CIS deductions suffered can make a perfectly correct customer payment look short. A subcontractor might raise a £10,000 labour-only invoice, have £2,000 deducted under the Construction Industry Scheme and receive £8,000 in the bank. If the bookkeeping records only the £8,000 receipt, income can be understated and the £2,000 tax deduction can disappear from the accounts.

The useful question is not simply, “How much did the contractor pay me?” It is, “Can I show the full invoice, the amount deducted under CIS, the net cash received and how that deduction is being dealt with?” Good bookkeeping for CIS deductions suffered should connect all four without treating the deduction as a normal business expense.

What CIS deductions suffered actually means

The phrase the term is commonly used in bookkeeping to describe amounts deducted from payments made to a subcontractor under the Construction Industry Scheme. HMRC describes these as deductions contractors make from subcontractor payments. They count as advance payments towards the subcontractor’s tax and National Insurance position rather than reducing the value of the work performed.

For registered subcontractors, the standard deduction rate is normally 20%. HMRC’s current CIS contractor guidance also states that the higher rate is 30% for unregistered subcontractors and that subcontractors with gross payment status can be paid without a CIS deduction.

This is why CIS deductions suffered need their own bookkeeping trail. The customer may pay less cash than the invoice value, but that does not automatically mean the invoice was reduced or partly unpaid.

Your £10,000 invoice can legitimately produce an £8,000 bank receipt

Take a simplified example. A registered subcontractor raises a £10,000 invoice consisting entirely of labour that is subject to the standard 20% CIS deduction, with no VAT or excluded materials in this example. The contractor deducts £2,000 and pays £8,000.

The bookkeeping for CIS deductions suffered should still preserve the £10,000 income. The £8,000 bank receipt clears part of the customer balance and the £2,000 CIS deduction clears the rest into an appropriate CIS suffered control account.

If only £8,000 is posted as sales because that is what reached the bank, turnover is understated. If the £2,000 is posted as an ordinary expense, the accounts can also misrepresent what happened. The deduction is not a cost of earning the income in the same way as materials or subcontractor labour.

Your wider construction bookkeeping may also need to deal with subcontractors paid, reverse-charge VAT, retentions, materials and project costs. This article is deliberately narrower: it focuses on the bookkeeping and reconciliation of CIS deductions suffered by a subcontractor.

CIS deductions suffered should be matched to payment and deduction statements

When a contractor makes a CIS deduction, HMRC requires the contractor to give the subcontractor a payment and deduction statement within 14 days of the end of the relevant tax month. The statement provides the evidence needed to understand how the payment was calculated.

A good CIS reconciliation process should match three things: the sales invoice, the contractor’s payment and deduction statement, and the net amount received in the bank. If those three do not agree, the difference should be investigated while the job and payment are still recent.

The statement is particularly important because the bank transaction alone does not prove how much CIS was deducted. A £7,800 receipt could reflect CIS, a retention, a disputed amount, another deduction or a combination of movements. The supporting statement explains what the contractor actually reported as CIS.

Do not treat every short payment as CIS deductions suffered

A contractor paying less than the invoice total does not automatically create a CIS deduction. Construction payments can also be reduced by retentions, agreed contra charges, disputed work, credits or other contractual adjustments.

That distinction matters because the bookkeeping treatment can be very different. A genuine CIS deduction is supported by the payment and deduction statement. A retention may remain receivable until the contractual conditions for release are met. A disputed amount may require a credit note or further commercial discussion.

Posting every short payment to the CIS control account simply makes the bank reconcile while creating an unsupported tax balance. The source document should determine what the difference represents.

CIS is not normally calculated on the whole invoice

One reason CIS deductions suffered can be difficult to reconcile is that the deduction may not be 20% of the invoice total. HMRC says a contractor starts with the gross amount and removes certain items before applying the CIS percentage, including VAT and qualifying amounts for materials paid for directly by the subcontractor, together with other specified exclusions.

HMRC’s detailed CIS 340 guidance lists the amounts that can be taken out before the percentage is applied. That is why a £10,000 invoice does not automatically mean a £2,000 deduction.

For CIS deductions suffered, the bookkeeper should use the actual contractor statement rather than estimating the deduction from the bank receipt. Where labour, materials and VAT are separated clearly on the invoice, the reconciliation becomes much easier to follow.

VAT and CIS deductions suffered are separate issues

CIS and VAT affect different parts of a construction transaction. CIS determines whether part of the payment is withheld and paid to HMRC on behalf of the subcontractor. VAT determines the VAT treatment of the supply.

Where ordinary VAT is charged, HMRC excludes VAT from the amount on which the CIS deduction is calculated. Construction businesses may also encounter the domestic reverse charge, which can change who accounts for VAT without changing the underlying need to record CIS deductions suffered correctly.

The detailed VAT treatment depends on the supply, VAT status and contractual facts. Where that treatment is uncertain, it should be confirmed with an appropriately qualified tax or VAT adviser rather than inferred from the CIS deduction.

CIS deductions suffered should not leave customer invoices looking overdue

A common bookkeeping problem occurs when the £8,000 bank receipt is matched against a £10,000 invoice but the £2,000 CIS deductions suffered entry is never posted. The accounting system then continues showing £2,000 as an overdue customer balance.

The customer may have paid exactly what was required under CIS, yet the aged receivables report says they still owe money. Credit control may then chase a contractor for an amount that was legitimately deducted and reported to HMRC.

The solution is not to write off the £2,000 as a bad debt. The payment statement should be used to post the CIS deduction so the invoice is settled in full while the deducted tax remains visible in its own control account.

Bank reconciliation alone will not fix CIS deductions suffered

The business bank account can reconcile perfectly while the CIS balance remains wrong. The £8,000 deposit is genuinely in the bank, so matching that cash movement does not prove that the £10,000 sales invoice has been accounted for correctly.

This is why ordinary bank reconciliation and customer-ledger reconciliation need to work together. The bank confirms the cash received. The customer account confirms which invoice the payment settles. The CIS control account explains the amount withheld by the contractor.

If all three balances make sense, the transaction has a much stronger audit trail than simply marking the bank-feed line as income.

Sole traders should record the full invoice, not the net payment

HMRC’s guidance for CIS subcontractors says sole traders and partners should record the full amounts on their invoices as income and enter deductions made by contractors in the CIS deductions field of their Self Assessment return.

That makes the bookkeeping treatment of CIS deductions suffered particularly clear for a sole trader. The gross invoice is still income. The deduction is recorded separately so it can be reflected in the eventual tax calculation.

The bookkeeping should therefore retain the monthly statements throughout the year rather than attempting to recreate an annual CIS total from bank receipts shortly before the Self Assessment deadline.

Limited companies deal with CIS deductions suffered differently

A limited company that has CIS deductions suffered should not assume the recovery process is the same as for a sole trader. HMRC states that a company paid under deduction claims those amounts back through its monthly payroll scheme rather than through its Corporation Tax return.

HMRC’s current limited-company CIS guidance explains the repayment process, while CIS 340 confirms that companies use the Employer Payment Summary process to set deductions against relevant employer liabilities. The amount can then be set against PAYE and National Insurance liabilities in accordance with HMRC’s process.

This means the bookkeeping for CIS deductions suffered needs to connect with payroll records as well as sales and bank reconciliation. The CIS control balance should not simply accumulate for twelve months with no comparison to the amounts reported through payroll.

The detailed payroll claim should be completed or reviewed by the person responsible for the company’s PAYE and CIS reporting. The bookkeeper should make sure the underlying statements and ledger balances support what is being claimed.

Do not claim CIS deductions suffered from the wrong period

Timing is important because contractor payment statements are based on payments made within CIS tax months. An invoice date, payment date and accounting month do not always fall in the same period.

For CIS deductions suffered, the safest monthly process is to use the contractor statement and actual payment date rather than assuming the deduction belongs to the month in which the sales invoice was raised.

This is especially important for limited companies reporting year-to-date deductions through payroll. A timing mismatch between the accounting record and the statements used for the EPS can create a balance that appears to be missing or duplicated.

Missing CIS statements should be chased promptly

If a contractor has deducted CIS but the statement is missing, the bank receipt may suggest the approximate amount, but that is not the same as having evidence of the deduction.

HMRC says subcontractors can ask contractors for replacement copies of missing statements. If the contractor has stopped trading and the statements cannot be obtained, HMRC’s guidance explains what information the subcontractor can provide to HMRC.

A monthly document check is therefore better than discovering missing statements at year end. The person who dealt with the contractor is more likely to remember the job, payment and contact details while they are current.

CIS deductions suffered should be reconciled by contractor

When a subcontractor works for several contractors, one total CIS control balance is not always enough to understand the position. A supporting schedule can show CIS deductions suffered by contractor and tax month.

That makes it easier to compare the accounting system with payment statements, identify a missing month and respond if HMRC asks for evidence supporting a claim. It also prevents one contractor’s overstatement from being hidden by another contractor’s missing deduction.

The accounting software does not necessarily need a separate nominal account for every contractor. The customer ledger, statement attachments and a well-maintained reconciliation schedule can provide the detail without making the chart of accounts unnecessarily complicated.

Check that CIS deductions suffered are not duplicated

Duplicate recording can happen when a bookkeeper posts CIS deductions suffered from the contractor statement and later imports the same amount through a payroll journal or year-end adjustment.

The control account may then show twice the tax actually deducted. If the duplicate is not noticed, the business could compare an incorrect bookkeeping balance with its Self Assessment or payroll records.

Good bookkeeping habits include reviewing unusual balance-sheet accounts regularly rather than waiting for the accountant to discover an old balance at year end. The CIS suffered account should be one of those reviewed balances for a construction subcontractor.

Retentions must be kept separate from CIS deductions suffered

Construction contracts often allow part of the amount due to be retained until a later stage. A retention is not the same thing as the CIS deduction, even though both can reduce the cash received now.

Suppose an invoice includes work subject to a contractual retention and the contractor also deducts CIS from the amount being paid. The bookkeeping may need to show the amount currently payable, the retention still receivable, the CIS deduction and the net bank receipt separately.

Combining the retention and CIS into one “short payment” category makes both the debtor balance and the tax-control balance less reliable. The contractor statement and contract information should provide the evidence needed to distinguish them.

CIS deductions suffered can distort turnover if the bank feed is trusted blindly

Bank-feed automation often sees only the net cash. If a rule categorises every contractor receipt directly to sales, CIS deductions suffered may never be recorded and turnover can be understated repeatedly.

This error becomes more serious as transaction volume grows because the bookkeeping can look tidy. Every bank line is categorised and the bank account may reconcile, yet the profit and loss account contains only net receipts instead of the full income earned.

The control is to match customer receipts against sales invoices rather than create new income from the bank line. The CIS deduction then settles the remaining part of the invoice through the appropriate control account.

7 proven checks for CIS deductions suffered

  1. Start with the full sales invoice. Confirm the gross value of the work and keep labour, materials and VAT clearly identifiable.
  2. Obtain the contractor statement. Do not estimate the CIS amount solely from the amount missing from the bank payment.
  3. Match the net receipt to the bank. Confirm the amount and date actually paid by the contractor.
  4. Settle the customer invoice correctly. Use the bank receipt plus the genuine CIS deduction so the ledger does not show a false overdue balance.
  5. Reconcile the CIS control account. Compare the bookkeeping total with payment and deduction statements by contractor and tax month.
  6. Check the recovery route. Sole traders and partnerships deal with deductions through Self Assessment, while limited companies generally use the payroll and EPS process described by HMRC.
  7. Review remaining differences. Separate retentions, disputed amounts, credits and timing differences from genuine CIS deductions suffered.

These checks provide a clear route from the invoice to the statement, the bank and the eventual tax or payroll record.

What records should support CIS deductions suffered?

A clean monthly file should make the deductions easy to prove without reconstructing the position later.

The aim is not paperwork for its own sake. It is to make the deducted amount traceable from the customer transaction through to the records used for tax or payroll reporting.

Why monthly CIS deductions suffered reconciliation is better than year-end clean-up

Construction businesses can accumulate dozens of deduction statements over a year. If CIS deductions suffered are reviewed only at year end, missing statements, mismatched invoices and old retentions become much harder to resolve.

A monthly review catches the issue while the contractor, job and payment are still familiar. The bookkeeper can request a missing statement, investigate a difference and keep the customer ledger current without leaving months of false overdue balances.

It also gives the accountant a much cleaner year-end starting position because the CIS balance has already been tied back to supporting records rather than presented as one unexplained figure.

When CIS deductions suffered become a bookkeeping warning sign

A small subcontractor with one contractor and a handful of payments may find the process straightforward. The warning signs appear when several contractors are involved, statements are missing, retentions are common or the accounting system contains a large unexplained CIS asset balance.

Another warning sign is when the owner knows roughly how much the CIS suffered total should be but cannot produce a contractor-by-contractor reconciliation. That can create difficulty when the accountant, payroll provider or HMRC needs evidence behind the total.

Regular bookkeeping services can keep invoices, bank receipts, contractor statements and control accounts aligned throughout the year. Where the entire recurring process needs to be handed over, outsourced bookkeeping can provide regular processing and reconciliation within an agreed scope.

CIS deductions suffered should explain the missing-looking money

The important point is that CIS deductions suffered do not make part of a genuine invoice disappear. They explain why the subcontractor can earn one amount and receive a lower cash payment from the contractor.

A good set of books should show the full invoice, the amount deducted, the net bank receipt and the route by which the deduction is reflected in the subcontractor’s tax or payroll records. If one of those pieces is missing, the transaction is not fully reconciled.

If contractor payments keep arriving short of the invoices and the CIS balances no longer agree with the statements, you can contact Bookkeeping Packages Ltd to discuss the current records and the bookkeeping work needed to reconcile them.

About the Author

Stuart Kerr is Managing Director of Bookkeeping Packages Ltd, an outsourced bookkeeping service supporting UK small businesses and accountancy practices. With over 20 years of bookkeeping experience, Stuart specialises in helping businesses maintain reliable financial records and useful management information.

This article is provided for general information only. Stuart Kerr is a professional bookkeeper, not a regulated financial adviser. Nothing in this article constitutes tax, legal or financial advice. Advice specific to your circumstances should be obtained from an appropriately qualified professional.