Last reviewed: 8 August 2026
Quick summary
- Keep incoming CIS deductions from your customers separate from payments and deductions you make to workers. They answer different tax and compliance questions.
- When paying a subcontractor, HMRC says the contractor starts with the gross invoice, considers permitted material deductions and applies the verified CIS rate. Save the calculation and supporting material evidence.
- Use a tax-month checklist: worker verification, invoice, materials proof, gross payment, CIS deduction, net payment, statement issued and HMRC return/payment status.
Part of Making Tax Digital by business type.
Direct answer
A self-employed person can be a CIS subcontractor when they are paid by a contractor and may also have CIS contractor responsibilities when they pay other subcontractors. Do not merge those roles in one vague “CIS” category. The deductions made from your own invoices are tax withheld from your income. Payments you make to other workers can involve verification, contractor calculations, monthly returns, payment-and-deduction statements and sums paid to HMRC.
For your own Self Assessment and MTD records, start with your gross invoices and retain the monthly statements showing CIS withheld. HMRC's subcontractor guidance says sole traders report full invoice amounts as income and deductions in the CIS-deductions field. For the workers you pay, start with their invoice, the verified status, any relevant materials evidence, the deduction calculation and the net payment. These are different documents, even if the same job produced both.
The employment-status question comes before a neat spreadsheet. CIS registration does not decide whether every worker relationship is self-employment. Where a worker is effectively an employee, different obligations may apply. Put that question in the accountant brief rather than assuming a self-employed invoice solves it.
Build two ledgers, not one construction spreadsheet
Ledger one: work you sold. Track customer or main-contractor name, job, gross labour, materials charged, VAT where relevant, CIS deduction shown on the contractor statement, net bank receipt and any retention. Match the gross invoice to the statement and bank payment. This helps avoid the common error of treating the net payment as turnover.
Ledger two: labour you bought. Track worker name and UTR/verification reference, job, invoice number, gross amount, qualifying materials evidence, rate notified by HMRC, deduction made, net paid, statement issued and the tax-month return reference. Include the date paid, not only the invoice date, because the payment is a key point for the contractor process.
Keep a third, ordinary-expense ledger for materials you bought yourself, plant hire, fuel, tools, insurance and site costs. A worker's material deduction should not become your own materials expense simply because it affects the CIS calculation. Three separated views are more useful than an app that produces one reassuring total with no explanation underneath.
A practical CIS tax-month workflow
Before paying a new worker, check that the written arrangement, work and worker status have been reviewed appropriately, then complete the relevant verification step. Obtain their invoice and request receipts or other proof where they are claiming materials they paid directly for. HMRC's guidance describes deductions from the gross invoice after taking account of VAT and certain materials, consumable stores, fuel and hired plant, subject to the facts.
When you pay, store the calculation with the invoice. Record the gross payment, material amount allowed for the calculation, rate confirmed, CIS deduction, net payment and bank reference. If deductions are made, issue the payment and deduction statement in the required timeframe: HMRC says within 14 days after the tax month ends. Then complete the monthly contractor return and payment obligations on time. If no payments are expected for a period, check HMRC's rules for making a scheme inactive rather than quietly skipping returns.
At month end, reconcile the outgoing CIS ledger to bank payments and the contractor-return total. Separately, reconcile incoming CIS statements against your own sales ledger. This is where an accountant can see whether a deduction has gone missing, a worker's invoice has been paid twice, materials have been counted incorrectly or a customer has failed to issue the statement you need.
Three construction jobs, three record packs
- Bricklayer hires a labourer for one extension: retain the main-contractor statement showing CIS deducted from the bricklayer's own gross invoice, then separately retain the labourer's verification, invoice, payment calculation and statement.
- Kitchen fitter pays a subcontractor who supplied materials: keep the subcontractor's material evidence with the CIS calculation. The amount is not guessed from a verbal split after payment.
- Small contractor uses the same worker every month: keep a new monthly payment trail and statement even though verification was completed earlier. Repeated work is not a reason to stop recording deductions or reviewing status.
The reader here does not merely need another list of CIS rates. They need a job-level route from main-contractor payment, through labour bought, to monthly evidence that proves both sides of the work.
Records to gather
- Gross invoices to main contractors and their monthly CIS deduction statements.
- Customer payment, retention and bank-receipt records.
- Worker contracts or engagement notes, invoices and UTR verification records.
- Materials receipts supplied by workers where they affect the deduction calculation.
- Gross, deduction and net-payment calculations with bank evidence.
- Payment-and-deduction statements issued to workers and monthly return confirmations.
- VAT, reverse-charge or plant-hire documents where relevant to the job.
- Your latest tax return, MTD software records and current accountant correspondence.
Name files by job, worker and tax month. A folder labelled Kitchen refit - May tax month - Jones labour is much easier to audit than a list of phone screenshots and generic PDF invoices.
Common mistakes
Do not deduct CIS from the wrong amount by overlooking VAT or unverified material evidence. Do not record the worker's net payment as the whole cost without preserving the gross invoice and deduction. Do not offset CIS deducted from you against the CIS you deduct from someone else in a casual spreadsheet. And do not wait until January to chase missing incoming deduction statements; HMRC's subcontractor guidance relies on them for your own tax position.
Another common error is treating an agency, labour provider or recurring helper as automatically outside employment considerations. The payment route and label are not the full analysis. Save contracts and facts, then ask a suitable accountant or adviser where the relationship is uncertain.
Questions to take to an accountant
- Do I need CIS contractor registration for the payments I make, and what needs verifying?
- How should I separate incoming CIS deducted from me from outgoing deductions I make?
- Which material amounts can be supported in the worker-payment calculation?
- Are any worker arrangements an employment-status concern rather than ordinary subcontracting?
- How should CIS contractor records feed into my MTD bookkeeping and quarterly review?
- Who will complete the monthly return, issue statements and reconcile missing documents?
Useful related guides
Key takeaway
A CIS subcontractor who pays other workers needs two ledgers: one for gross income and CIS withheld by customers, and one for the worker payments and contractor duties they create. Keep the calculation and evidence at job level, reconcile every tax month and bring both sides of the records to an accountant before errors become annual-return problems.
Official sources checked on 8 August 2026
Frequently asked questions
Can a CIS subcontractor also be a CIS contractor?
A business can receive payments as a subcontractor and make payments to other subcontractors. Keep the roles separately evidenced and check the contractor requirements that apply to its payments.
Are deductions taken from me the same as deductions I make from workers I pay?
No. Incoming deductions are tax withheld from your invoices; outgoing deductions are part of your contractor responsibilities. Keep separate ledgers and statements.
What does a CIS contractor need to give a subcontractor?
HMRC says a contractor that makes deductions must give a payment and deduction statement within 14 days after the end of the tax month.