How to Manage Subcontractors as a UK Tradesperson

Most trade businesses reach a point where one pair of hands isn't enough. You've got more work than you can handle alone, so you bring in another tradesperson to help. It seems straightforward — until HMRC gets involved.

Using subcontractors in the UK construction industry comes with a specific set of legal obligations under the Construction Industry Scheme (CIS). Get it right and it's a perfectly workable arrangement. Get it wrong and you're looking at penalties, backdated deductions, and a very unpleasant conversation with HMRC.

This guide explains exactly what CIS is, what you're required to do as a contractor, and how to manage subcontractors in a way that keeps your business legal, your subbies happy, and your admin under control.

First: Employee or Subcontractor?

Before anything else, you need to be sure the person you're bringing in actually qualifies as a subcontractor rather than an employee. HMRC takes this distinction seriously and the penalties for misclassifying someone — paying them as a subcontractor when they should legally be an employee — can be significant.

A genuine subcontractor typically:

• Works for multiple different clients, not just you
• Invoices for their work rather than receiving a regular wage
• Controls how and when they do the work
• Uses their own tools and equipment
• Can send someone else to do the work in their place
• Doesn't get paid holiday or sick leave from you

If the arrangement looks more like employment — same hours every week, working exclusively for you, using your equipment, under your direct supervision — HMRC may treat them as an employee regardless of what the paperwork says. If you're unsure, use HMRC's Check Employment Status for Tax (CEST) tool before you start paying anyone.

What Is CIS and Does It Apply to You?

The Construction Industry Scheme (CIS) is HMRC's tax system for the construction industry. It requires contractors to deduct tax from payments made to subcontractors and pass that money directly to HMRC as an advance payment towards the subcontractor's tax bill.

CIS applies to most construction work carried out in the UK — building, repairs, demolition, civil engineering, electrical installation, plumbing, decorating, and site preparation all fall under the scheme. If you're a plumber paying another plumber to help on a job, CIS applies. If you're an electrician bringing in a second spark for a large commercial project, CIS applies.

You are a contractor under CIS if you pay subcontractors for construction work. That's the trigger — not the size of your business, not whether you're a sole trader or limited company, not how many subcontractors you use. One subcontractor on one job and CIS rules apply.

Step 1: Register as a CIS Contractor Before You Pay Anyone

This is the rule most tradespeople miss: you must register as a CIS contractor with HMRC before you make your first payment to a subcontractor — not after. You can register online via GOV.UK using your Government Gateway ID.

If you're also doing construction work yourself for other contractors, you'll need to register as both a contractor and a subcontractor. Both registrations are done through the same HMRC system.

Operating as a CIS contractor without being registered is the kind of thing that tends to surface during an HMRC investigation — and by that point the penalties and backdated deductions can be substantial.

Step 2: Verify Your Subcontractor with HMRC

Before making any payment, you must verify each subcontractor's CIS registration status with HMRC. This tells you the correct deduction rate to apply. You can do this online via your HMRC Government Gateway account or through CIS-compatible software.

HMRC will tell you one of three things:

• Gross payment status — deduct nothing, pay the full amount. The subcontractor handles their own tax.
• Registered at standard rate — deduct 20% from the labour element of the payment
• Not registered — deduct 30% from the labour element of the payment

The deduction only applies to the labour portion of the payment — not materials. If your subcontractor charges £2,000 for labour and £500 for materials, the deduction is calculated on the £2,000 only.

Once you've verified a subcontractor, you don't need to re-verify them every time unless HMRC notifies you of a change to their status.

Step 3: Make the Deduction and Issue a Payment Statement

When you pay your subcontractor, you deduct the correct amount from the labour element and pay it to HMRC. The subcontractor receives the remainder — and they can offset those deductions against their annual tax bill, so it's not money lost, just paid earlier.

You must also provide the subcontractor with a payment and deduction statement within 14 days of the end of each tax month. This shows them exactly what they were paid, what was deducted, and what went to HMRC. It's their proof for reclaiming any overpayment at the end of the tax year.

Failing to issue these statements on time is a compliance breach — HMRC can and does issue penalties for it.

Step 4: Submit Monthly CIS Returns to HMRC

Every month, you must submit a CIS return to HMRC showing all payments made to subcontractors during that month. This includes the gross amount paid, the cost of materials, and the amount deducted. If you made no payments that month, you still need to tell HMRC — a nil return is required.

The deadline is the 19th of the month following the payment month. Miss it and the penalties start at £100 for one day late, rising to £200 after two months, £300 after three months, and potentially much higher for persistent non-compliance.

Important change from April 2026: CIS is being incorporated into Making Tax Digital for Income Tax. Contractors will need to submit quarterly digital reports rather than monthly returns, using HMRC-approved software. If you're not already using CIS-compatible software, now is the time to sort it.

Using a Written Subcontractor Agreement

CIS covers the tax side — but it doesn't protect you if a subcontractor does poor work, causes damage on site, or walks off a job halfway through. A simple written subcontractor agreement sets out the scope of work, agreed price, payment terms, and what happens if things go wrong.

It doesn't need to be a complex legal document. The key things to cover are:

• Description of the work and the site address
• Agreed price and what's included (labour only, or labour and materials)
• Start date and expected completion
• Payment terms and how CIS deductions will be handled
• Who is responsible for their own public liability insurance
• What happens if the work isn't completed to standard

Tradify includes subcontractor management features that let you track who's working on which job, log costs against specific projects, and keep a clear record of what was agreed — which is exactly the kind of documentation you need if a dispute ever arises.

Managing the Practical Side

Beyond the tax obligations, the real challenge with subcontractors is keeping jobs on track when you're not physically on site with them. A subcontractor who goes quiet, misses a deadline, or does work that doesn't meet your standard reflects on your business — not theirs.

The tradespeople who manage subcontractors well tend to do a few things consistently:

• Brief the subcontractor properly before the job starts — not just what to do but what standard is expected
• Check in at key stages rather than only at completion
• Keep all job details, notes, and communications in one place so nothing gets lost in WhatsApp threads
• Invoice the end customer only once the work has been checked and signed off

Job management software makes this significantly easier when you're coordinating multiple people across multiple sites. Tradify lets you assign jobs, track progress, attach notes and photos, and manage quotes and invoices — all from your phone.

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CIS Compliance Checklist

• ✅ Registered as a CIS contractor with HMRC before first payment
• ✅ Subcontractor verified with HMRC — correct deduction rate confirmed
• ✅ Deduction applied to labour element only (not materials)
• ✅ Payment and deduction statement issued within 14 days of tax month end
• ✅ Monthly CIS return submitted to HMRC by the 19th
• ✅ Written subcontractor agreement in place
• ✅ CIS-compatible software in use ahead of MTD changes from April 2026

The Bottom Line

CIS sounds complicated but the process is the same every month once you've set it up properly: verify the subcontractor, make the correct deduction, issue the payment statement, submit the monthly return. Do those four things consistently and you'll stay on the right side of HMRC.

The businesses that run into trouble are usually the ones paying subcontractors informally and sorting the paperwork later — or not at all. In the construction industry, HMRC knows the patterns and investigates accordingly.

If you're building a team, our guide to taking on your first employee as a tradesperson covers the alternative route — and our roundup of the best payroll software for UK trade businesses will help you find the right tool for handling both employees and CIS in one place.

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