How to Register as a CIS Contractor with HMRC

03 February 2025

If you plan to hire subcontractors in the construction industry, you must register as a CIS contractor with HMRC. This ensures that you deduct the correct tax from your subcontractors' payments. Here’s a step-by-step guide to getting registered:

Check if You Need to Register

You must register as a CIS contractor if:

• You pay subcontractors to carry out construction work.
• Your business spends more than £3 million on construction work within a 12-month period, even if construction is not your main business.

Register Your Business

Before registering for CIS, you must have a Government Gateway account and be registered for PAYE (Pay As You Earn). If you haven’t done this, you can register online via the HMRC website.

Register for CIS

Once you have a PAYE reference, you can register for CIS:

• Online: Log in to your Government Gateway account and follow the steps to register as a CIS contractor.
• By Phone: Call the HMRC CIS helpline on 0300 200 3210.

Verify Your Subcontractors

Before paying any subcontractors, you must verify them with HMRC to check their CIS status and determine how much tax to deduct (20% for registered subcontractors, 30% for unregistered ones).

Deduct and Pay CIS Tax

Each time you pay a subcontractor, deduct the correct amount of tax and report it to HMRC through your monthly CIS return. Once registered, you must keep accurate records of payments and deductions to avoid penalties.