CIS scheme explained in plain English helps contractors and subcontractors understand how the Construction Industry Scheme works. If you work in construction, pay subcontractors, or get paid by contractors, CIS affects registration, verification, tax deductions, monthly returns, payment statements and how tax is later credited against your bill. Understanding the scheme helps you avoid HMRC problems, protect cash flow and keep construction tax records under control.
About this episode
Explaining the CIS scheme looks at one of the key tax compliance areas for construction businesses.
We explain what the Construction Industry Scheme covers, what contractors and subcontractors are, when registration matters, how deductions work, why verification is important, and how CIS reporting affects sole traders and limited companies.
For the wider self-employed tax picture, our episode on Tax basics for self employed: What You Need to Know is a useful next step.
Why the CIS scheme matters
The construction sector is large, busy and full of contractor-subcontractor relationships. That is one reason CIS exists.
The scheme was introduced to reduce tax evasion in the construction industry. Under CIS, contractors deduct tax from certain subcontractor payments and pass those deductions to HMRC.
Those deductions are not an extra tax in themselves. They are advance payments towards the subcontractor’s tax and National Insurance. However, mistakes with registration, deductions or returns can still lead to penalties, repayment problems and cash flow pressure.
Key points from this episode
What is the CIS scheme?
The Construction Industry Scheme, usually shortened to CIS, is a UK tax scheme for construction work.
It tells contractors how to deal with payments made to subcontractors. In many cases, the contractor must deduct tax before paying the subcontractor and then pass that deduction to HMRC.
That means both sides need to understand their role. The contractor must deduct and report correctly. The subcontractor must register, keep records and claim credit for deductions through the right tax route.
Who is a contractor under CIS?
A contractor is a person or business that pays subcontractors for construction work.
You may also count as a contractor even where construction is not your main trade, if your business spends enough on construction work over the relevant period.
The key point is practical. Once you pay subcontractors for construction work, you may have CIS responsibilities. That means registration, verification, deductions, payment statements and monthly returns.
Who is a subcontractor under CIS?
A subcontractor is a person or business that carries out construction work for a contractor.
That can include individual tradespeople, sole traders, partnerships and limited companies. The episode gives practical examples such as plasterers, electricians and ground workers.
A business can also be both contractor and subcontractor. For example, you may be paid by a main contractor on one job and pay your own subcontractors on another. In that situation, you need to understand both sides of the scheme.
What construction work is covered by CIS?
CIS covers most construction work to permanent or temporary buildings and structures, as well as civil engineering work such as roads and bridges.
Construction work can include site preparation, foundations, access works, demolition, dismantling, building work, alterations, repairs, decorating, and installing systems for heating, lighting, power, water and ventilation.
Cleaning the inside of buildings after construction work can also fall within the scheme.
What work is outside CIS?
Not everything connected with construction falls under CIS.
The episode highlights several exclusions, including architecture, surveying, scaffolding hire with no labour, carpet fitting, making construction materials, delivering materials, and work on construction sites that is clearly not construction work, such as running a canteen or site facilities.
This matters because the wrong classification can lead to incorrect deductions or missing deductions. Where the work sits near the boundary, check the current HMRC guidance before deciding.
CIS registration for contractors and subcontractors
Contractors must register for CIS before they start paying subcontractors under the scheme.
Subcontractors should also register. A registered subcontractor usually suffers deductions at the standard rate. An unregistered subcontractor normally suffers deductions at the higher rate.
Registering correctly helps avoid unnecessary deductions, confusion and future tax-record problems.
Verification before paying subcontractors
Before paying a new subcontractor, a contractor must verify them with HMRC.
Verification tells the contractor whether to pay the subcontractor gross, deduct at the standard rate, or deduct at the higher rate.
This is not a discretionary choice. The contractor must follow the payment status given through the HMRC verification process.
CIS deduction rates
The main CIS deduction rates are:
- 20% for registered subcontractors paid under deduction;
- 30% for unregistered subcontractors or where HMRC tells the contractor to use the higher rate;
- 0% where the subcontractor has gross payment status.
The deduction is an advance payment towards the subcontractor’s tax and National Insurance. It is not the same as PAYE employment, and it does not automatically mean the subcontractor has no further tax to deal with.
What CIS deductions are applied to
One common mistake is assuming CIS only applies to a narrow labour amount and ignoring related payments.
The episode explains that travel, subsistence and accommodation charged under the construction contract can form part of the overall contract value for CIS purposes.
However, current HMRC rules also require care. Contractors normally start with the subcontractor’s gross invoice and then remove items such as VAT and qualifying direct materials before applying the CIS percentage to the remaining amount. Therefore, the correct answer is not “labour only” and not always “the full invoice” either. The calculation must follow the CIS deduction rules.
Materials, travel and accommodation
Materials need careful treatment under CIS.
Where the subcontractor has paid directly for qualifying materials used for the job, those material costs may be excluded from the amount on which CIS is calculated. Evidence matters.
Travel, subsistence and accommodation are different. Where those costs form part of what the subcontractor invoices under the construction contract, they can fall into the CIS calculation. This is one area where mistakes are common, so contractors and subcontractors need proper records.
Gross payment status
Gross payment status means the subcontractor can be paid in full, without CIS deductions being taken at source.
This can help cash flow, but it comes with conditions. HMRC looks at compliance history, business activity, bank account arrangements and turnover tests before granting gross payment status.
Gross payment status does not remove the tax bill. It changes when the tax is paid. The subcontractor still declares income and pays tax through Self Assessment or Corporation Tax, depending on the business structure.
Monthly CIS returns
Contractors normally need to report CIS payments to HMRC each month.
The monthly return shows payments made to subcontractors, whether they were paid gross or under deduction, and the deduction rate used.
Missing returns can lead to penalties. Even nil periods need attention unless HMRC has been told the scheme is inactive for a period.
Payment and deduction statements
Where a contractor makes CIS deductions, the subcontractor needs a payment and deduction statement.
This statement helps the subcontractor prove what was deducted and later claim credit for those amounts.
Poor records can create problems when preparing a Self Assessment tax return, company records or a CIS repayment claim.
How subcontractors recover CIS deductions
CIS deductions are credited against the subcontractor’s tax position.
A sole trader or partner normally claims credit through Self Assessment. A limited company subcontractor may be able to offset CIS deductions against PAYE, National Insurance and other liabilities during the year, with any remaining claim dealt with through the appropriate company process.
This is why monthly CIS statements and clean bookkeeping matter. Without evidence, the deduction may be harder to match, reclaim or offset correctly.
CIS and VAT reverse charge overlap
CIS can also overlap with VAT reverse charge rules in construction.
They are separate rules, but they often affect the same construction businesses. CIS deals with deductions from subcontractor payments. VAT reverse charge deals with who accounts for VAT in certain construction transactions.
Our episode on VAT Reverse Charging in the UK: When It Applies and How to Record It is a useful supporting step where VAT also applies.
CIS checklist for contractors and subcontractors
- Are you a contractor, subcontractor, or both?
- Have you registered in the correct CIS capacity?
- Have you checked whether the work is covered by CIS?
- Have you identified any exclusions before invoicing or deducting?
- Has the contractor verified the subcontractor with HMRC?
- Is the correct deduction rate being used?
- Has VAT been excluded before calculating CIS where relevant?
- Are direct material costs supported by evidence?
- Are travel, accommodation and subsistence being treated correctly?
- Are monthly returns, payment statements and records up to date?
FAQs about the CIS scheme
What is the CIS scheme?
The Construction Industry Scheme is a UK tax scheme where contractors deduct money from certain subcontractor payments and pass it to HMRC as an advance payment towards the subcontractor’s tax and National Insurance.
Who needs to register for CIS?
Contractors must register where they pay subcontractors for construction work. Subcontractors should register to avoid the higher deduction rate. A business can be both contractor and subcontractor.
What are the CIS deduction rates?
The usual rates are 20% for registered subcontractors, 30% for unregistered subcontractors, and 0% where the subcontractor has gross payment status.
Does CIS apply to materials?
CIS calculations need care. Contractors usually start with the gross invoice, remove VAT and qualifying direct material costs, then apply the CIS rate to the remaining amount. Evidence for materials matters.
Episode Timecodes
- 00:00 – Construction sector size and why CIS exists
- 00:23 – What the episode covers
- 01:09 – Financial awareness and tax compliance context
- 01:32 – What counts as a contractor
- 02:04 – What counts as a subcontractor
- 02:21 – Registering as contractor, subcontractor, or both
- 03:20 – Construction work covered by CIS
- 03:45 – Repairs, decorating and installation work
- 04:02 – CIS exclusions and non-construction site work
- 04:41 – CIS deductions and tax collector role
- 05:26 – 20%, 30% and gross payment status
- 05:55 – Invoices, VAT and common deduction mistakes
- 06:44 – Travel, subsistence and accommodation
- 07:04 – Gross payment status explained
- 08:23 – Offsetting CIS suffered and CIS deducted
- 08:49 – Limited company treatment
- 09:14 – Sole trader treatment through Self Assessment
- 09:34 – Final recap: rates, verification and monthly returns
Related episodes
- Tax basics for self employed: What You Need to Know
- Tax Treatment for Sole Traders Explained
- VAT Reverse Charging in the UK: When It Applies and How to Record It
Key takeaway
The CIS scheme is a practical tax system for construction work. Contractors need to register, verify subcontractors, apply the correct deduction rate, file monthly returns and give deduction statements. Subcontractors need to register, keep records and make sure deductions are credited properly.
The biggest mistake is treating CIS casually. The scheme affects cash flow, tax records, invoices, monthly reporting and HMRC compliance. Good bookkeeping and clear CIS processes make the whole system easier to manage.
Plan it, Do it, Profit.
“CIS is not just construction paperwork. It affects how subcontractors are paid, how tax is deducted and how records are reported to HMRC.”
Further Support
The I Hate Numbers podcast helps business owners understand tax, CIS, VAT, Self Assessment, payroll, bookkeeping, accounting and business finance in a practical way. We simplify financial topics so you can make better decisions and feel more confident with your numbers.
If you need support with CIS registration, subcontractor verification, CIS deductions, monthly returns, bookkeeping or construction tax records, you can contact us for an initial chat.
You can also watch more practical finance and tax support on the I Hate Numbers YouTube channel, or listen and follow on Apple Podcasts.
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