Home / Insights / CIS records checklist

CIS records checklist: what contractors and subcontractors should keep tidy.

Construction Industry Scheme records can affect cashflow, tax returns, company accounts and HMRC queries. The safest habit is to keep deduction evidence, invoices and expense records together throughout the year.

General guidance only — CIS treatment depends on role, contract facts, verification status and current HMRC rules.

Short answerSubcontractorsContractorsRed flagsFAQs
CIS record routine

The short answer

CIS records need to show who did the work, who paid whom, what was deducted, whether the payment included labour or materials, and how the figures connect to the bank, invoices, tax return, payroll or year-end accounts.

For subcontractors, the biggest risk is relying on bank receipts alone and losing the deduction statements that explain why the payment received was lower than the invoice. For contractors, the risk is paying subcontractors without a clean verification, deduction and monthly-return trail.

Useful principle: treat every CIS payment as a small evidence pack: invoice, payment, deduction statement, materials support where relevant, and a note if the transaction is unusual.

Why this matters commercially

Messy CIS records do not only create tax-return stress. They can hide whether jobs are profitable, whether materials are being recovered correctly, whether cashflow is being squeezed by deductions, and whether a contractor has enough evidence if HMRC asks questions later.

A simple monthly CIS rhythm

  1. Match every contractor payment or subcontractor payment to an invoice.
  2. Save deduction statements before email chains and portals become hard to search.
  3. Separate labour, materials and VAT evidence where relevant.
  4. Keep subcontractor verification and return evidence in one place if you act as a contractor.
  5. Flag missing statements, unexpected deductions or payments that do not match the invoice while the work is still recent.
If you are a subcontractor

Keep evidence for the tax already deducted and the costs still to claim.

Income and deductions

  • Sales invoices issued to contractors.
  • Monthly payment and deduction statements.
  • Bank receipts that match the net amount received.
  • Notes for retentions, part payments or corrected deductions.

Costs and materials

  • Materials receipts and supplier invoices.
  • Tools, equipment, PPE and consumable records.
  • Van, mileage, fuel, parking and travel evidence.
  • Insurance, phone, software and professional-fee records.

Year-end review points

  • Missing deduction statements from any contractor.
  • Payments received personally rather than through the business account.
  • Mixed-use costs that need a sensible business-use note.
  • Whether CIS deductions cover the actual tax position or leave extra tax to plan for.
If you pay subcontractors

The contractor trail must show verification, deduction logic and monthly return evidence.

Contractors need more than supplier invoices. The record should explain how subcontractors were checked, how deductions were calculated, what was reported, and what was paid over.

Before paymentKeep subcontractor details, verification results and the basis for treating the worker as a subcontractor rather than an employee.
At paymentKeep invoices, labour/material splits, deduction calculations, payment dates and deduction statements issued to subcontractors.
After month endKeep monthly return evidence, HMRC payment records and notes explaining nil returns, corrections or disputed amounts.
Before year endReconcile subcontractor costs to bank payments, returns and accounts so missing evidence is not discovered at filing time.
Ask early

CIS red flags worth raising before the deadline.

The payment does not match the invoice

It may be a CIS deduction, retention, contra charge, VAT issue, part payment or mistake. Keep the statement and ask while the contractor can still explain it.

Materials and labour are mixed together

Where CIS applies, the split between labour and materials can matter. Keep supplier evidence and avoid leaving the accountant to guess from a single total.

Subcontractors are paid without a clean process

Verification, deduction statements, monthly returns and employment-status questions should be handled before the pattern becomes hard to defend.

Useful next reads

Connect CIS records to the wider accounting picture.

Bookkeeping records checklist

Use the monthly records checklist to keep bank, receipts and document evidence tidy.

Read the checklist

VAT, payroll and compliance

CIS often sits alongside VAT, payroll, PAYE routines or subcontractor admin, so the systems should be reviewed together.

See compliance support

Cashflow and tax set-aside

CIS deductions affect timing, but they do not remove the need to plan for VAT, Corporation Tax, Self Assessment or payroll liabilities.

Read the cashflow guide

CIS FAQs

Questions that often create avoidable back-and-forth.

Is the deduction statement enough for my tax return?

It is important evidence, but it is not the whole record. You also need invoices, bank records and cost evidence so income and expenses can be reviewed properly.

What if a contractor has not sent a deduction statement?

Ask for it promptly and keep a note of the request. Bank receipts alone may not clearly show the gross income, deduction and net payment.

Does CIS mean I do not need to save for tax?

Not necessarily. CIS deductions may reduce the final bill, but the overall position depends on profit, expenses, business structure, VAT, payroll and other income.

Next step

Use a review before CIS records turn into a year-end reconstruction job.

A focused review can check deduction evidence, subcontractor records, VAT/payroll overlap and the bookkeeping routine that supports the final accounts or return.

Start the tax review check

No pressure, no jargon — just a practical first conversation about where you are now and what needs attention.

Book the review
Start Fit Check