How to register as a CIS contractor

Do I need to register as a CIS contractor?

Yes, if you pay anyone who is not your employee for construction work. GOV.UK says you must register as a contractor if you pay subcontractors to do construction work. You may be a sole trader, in a partnership or own a limited company.

There is no minimum. One subcontractor on one job is enough. If someone pays you for construction work as well, you are a subcontractor for that work too, and You must register as both if you fall under both categories. How to register as a subcontractor

Once you are registered, how CIS works sets out the six things you do each month.

When do I have to register for CIS?

Before you pay your first subcontractor. GOV.UK: You must register for CIS before you take on your first subcontractor. HMRC’s CIS340 guide puts it the same way: When you’re about to take on and pay your first subcontractor, regardless of whether that subcontractor is likely to be paid gross or under deduction.

Do not go too early either. On the employer registration, GOV.UK says: You must register before the first payday to get your employer PAYE reference number. You cannot register more than 2 months before you start paying people.

How do I register as a CIS contractor?

Through HMRC’s employer registration. There is no separate CIS form for a contractor. GOV.UK: To register as a contractor, you need to follow the process for setting up as a new employer. Step by step:

1. Check the person is a subcontractor, not an employee. GOV.UK says you must check whether you should employ them instead: You may get a penalty if they should be an employee instead.
2. Register as an employer with HMRC. Do this even if nobody works for you on PAYE. You normally need to register as an employer with HM Revenue and Customs (HMRC) when you start employing staff, or using subcontractors for construction work. Start on GOV.UK’s register as an employer page.
3. Say you will use subcontractors. The registration asks whether the business will use subcontractors under the Construction Industry Scheme (CIS), or reclaim CIS deductions taken from payments. Answer yes. That is the step that makes you a CIS contractor.
4. Register online, by phone or by post. GOV.UK asks a few questions about your business and then tells you which. Most limited companies can register online. Sole traders and partnerships are pointed to their own route.
5. Wait for HMRC’s letter. you’ll get a letter from HM Revenue and Customs (HMRC) with the information you need to start working as a Construction Industry Scheme (CIS) contractor, including your employer PAYE reference number. Keep it: you need these references to verify subcontractors, file returns and pay HMRC.
6. Set up your online access. If you registered online you also get an activation code for PAYE Online (within 10 working days). Then sign in to HMRC’s CIS online service, where you verify subcontractors and send your monthly returns.

Source: GOV.UK, how to register as a CIS contractor. Stuck? Call the new employer helpline or the CIS helpline.

What do I need to register as a CIS contractor?

Your business details and a few facts about who you will pay. If you register by phone, HMRC asks for:

• The business name, address and phone number (the address cannot be a PO box)
• Your trading name, if it is different
• The type of business, for example plumbing or electrical work
• The business’s Unique Taxpayer Reference (UTR)
• The name and National Insurance number of the person running the scheme, each partner, or each company director
• Your company registration number, if you are a limited company
• The date of your first payday
• Whether you will be using subcontractors in the construction industry

Source: GOV.UK, register as an employer. The list ends by asking whether you’ll be using any subcontractors in the construction industry.

How long does CIS contractor registration take?

HMRC does not publish a fixed time. The wait is for the letter with your references: you’ll get a letter containing your PAYE and Accounts Office references. For the current wait, use HMRC’s reply times tool, which is updated every week.

So register as soon as you know your first payment date, inside the 2 months window, rather than the week before.

What if I already have employees on PAYE?

Then CIS is added to the PAYE scheme you already run. GOV.UK: If you already have employees, HMRC will change your existing PAYE Scheme to a PAYE/CIS scheme. If you are new to both, CIS340 says HMRC will set up a Contractor Scheme (and a PAYE Scheme if you have asked us to).

What do I have to do once I am registered?

Six things, and they run on tax months, not calendar months. Each tax month, a contractor has to:

1. Verify each new subcontractor before you pay them. Before you can pay a new subcontractor, you’ll need to ‘verify’ them. HM Revenue and Customs (HMRC) will tell you how much to deduct from a subcontractor’s payments when you verify them. Usually that is 20% of the labour, or 30% if HMRC cannot match them.
2. Take the deduction off the labour only. VAT and materials the subcontractor bought come off first. How a CIS deduction is worked out
3. Give each subcontractor a statement. GOV.UK: you must give the subcontractor a payment and deduction statement within 14 days of the end of each tax month.
4. File your CIS return. Send your monthly returns to HMRC by the 19th of every month following the last tax month. You should file CIS returns every month. In a month you paid nobody, you send a nil return or tell HMRC you are inactive.
5. Pay HMRC the deductions. Pay HMRC every month by the 22nd (or the 19th if you’re paying by post). If that day is a weekend or bank holiday, an electronic payment has to arrive by the banking day before.
6. Keep records. Every payment, every deduction and the materials figures behind them. How long to keep CIS records

Source: GOV.UK, what you must do as a CIS contractor. A return 1 day late costs £100, even when you owe nothing.

More on each: verifying a subcontractor and CIS returns, deadlines and penalties.

When is my first CIS return due?

By the 19th of the month after the tax month you first pay someone in. A tax month runs from the 6th of one month to the 5th of the next.

Say you first pay a verified subcontractor on 20 January 2027, for £1,000 of labour:

• You take £200 off (20%) and pay them £800.
• That payment falls in the tax month 6 January to 5 February.
• Their payment and deduction statement is due by Friday 19 February 2027.
• Your CIS return is due by Friday 19 February 2027.
• The £200 must reach HMRC by Monday 22 February 2027, if you pay electronically.

Then it repeats every month for as long as you are registered. Get a reminder before each deadline

Do I need to register if my business is not in construction?

Only if you spend enough on construction work. You must register once your business spends more than £3 million on construction in any 12 months. HMRC calls this a deemed contractor.

HMRC’s manual leaves things out of that figure: the term ‘expenditure’ means expenditure excluding VAT, and it does not include the cost of materials or non-construction expenditure included in a construction contract. How the deemed contractor test works

Other questions about registering as a contractor