What the Construction Industry Scheme means for invoicing and cash flow

If you’re a subcontractor in the UK construction industry, you’ll be familiar with the Construction Industry Scheme, or CIS. You also know the confusion it can cause. You send an invoice for one amount, but the payment that lands in your bank account is for a lower figure. This gap can wreak havoc on your cash flow and make reconciling your accounts a real headache.

This guide cuts through the complexity. We'll explain exactly what the CIS deduction on your payment means, how to create invoices that work with the scheme, and most importantly, how to manage your cash flow and accounts when the amount you're paid doesn't match the amount you've billed. This is your practical guide to navigating CIS and getting your finances straight.

What is the Construction Industry Scheme (CIS)?

The Construction Industry Scheme is an HMRC system for collecting income tax and National Insurance contributions from subcontractors working in the construction industry. It’s not an additional tax; it's a way of paying your tax liability in advance, directly from your invoices.

Under the scheme, contractors are required to deduct a percentage from the payments they make to their subcontractors and pay this money directly to HMRC. This deduction acts as an advance payment towards the subcontractor's tax and National Insurance bill.

The primary goal of CIS is to reduce tax evasion within the construction sector. By collecting tax at the source, HMRC ensures that tax is paid on income that might otherwise go undeclared. For the subcontractor, it means a portion of your earnings is sent to the taxman before you even see it, which requires careful financial planning.

Are You a Contractor, a Subcontractor, or Both?

Understanding your role within the scheme is the first step.

• Contractors: A contractor is a business or other entity that pays subcontractors for construction work. This includes mainstream construction companies, but can also include property developers or even businesses in other sectors that have a high annual spend on construction (defined by HMRC as an average of £1 million a year over 3 years). If you pay others for construction work, you are likely a CIS contractor and must register with HMRC.

• Subcontractors: A subcontractor is a business that carries out construction work for a contractor. If you are a self-employed individual, a partnership, or a limited company doing construction work for a larger firm, you are a subcontractor. You don’t have to register for the scheme, but as we'll see, it is highly advisable.

It's common for a business to be both a contractor and a subcontractor. For example, a main building firm might be contracted to build a house (acting as a subcontractor to the developer) and then hire a specialist plasterer and electrician to do parts of the job (acting as a contractor to them). In this case, the business must follow the CIS rules for both the payments it receives and the payments it makes.

The Three CIS Deduction Rates: What Percentage Will Be Taken?

The amount a contractor deducts depends on your registration status with HMRC. There are three possible rates, and the difference between them has a massive impact on your immediate cash flow.

Status	Deduction Rate	Who it applies to
Unregistered	30% (Higher Rate)	Subcontractors who are not registered for CIS with HMRC. This is a punitive rate designed to encourage registration.
Registered	20% (Standard Rate)	Subcontractors who have registered for CIS but do not qualify for gross payment status. This is the most common rate.
Gross Payment Status	0% (No Deduction)	Subcontractors who have registered for CIS and meet strict qualifying criteria. They receive the full invoiced amount.

Why you should register for CIS

Being hit with a 30% deduction is a significant blow to cash flow. Registering for the scheme is straightforward and immediately reduces your deduction rate to 20%. To register as a subcontractor, you'll need your National Insurance number and your Unique Taxpayer Reference (UTR).

Applying for Gross Payment Status (0% Deduction)

Receiving 100% of your invoiced amount without deductions is the ideal scenario for cash flow. To achieve this, you can apply for 'gross payment status'. HMRC will check that you meet three key tests:

1. Business Test: You carry out construction work in the UK and run your business primarily through a bank account.
2. Turnover Test: Your annual business turnover for the last 12 months (excluding VAT and materials) must be at least £30,000 if you're a sole trader, or £30,000 per partner/director for partnerships and companies (up to a maximum of £100,000).
3. Compliance Test: You have a good history of paying your taxes and filing your returns on time.

If you meet these criteria, applying for gross payment status is a powerful way to take back control of your cash flow.

How to Create a CIS-Compliant Invoice: A Step-by-Step Guide

One of the most common points of confusion is what a CIS invoice should look like. A critical rule to remember is this: You do not show the CIS deduction on the invoice you send to the contractor.

Your invoice should show the full, gross amount due for the work. The contractor is responsible for calculating the deduction, making the partial payment to you, and paying the deducted amount to HMRC.

Here’s how to structure your invoice:

1. Include all standard invoice information: Your business name and address, the contractor's name and address, an invoice number, the invoice date, and your payment terms.
2. Clearly separate labour and materials: This is the most important step for CIS. The deduction is only applied to the cost of your labour. Any materials you supplied for the job are excluded from the CIS calculation.
3. Calculate VAT correctly (if applicable): If you are VAT registered, you must charge VAT on the total of both labour and materials. The CIS deduction is calculated on the labour-only portion, before VAT is added.

A Worked Example

Let's imagine you are a CIS-registered subcontractor (20% rate) and you've completed a job. Your invoice should be broken down as follows:

• Labour: £2,000
• Materials purchased for the job: £800
• Subtotal: £2,800
• VAT at 20%: £560
• Total Invoice Amount Due: £3,360

This is the invoice you send to your contractor. They are responsible for the next part.

When they pay you, the contractor will:

1. Identify the labour portion of your invoice (£2,000).
2. Calculate the CIS deduction at 20%: 20% of £2,000 = £400.
3. Pay the remaining balance to you: £3,360 (Total Invoice) - £400 (CIS Deduction) = £2,960.

This £400 is paid directly to HMRC by the contractor on your behalf.

The Cash Flow Crunch: Why Your Bank Balance Doesn't Match Your Invoice Total

The worked example above perfectly illustrates the CIS cash flow trap. You've issued an invoice for £3,360, but you only received £2,960. You are "down" by £400.

This isn't lost money – it's your tax being paid in advance. However, the immediate impact on your working capital is real:

• Covering Costs: You've already spent £800 on materials.
• VAT Liability: You are liable to pay HMRC the £560 of VAT you charged, regardless of whether you've been paid in full.
• Immediate Shortfall: The £400 deduction means you have less cash in hand to cover overheads, wages, and other running costs before you can reclaim it at the end of the tax year.

For businesses operating on tight margins, this constant deduction from every labour invoice can put a serious strain on finances. It's essential to factor this reduction into your cash flow forecasting.

Reconciling CIS Payments in Your Accounts

So, you have an invoice in your accounting software for £3,360, but a payment of only £2,960 has hit your bank. How do you mark the invoice as fully paid without your books being incorrect?

The answer is to use a specific account to track the deductions. All major accounting software packages like Xero, QuickBooks, and Sage have a dedicated process for this. The account is usually called "CIS Suffered" or "CIS Asset".

Here is the typical reconciliation process:

1. Raise the full invoice: In your accounting software, create the invoice for the gross amount of £3,360, as detailed in the example.
2. Match the bank payment: When the £2,960 payment appears in your bank feed, match it against the outstanding £3,360 invoice.
3. Allocate the deduction: Your software will show a remaining balance of £400 on the invoice. Instead of leaving it as unpaid, you'll allocate this remaining amount to your "CIS Suffered" nominal ledger account.

The result? The invoice is now marked as fully paid, your bank is reconciled, and the £400 deduction is correctly recorded as an asset – money that has been paid to HMRC on your behalf and is waiting to be offset against your tax bill.

What is a CIS Payment and Deduction Statement? (And Why You MUST Get One)

The "CIS Suffered" figure in your accounts isn't just an internal number. It needs to be backed up by official evidence from your contractors.

Contractors are legally required to provide you with a payment and deduction statement for every payment they make to you under CIS. This must be issued within 14 days of the end of each tax month.

This statement is your proof. It must show:

• The contractor’s name and reference number.
• Your details.
• The gross amount of the payment(s).
• The total cost of materials that were excluded from the deduction.
• The amount of the CIS deduction.

Keep these statements safe! You will need them to verify the totals in your accounts and as evidence for HMRC when you file your tax return. If a contractor fails to provide you with a statement, chase them for it. They are legally obliged to give you one.

Claiming Your CIS Deductions Back from HMRC

The money sitting in your "CIS Suffered" account throughout the year is not gone forever. At the end of the tax year, you reclaim it.

• For Sole Traders and Partnerships: You declare the total CIS deductions you've suffered on your annual Self Assessment tax return. HMRC will calculate your total income tax and National Insurance liability for the year and subtract the CIS you've already paid. If you've overpaid, you'll receive a tax refund.
• For Limited Companies: The process is slightly different. You can offset your CIS deductions against your company's PAYE and National Insurance liabilities through your monthly payroll submissions. If your CIS deductions are more than your PAYE bill, you can have this offset against your Corporation Tax liability. If there is still a credit remaining, you can claim a refund from HMRC.

Chasing Late Payments Under CIS Rules

CIS can add a layer of complexity to credit control, but the fundamental principle remains the same: you are owed the full, gross amount of your invoice until it is paid.

If a contractor is late in paying your £3,360 invoice, you chase them for the full £3,360. The CIS deduction is only relevant at the moment of payment. The contractor cannot claim they only owe you £2,960; their obligation to pay HMRC the £400 deduction only crystallises when they pay you.

Furthermore, if you need to charge statutory late payment interest and compensation under the Late Payment of Commercial Debts (Interest) Act 1998, you calculate this on the gross invoice total that is overdue (£3,360), not the net amount.

Manually tracking which invoices are overdue, calculating potential interest, and sending reminders is time-consuming. This is especially true when dealing with multiple small-to-medium-sized jobs. For many busy subcontractors and small construction firms, automating this process is a game-changer. An automated system like InvoiceReminder can track invoice due dates and send scheduled reminders for the full, correct amount, ensuring that nothing slips through the cracks while you focus on the actual construction work.

Frequently asked questions

Do I show the CIS deduction on my invoice?

No. You should always invoice for the full gross amount (labour + materials + VAT, if applicable). The contractor is responsible for calculating and withholding the CIS deduction when they pay you. Showing it on the invoice can cause confusion and accounting errors.

What happens if a contractor deducts the wrong amount?

If a contractor deducts the higher 30% rate because they couldn't verify you, but you are registered for the 20% rate, contact them immediately. Provide your UTR and ask them to correct it. They can usually adjust the deduction on their next monthly CIS return to HMRC and refund you the difference.

Can I get paid without any CIS deductions?

Yes. To be paid in full without any deductions, you must apply to HMRC for 'gross payment status'. This requires you to meet specific turnover, business, and tax compliance tests. If approved, contractors can pay you the full invoice amount.

Does CIS apply to the cost of materials?

No. CIS deductions are only calculated on the cost of the labour portion of your services. You must clearly separate the cost of labour and materials on your invoice so the contractor can calculate the deduction correctly.

What if my contractor doesn't give me a payment statement?

Contractors are legally required to provide you with a payment and deduction statement within 14 days of the end of each tax month. If they don't, you should chase them for it as it's your essential proof of deductions. If they persistently fail to provide one, you can report them to the HMRC CIS helpline.

Is CIS an extra tax on top of my normal tax bill?

No. It is an advance payment towards your final income tax (or Corporation Tax) and National Insurance bill. The total amount deducted throughout the year is credited against your total liability when you file your tax return.

Take control of your invoices

Navigating the Construction Industry Scheme is a key part of financial management for any UK subcontractor. By structuring your invoices correctly, planning for the cash flow impact of deductions, and reconciling payments properly, you can stay in control. Chasing those payments, however, is another job entirely.

InvoiceReminder helps small businesses, freelancers, and accountants automate the process of chasing invoices. By connecting to your accounting software like Xero, QuickBooks, FreeAgent, or Sage, it sends scheduled email reminders for overdue payments, so you don't have to. For businesses in the construction sector, this means less time spent on admin and more time focused on delivering projects. The system currently offers a free plan with unlimited email reminders, helping you improve your cash flow at no cost. InvoiceReminder is built by the team behind WeCovr, a UK company authorised and regulated by the Financial Conduct Authority for its insurance activities.