CIS Subcontractor Guide UK 2026: Deductions, Invoicing and Gross Payment Status Explained

What Is CIS and Who Does It Apply To?

The Construction Industry Scheme is a HMRC tax scheme that requires contractors to deduct money from subcontractor payments and pass it directly to HMRC as an advance payment toward the subcontractor's tax and National Insurance bill. The scheme is designed to reduce tax evasion in the construction industry.

CIS applies when a subcontractor does construction work for a contractor. Both parties must be registered with HMRC under CIS. The key points:

• CIS applies to the full range of building trades — electrical, plumbing, roofing, plastering, brickwork, groundwork, joinery and more.
• CIS does not apply to direct-to-homeowner work. If you invoice a homeowner directly for a kitchen fit or rewire, CIS does not come into play.
• CIS applies when your client is a contractor or a business that spends more than £1 million per year on construction work.
• If you are a sole trader, a partnership, or a limited company doing subcontract construction work, CIS likely applies to you.

Both the contractor and subcontractor must register with HMRC before the scheme takes effect. Contractors register via their HMRC online account. Subcontractors register using their Government Gateway account at gov.uk/register-as-subcontractor-cis.

CIS Deduction Rates

The deduction rate depends on your registration status. Contractors verify your status with HMRC before making any payment.

Registering as a CIS subcontractor takes around 10 minutes via your HMRC Government Gateway account. You will need your UTR (Unique Taxpayer Reference) number. Once registered, contractors can verify you and apply the 20% rate rather than 30%.

How to Write a CIS Invoice Correctly

The most important rule for CIS invoicing is simple: separate your labour from your materials. The CIS deduction applies only to the labour element — not materials. A CIS invoice that lumps everything together is wrong and makes it harder for both you and the contractor to calculate the correct deduction.

Here is the correct structure for a CIS invoice:

Your invoice should also include: your name and address, your UTR number, the contractor's name and address, the invoice date, a description of the work, and a unique invoice number for your records.

Sleepless Tradesman generates CIS-compliant invoices automatically — the labour/materials split and deduction calculation is handled for you, so you can send a professional CIS invoice in seconds.

What Materials Are Exempt from CIS Deduction?

Not everything on your invoice is subject to CIS. HMRC specifically exempts certain costs from the deduction calculation. Understanding this means you keep more of what you are owed.

• Materials you directly purchase and supply — if you bought the materials yourself and are passing the cost on to the contractor, those costs are excluded from the CIS deduction.
• Plant hire — hiring scaffolding, tools, equipment and machinery is usually excluded from CIS deductions.
• Fuel and consumables — diesel for a generator, consumables used on site, are generally excluded.
• VAT — VAT is always excluded from the CIS deduction calculation. CIS applies to the net (ex-VAT) labour charge only.

The rule of thumb: if it is a physical item you purchased and supplied, it is generally exempt. If it is time you spent working, it is subject to CIS. If in doubt, err on the side of separating it clearly on your invoice and noting what it is — HMRC guidance supports deducting materials costs from the CIS calculation where they are genuine and verifiable.

Monthly CIS Returns — What Contractors Must Do

As a subcontractor, you do not file monthly CIS returns — that is the contractor's responsibility. The contractor must file a monthly CIS return with HMRC by the 19th of each month, showing all payments made to subcontractors and the deductions taken during the previous tax month.

What you should receive each month is a CIS payment and deduction statement from each contractor. This document shows:

• The gross amount paid
• The amount of any materials included
• The CIS deduction taken
• The net amount you received

Keep every CIS deduction statement you receive. You will need these to complete your self-assessment tax return and claim back any overpaid CIS deductions. If a contractor fails to provide one, you are legally entitled to request it — and they are legally required to provide it.

Claiming Back Your CIS Deductions

CIS deductions are advance payments toward your tax bill — they are not a flat charge that you lose forever. When you complete your annual self-assessment tax return, you declare your total income and the total CIS deductions that were made. HMRC offsets the deductions against your final tax liability.

If your CIS deductions exceed your actual tax liability for the year — which is common for sole traders with significant material costs or deductible expenses — HMRC will refund the difference. Many tradespeople receive CIS refunds of several thousand pounds each year.

The downside is the wait. If you work heavily under CIS, you can be handing over 20% of your labour income every month from April, and not seeing that money back until the following January (when self-assessment payments are typically settled). This is precisely why gross payment status is worth pursuing — it eliminates that 12-month cash flow gap entirely.

Gross Payment Status: How to Apply and Why It Matters

Gross payment status (GPS) is the most valuable CIS benefit available to established subcontractors. With GPS, contractors pay you your full invoice amount — no deduction at source. You settle your tax bill directly with HMRC through self-assessment in the usual way.

To qualify for gross payment status, you must meet all three of HMRC's criteria:

• Trading history: You must have been operating as a subcontractor for at least 12 months.
• Turnover threshold: At least £30,000 net turnover per year (or £100,000 for a company with multiple directors).
• Tax compliance: You must have a clean record — all tax returns filed on time, all payments made on time, no outstanding debts to HMRC.

Apply via your Government Gateway account. HMRC reviews GPS applications and typically responds within a few weeks. Once granted, contractors will verify your GPS status when you give them your UTR and pay you in full.

HMRC reviews GPS status annually. If your compliance slips — a late return, a missed payment — they can revoke it. Maintaining GPS requires keeping your tax affairs in order year-round.

Best Apps for CIS Invoicing in 2026

Managing CIS invoices manually in a spreadsheet is error-prone and time-consuming. A purpose-built invoicing app makes it far easier to get the deduction calculation right every time. Here are the main options for UK trade subcontractors:

For most sole trader subcontractors — an electrician or plumber working under one or two main contractors — the complexity and cost of full accounting software is overkill. A dedicated trade invoicing app that handles CIS formatting correctly is all you need.

Summary: CIS for UK Trade Subcontractors

CIS is unavoidable if you do subcontract construction work in the UK. The three things that matter most:

1. Register with HMRC so you pay 20% rather than 30%.
2. Invoice correctly — always separate labour from materials. Only labour is subject to CIS deduction.
3. Apply for gross payment status once you meet the criteria. The cash flow improvement is significant.

Keep every CIS deduction statement from your contractors, file your self-assessment on time, and use an invoicing tool that handles the CIS calculation for you. Done right, CIS is a manageable part of being a subcontractor — not a source of stress or financial surprise.

Frequently Asked Questions