Plan@Job fits. It's AI-powered project and operations management for construction and property businesses. You run clients, jobs, subcontractors and in-house operatives in one place. You can split a job into internal stages with scope, dates, status and costs, and give some stages to subbies and keep some in-house. The client sees the agreed scope and price and the evidence you share. Your stage costs and which subbie did what stay internal. More on that in project management.
Be clear on who decides what. In supported workflows a subbie can price before they're fully vetted, but whether they get the job is still your call. The HMRC side stays with you or your accountant. That means verifying the subbie, applying the right deduction and filing your monthly CIS returns. The software runs the job. It doesn't make your tax decisions for you.
The next move
If you don't have a UTR yet, register today. It's free and it takes about two weeks to arrive. Every week you leave it is another week of 30% coming off your money.
You'll probably want Plan@Job if you're past doing every job yourself, you've got subbies across several sites, and right now your onboarding lives in a WhatsApp thread. If that's you, set up your contractor account and run the next job through it.
FAQ
Can I start work before my UTR arrives?
Yes, you can do the work. But if you're not registered for CIS when the contractor verifies you, they deduct 30% instead of 20%. Register as early as you can so your first proper invoice goes through at the right rate.
Is my UTR the same as my National Insurance number?
No. Your NI number follows you for life and covers your National Insurance. Your UTR is your Self Assessment or company tax reference from HMRC. CIS verification often asks for both, so have both ready.
Does a limited company need its own UTR for CIS?
Yes. The company gets its own Corporation Tax UTR, separate from the director's personal one. The company registers for CIS with that number, and contractors verify the company, not you personally.