Managing Subcontractors: A Practical Guide

There comes a point where you can't take on more work alone. Bringing in subcontractors is the obvious answer — but get it wrong and you'll be chasing other people's mistakes, fielding angry customer calls, and discovering the taxman has questions about how you've handled their pay. This guide covers the practical side of using subcontractors well, so they make your business bigger instead of harder to run.

Subcontractor or employee? Get the status right

Before anything else, be clear on what a subcontractor actually is. A genuine subcontractor runs their own business, invoices you, uses their own tools, can send a substitute, and works for other firms too. An employee turns up when you tell them, uses your kit, and depends on you for their income.

This matters because HMRC cares a great deal about the difference. Treating someone as a subcontractor when they're really an employee can land you with back-dated tax, National Insurance and penalties. The rules around employment status and IR35 change, and the line is genuinely grey in places — so check the current official guidance, or speak to an accountant, before you decide.

Tip: if you're directing someone's hours, supplying all their materials and they only work for you, ask yourself honestly whether they're really self-employed. Getting this wrong is expensive.

Understand CIS before you pay anyone

If you're in construction, the Construction Industry Scheme almost certainly applies. As a contractor paying subcontractors, you may need to:

• Register with HMRC as a contractor
• Verify each subcontractor before their first payment
• Deduct the correct amount from their labour (commonly 20% for registered subbies, 30% for unverified) and pass it to HMRC
• Send the subcontractor a payment and deduction statement each month

CIS only applies to labour, not materials, so your paperwork needs to separate the two cleanly. It's an area people get wrong constantly. Our guide on how CIS deductions work breaks the mechanics down in more detail — read it before your first subbie payment, not after.

Put the agreement in writing

A handshake is not a contract you can rely on when a job goes sideways. Even a simple written agreement protects both sides and prevents the "but you said" arguments that poison working relationships.

A workable subcontractor agreement should cover:

• The scope of work and what "finished" looks like
• Day rate or price, and exactly when and how they get paid
• Who supplies materials, and how those are charged
• Insurance requirements — they need their own public liability cover
• Standards expected, including snagging and putting defects right at their own cost
• Health and safety responsibilities on site

You don't need a solicitor for every job, but a standard template you reuse is worth its weight in gold. If you're weighing up how to pay them, day rate vs price work is worth a read — the same logic applies whether you're paying or being paid.

Check the paperwork upfront — every time

The fastest way to get burned is to assume a subcontractor is qualified, insured and compliant. Verify it. Before they set foot on site, collect and store:

• Proof of relevant qualifications and competence cards
• Their own public liability insurance certificate
• Gas Safe, NICEIC/NAPIT or other scheme registration where relevant
• UTR number for CIS purposes
• Any required RAMS for the work

Keep copies somewhere you can actually find them when a customer, main contractor or auditor asks. Scrabbling through a glovebox or a WhatsApp thread the morning of an inspection is no way to run a business. A job-management system lets you attach certificates and insurance documents to each subcontractor or job, so they're a tap away when you need them — far better than paper job sheets and scattered messages.

Schedule and brief them so nothing gets dropped

Subcontractors aren't mind readers. A vague "can you sort the second fix Tuesday" leads to wrong materials, missed access, and a wasted day everyone pays for.

Give each subbie a clear brief: the address and access details, the customer's name and number, the exact scope, the materials situation, and when you need it done by. The clearer the handover, the fewer the call-backs.

This is where running everything in one place earns its keep. With a job-management platform like Gaffer, you can assign a job to a subcontractor, attach the spec and photos, and the details land on their phone — no double-booking, no "which house was it again?", and a record of who was sent where. If you're still coordinating a team you can't physically see, our guide on managing a field team you cannot see is a good companion piece.

Keep control of quality and the customer relationship

To your customer, the subcontractor is your business. Their tidy-up, their manner, their workmanship all reflect on you. So don't go fully hands-off.

• Set the standard in writing and inspect the work before you sign it off
• Make snagging the subbie's responsibility, agreed upfront
• Keep the customer-facing communication coming from you, not a stranger turning up unannounced
• Get sign-off and a review while the job is fresh

Good subcontractors are worth keeping. Pay them fairly and promptly, give them clear work, and treat them with respect — and they'll prioritise you over the contractor who messes them about. Which brings us neatly to the thing that ruins most subbie relationships.

Pay them properly — and protect your own cash flow

Nothing loses you a reliable subcontractor faster than late or messy payments. But you also can't pay out before your customer has paid you, or your cash flow falls over.

The fix is to structure your own payments so the money flows in the right order. Take deposits and staged payments from customers, invoice promptly on completion, and chase late payers with a proper system rather than awkward phone calls. The faster you get paid, the easier it is to pay your subbies on time — and being known as someone who always pays on the dot is a genuine competitive advantage when good labour is scarce. Our guide on getting paid faster covers the levers that matter most.

Automated invoicing and payment reminders take this off your plate entirely, so the admin around subbie work doesn't eat your evenings.

FAQs

Do I need to register for CIS to use subcontractors?

If you're a contractor in the construction industry paying subcontractors for construction work, you usually need to register for CIS and verify subbies before paying them. The rules have exceptions, so check the current HMRC guidance or ask your accountant about your specific setup.

What's the difference between a subcontractor and an employee?

A genuine subcontractor runs their own business, invoices you, supplies their own tools and can work for others; an employee depends on you, works the hours you set and uses your equipment. HMRC looks at the reality of the arrangement, not just the label you give it, so get the status right.

Should I make subcontractors carry their own insurance?

Yes. Insist on seeing a current public liability certificate before any subcontractor starts, and keep a copy on file. It protects you if something goes wrong and is often a condition of your own cover and any main contractor's requirements.

How do I keep control of quality when someone else does the work?

Set written standards, inspect the work before sign-off, make snagging the subcontractor's responsibility, and keep customer communication coming from you. To the customer the subbie represents your business, so never go completely hands-off.