What you need, the steps with the gov.uk links, and what the 30% rate is doing to your invoices in the meantime. Or WhatsApp me and we'll do it together, it's twenty minutes.
Subcontractor — you're on the tools for a contractor and you get paid as a sole trader, through your own limited company, or as a partner. If you're on the payroll with a payslip, you're an employee and none of this applies to you.
Contractor — you pay other people to do construction work for you. Plenty of lads end up as both once the work picks up, and if that's you, you register as both. The contractor rules are on gov.uk; the rest of this page is for the subbie.
Have these to hand before you start and the whole thing's twenty minutes on your phone.
No UTR yet? That's normal if you've only just gone self-employed. You register as self-employed for Self Assessment instead and tick "working as a subcontractor" when it asks, and HMRC does both registrations in one go. The UTR comes in the post, so do it this week, not the week the first invoice goes in.
Until you're registered and the contractor's verified you, they have to take 30% off instead of 20%. On every invoice. It's not gone forever, it's sat with HMRC against your tax bill and it comes back when your return goes in, but that could be a year away and in the meantime it's your money you're not seeing.
| £2,000 labour invoice | Registered (20%) | Not registered (30%) |
|---|---|---|
| Contractor sends to HMRC | £400 | £600 |
| Lands in your account | £1,600 | £1,400 |
Materials, VAT and plant hire on the invoice aren't deducted either way — only the labour. Put your own invoice in the calculator →
Here's the order to do it in. The links go straight to the gov.uk pages, not to me.
Full HMRC guide: What you must do as a CIS subcontractor. Turning over £30,000+ a year on labour with a clean tax record? Gross payment status means no deductions at all — that's a conversation, not a form.
Once HMRC's got you on the system, you give every contractor your UTR and the exact name you registered under, spelt the same. They run it past HMRC before they pay you, HMRC tells them 20%, and that's it from then on. Give them a different name, your trading name when you registered as yourself or whatever, and it comes back as 30% again, so keep it the same everywhere.
Twenty minutes. You go through the form on your phone, I'm on the other end telling you what goes in each box, and it's done. Then every statement a contractor gives you, you photograph it and send it to me, and by April your refund's already worked out. First month's free on Solo and Growth, no card, nothing to cancel, and if it's not for you after that, that's cool.
WhatsApp me — I'll reply today Check an invoice on the CIS Tax CalculatorOnly if you're doing construction work for a contractor. Being self-employed on its own doesn't put you in CIS, it's the work that does. If you're on someone's payroll you're an employee and it doesn't apply, and if you're doing domestic jobs straight for homeowners, that's not CIS either, a homeowner isn't a contractor.
Yes. A UTR just means you're registered for Self Assessment. CIS is a separate registration on top of that, and until it's done any contractor who verifies you gets told 30%. If you got your UTR by registering as a subcontractor in the first place you're already in, but if you got it years ago for something else, you need to do the CIS one as well.
There isn't one, not for a sole trader anyway. People ask because a contractor says "give me your CIS number", and what they actually need is your UTR, your National Insurance number and the exact name you registered with. HMRC gives the contractor a verification reference when they check you, but that's their number, not yours.
The online form itself is about twenty minutes. If you needed a UTR first, that comes by post, and HMRC publish how long they're currently taking to send them, it changes through the year. Once you're on the system a contractor can verify you straight away. I'd do it before you start on site, not after the first invoice.
Yes, and it's the company that registers, not you. You need the company's UTR and its Companies House number. The difference is what happens to the deductions: they come off what the company owes HMRC through its PAYE each month rather than off your personal tax, and anything left over gets claimed back after the tax year ends. It's a different process to a sole trader's refund.
No, once you're registered you're registered. Two things do move though. A contractor has to verify you again if they haven't had you on one of their monthly returns in the current or last two tax years, so a long gap with the same firm can mean a re-check. And if you're on gross payment status, HMRC review that every year.
Next: CIS or PAYE — what changes · your first CIS statement · what your refund might be · how CIS refunds work · what it costs from £69 a month