A subcontractor has finished a job, sent over their invoice and is waiting to be paid. Before you press send, you need to know whether a CIS deduction applies, what rate to use and what paperwork they need from you. That is where people often ask: what is CIS payroll?
CIS payroll is the everyday term for managing payments to construction subcontractors under HMRC’s Construction Industry Scheme, or CIS. It is not payroll in quite the same way as paying an employee through PAYE, but it involves similar responsibilities: checking records, making deductions where required, reporting to HMRC and paying people accurately and on time.
For a busy construction business, getting this right means fewer worries about penalties, disputes with subcontractors and last-minute admin. It also gives everyone a clearer view of what has been paid and what tax has already been deducted.
What does CIS payroll mean?
Under CIS, contractors deduct money from a subcontractor’s payments and pass it to HMRC. Those deductions count towards the subcontractor’s tax and National Insurance bill. The scheme applies to construction work, including many building, decorating, demolition, repairs and installation activities.
A contractor can be a sole trader, partnership, limited company or another type of business. You may be treated as a contractor if you pay subcontractors for construction work. Some businesses outside the construction industry can also be caught by CIS if they spend a substantial amount on construction over a set period.
When people refer to CIS payroll, they usually mean the full monthly process of verifying subcontractors, calculating deductions, issuing deduction statements and submitting the required return to HMRC. If you also employ staff, your business may run PAYE payroll and CIS alongside one another. They are connected in administration but follow different rules.
CIS deductions explained in plain English
Before making a first payment to a subcontractor, a contractor normally needs to register for CIS and verify that subcontractor with HMRC. Verification confirms the person or business is registered and tells you which deduction rate to apply.
There are three common outcomes. A subcontractor may be paid gross, meaning no CIS deduction is made. This is usually for subcontractors who have been granted gross payment status by HMRC. Most registered subcontractors have a 20% deduction rate. If they are not registered, the deduction rate is generally 30%.
The deduction is not always taken from the full invoice total. It is calculated on the labour element, plus certain other amounts, after qualifying materials have been excluded. VAT is not included in the calculation. This is one reason why clear invoices matter. If labour and materials are bundled together without detail, it can be harder to work out the correct deduction and explain it later.
For example, if a verified subcontractor invoices £1,000 for labour and £200 for materials, a 20% CIS deduction is generally calculated on the £1,000 labour figure. The contractor pays £1,000 in total: £800 to the subcontractor and retains £200 to send to HMRC as part of their CIS liability.
That £200 is not an extra cost to the contractor. It is tax withheld from the subcontractor’s payment. The contractor’s responsibility is to calculate, report and pay it correctly.
What subcontractors need to receive
Each time you make a CIS deduction, you must provide the subcontractor with a deduction statement. This confirms the gross payment, the materials amount where relevant, the deduction made and your details as contractor.
Subcontractors need these statements to claim credit for deductions against their tax bill. Missing or inaccurate statements can create unnecessary problems at year end, particularly for sole traders who need to complete a Self Assessment tax return.
Who should be treated as a subcontractor?
This is one of the areas where a quick assumption can cause trouble. Calling someone a subcontractor or asking them to submit an invoice does not automatically make them self-employed for tax purposes.
Employment status depends on the reality of the working arrangement. HMRC may consider factors such as who controls the work, whether the worker can send a substitute, who provides equipment, whether they work for other clients and whether they carry financial risk. A person may need to be on PAYE payroll even if they prefer to be paid as a subcontractor.
This matters because CIS does not replace PAYE. If someone is an employee, you must deal with PAYE tax, National Insurance, workplace pension duties and payslips in the normal way. Construction businesses often use a mix of employees and genuine subcontractors, so it is worth reviewing each arrangement rather than applying one approach to everyone.
Your monthly CIS responsibilities
CIS administration works best when it is built into your payment routine, not left until the end of the month. You need to keep records of payments, deductions, materials and verification details for every subcontractor.
A CIS monthly return tells HMRC what you have paid to subcontractors and what deductions you have made. It is usually due by the 19th of the following tax month. If no payments have been made, you may still need to tell HMRC that no return is due for that period.
The deductions are then paid to HMRC, generally alongside any PAYE and National Insurance liabilities. For many businesses paying electronically, the deadline is the 22nd of the following tax month. Timing can vary depending on how you pay and your circumstances, so a reliable diary process is essential.
Late returns and late payments can lead to penalties and interest. More practically, falling behind makes the next month harder. A few incomplete invoices or unverified workers can soon turn into a time-consuming reconciliation exercise.
Common CIS payroll mistakes to avoid
Most CIS issues are avoidable, but they tend to happen when site work is busy and paperwork arrives late. The following mistakes are especially common:
- Paying a new subcontractor before verifying them with HMRC.
- Applying a 20% rate because it was used previously, rather than checking the current verification result.
- Deducting CIS from materials or VAT when it should only be taken from the relevant payment amount.
- Forgetting to issue deduction statements to subcontractors.
- Missing the monthly return because no one has confirmed what was paid that month.
- Treating workers as subcontractors without properly considering employment status.
There can also be confusion around the domestic reverse charge for VAT. This is separate from CIS. A single construction invoice may need both CIS and VAT treatment considered, but one rule does not replace the other. That is exactly the kind of detail where taking advice before payment is far easier than correcting records later.
Can payroll software handle CIS?
Many payroll and accounting systems can support CIS records, calculations and reporting. Software is helpful, particularly where you make regular payments to several subcontractors, but it can only work from the information you give it.
You still need the correct worker details, a valid verification result, invoices that separate labour and materials, and someone who understands when a payment falls within the scheme. Software will not decide whether a worker is genuinely self-employed or spot an unclear invoice unless the process around it is sound.
For small firms, the right approach depends on volume and confidence. If you pay one or two regular subcontractors and are comfortable with the rules, a well-organised digital process may be enough. If you are managing a growing team, different deduction rates or a mixture of PAYE employees and subcontractors, outsourced support can remove a significant monthly burden.
How CIS payroll support can help
Good CIS support is not just about filing a return on time. It should make the whole process feel more manageable. That can include helping you set up as a contractor, verifying subcontractors before their first payment, checking deduction calculations, preparing monthly returns and providing the statements subcontractors need.
It also means having someone to ask when a situation is not straightforward. Perhaps a subcontractor has changed from sole trader to limited company, an invoice includes a large materials element, or you are unsure whether a new worker belongs on PAYE. A calm conversation at that point can prevent a much bigger problem later.
At Angel Bookkeeping & Payroll Services, the aim is to take this kind of financial admin off busy business owners’ shoulders while keeping the information clear and accessible. You remain in control of your business, without having to become an expert in every HMRC process.
If CIS is taking up more time than it should, start by gathering your recent subcontractor invoices, verification details and payment records. A clear review of those basics can turn a stressful monthly task into a process you can rely on.