How to Register for CIS as a Subcontractor — Step by Step

If you're working in construction as a subcontractor and you're not registered with HMRC under CIS, you're being deducted 30% from your labour payments instead of 20%. That extra 10% isn't lost forever — it comes back when you file your Self Assessment — but you're essentially giving HMRC an interest-free loan out of every invoice.

Registering takes about 10 minutes. Here's how.

First — what is CIS registration? The Construction Industry Scheme requires contractors to deduct tax from subcontractor payments and send it to HMRC. The rate depends on your status:

30% if you're not registered with HMRC at all 20% if you're registered as a CIS subcontractor 0% if you have Gross Payment Status

Getting from 30% to 20% is as simple as registering. Getting to 0% (Gross Payment Status) requires a track record of tax compliance and meeting turnover thresholds.

What you'll need before you start Before calling HMRC or registering online, make sure you have:

Your Unique Taxpayer Reference (UTR) — if you don't have one yet, you need to register for Self Assessment first, which takes a few weeks. Do this now if you haven't. Your National Insurance number Your business name (if trading as a business rather than your own name) Your business address and phone number

How to register online Go to gov.uk and sign in to your Business Tax Account (or create one if you haven't got one). Once logged in, find the CIS section and register as a subcontractor. It's a short form — name, UTR, NI number, trade type.

Alternatively, call the HMRC CIS helpline on 0300 200 3210. If you have all your details ready, they can register you over the phone same day.

How long does it take? Online or by phone, registration is usually processed within a few days. Your contractor can check your registration status with HMRC before making your next payment — which is how the 20% rate gets applied.

What happens if you start a job before it's confirmed?

If your contractor verifies you and the registration isn't showing yet, they'll deduct at 30% until it's confirmed. Once you're registered, future payments go to 20%. You claim the difference back at Self Assessment — it's not lost.

How to get Gross Payment Status Gross Payment Status (GPS) means no deductions at all — you receive your full invoice amount. To qualify:

You must have been compliant with all HMRC obligations for the past 12 months — tax returns filed, payments made on time You must pass a turnover test (currently £30,000 for sole traders) HMRC review GPS annually — if your compliance slips, they withdraw it

Apply for GPS through your Business Tax Account or by calling HMRC. It's worth doing once you've got a year of compliance behind you — cash flow is much better when the full amount lands.

Telling your contractor

Once you're registered, tell your contractor so they can re-verify you with HMRC before your next payment. They do this through their own CIS online account — it takes them two minutes and means your rate drops straight away.

Keeping your CIS records straight

For each job, you should know:

The gross invoice amount The labour element The materials element The CIS deduction applied The net amount received

Those deduction amounts need to go on your Self Assessment — they offset your tax bill. If you've had more deducted than you owe in tax, you get a refund.

Dayrates tracks CIS deductions automatically on every invoice and keeps a running record you can give your accountant at year end. No spreadsheets, no adding up deduction slips.

The short version If you're on 30%, you're paying more than you need to. Register today, tell your contractor, and drop to 20% by your next invoice. It takes one phone call.