The CIS Verification Process

Key facts

Contractors must verify every subcontractor with HMRC before making the first payment under each contract.
Verification can be done online (HMRC business tax account) or by phone (0300 200 3210).
HMRC returns one of three results: matched — gross (0%), matched — net (20%), or unmatched (30%).
You need the subcontractor’s name, UTR, and NI number (or company registration number) for verification.
Verification is valid for the current tax year. Re-verify if a new tax year starts or you have not paid the subcontractor for two consecutive tax years.

Why Verification Is Required

Verification is a core part of the CIS process. It ensures that contractors apply the correct deduction rate to each subcontractor and prevents fraud and identity theft within the scheme.^[1]

Without verification, a contractor would not know whether a subcontractor is registered for CIS, holds gross payment status, or is completely unregistered. Applying the wrong deduction rate can lead to penalties for the contractor.

When Must You Verify?

You must verify a subcontractor with HMRC:^[2]

Before the first payment under each new contract with a subcontractor
At the start of each new tax year (6 April) if you continue working with the same subcontractor
If you have not included the subcontractor in a CIS return for two consecutive tax years
If HMRC notifies you that the subcontractor’s status has changed

You do not need to re-verify for every single payment within the same tax year to the same subcontractor — the initial verification covers all payments in that tax year.

How to Verify a Subcontractor

There are two methods for verifying subcontractors:^[1]

Online Verification

Sign in to your HMRC business tax account (Government Gateway)
Go to the Construction Industry Scheme section
Select “Verify a subcontractor”
Enter the subcontractor’s details (see table below)
HMRC returns the verification result immediately

Phone Verification

Call the CIS helpline on 0300 200 3210 during opening hours (Monday to Friday, 8am to 6pm). Provide the subcontractor’s details and HMRC will give you the verification result over the phone.

Information Needed for Verification

Subcontractor Type	Information Required
Individual (sole trader)	Full name, Unique Taxpayer Reference (UTR), National Insurance number
Partnership	Partnership name, partnership UTR, UTR of the nominated partner
Limited company	Company name, company UTR, company registration number

Tip: The details must match HMRC’s records exactly. A misspelled name, an old address linked to the UTR, or a transposed digit in the NI number can cause an “unmatched” result. Always ask the subcontractor to confirm their details carefully.

Verification Results

HMRC will return one of three verification outcomes:^[3]

Result	Meaning	Deduction Rate	What to Do
Matched — gross	Subcontractor is registered and holds gross payment status	0%	Pay the full amount with no deduction
Matched — net	Subcontractor is registered for CIS	20%	Deduct 20% from the labour element of the payment
Unmatched	HMRC cannot match the subcontractor to their records	30%	Deduct 30% from the labour element of the payment

Dealing with “Unmatched” Results

An “unmatched” result means you must deduct at the higher 30% rate. Common reasons for an unmatched result include:^[3]

The subcontractor is not registered for CIS
The name provided does not match HMRC’s records (e.g. trading name instead of legal name)
The UTR or NI number is incorrect or has been transposed
The subcontractor has recently changed business structure (e.g. incorporated) and the new entity is not yet registered

If you get an unmatched result, you should:

Inform the subcontractor of the result
Ask them to check and correct their details with HMRC
Re-verify once they confirm their details have been updated
In the meantime, apply the 30% deduction rate — you must not use a lower rate without HMRC confirmation

Cannot skip verification: You must not pay a subcontractor without verifying them. If you cannot verify them (e.g. they cannot provide a UTR), you must deduct at 30%. Paying gross or at 20% without verification is a compliance failure.

The Verification Reference Number

When you verify a subcontractor online, HMRC provides a verification reference number. You should record this number and keep it with your CIS records, as it proves you carried out verification as required. If HMRC later queries your deductions, this reference demonstrates compliance.

Verifying Multiple Subcontractors

If you work with many subcontractors, you can verify them in bulk through HMRC’s online service. Some commercial payroll and CIS software also offers built-in verification functionality, connecting directly to HMRC’s systems via APIs.

Frequently Asked Questions

When do I need to verify a subcontractor?

You must verify a subcontractor before making the first payment to them under a contract. If you have not included them in a CIS return for two full consecutive tax years, you must re-verify them. You should also re-verify at the start of each new tax year.

What information do I need to verify a subcontractor?

For individuals, you need their full name, Unique Taxpayer Reference (UTR), and National Insurance number. For companies, you need the company name, company UTR, and company registration number. For partnerships, you need the partnership name, partnership UTR, and the UTR of the partner you are dealing with.

What does “unmatched” mean?

An unmatched result means HMRC cannot match the subcontractor’s details to their records. This usually means the subcontractor is not registered for CIS, or the details provided (name, UTR, NI number) do not match HMRC’s data. You must deduct at 30% for unmatched subcontractors.

What if the subcontractor disputes the deduction rate?

If a subcontractor believes the wrong rate has been applied, they should check their details with HMRC directly. The contractor must apply the rate HMRC provides during verification. If HMRC later confirms a different rate, adjustments can be made on a subsequent CIS return.

Sources

Verify a subcontractor for CIS — GOV.UK
What you must do as a CIS contractor — GOV.UK
CIS: verification (CISR43000) — HMRC