Historically, the Construction Industry Scheme has been a subject of interest to tax authorities in the UK. Due to the scale of the industry, prevalence of undeclared income and serious compliance issues, it comes as no surprise that HMRC continues to emphasise compliance in this sector, including new measures (effective from 6 April 2026) giving HMRC stronger powers to tackle fraud where businesses knew (or should have known) a payment was connected to tax evasion.
Over time, incidences of tax evasion and compliance failures have prompted HMRC to tighten CIS rules and introduce new legislation, including stronger anti‑fraud measures due to take effect from 6 April 2026.
This article will give an overview of the Construction Industry Scheme and provide a comprehensive guide to the different aspects of the scheme.
What is Construction Industry Scheme?
The Construction Industry Scheme (CIS) is a UK tax deduction and reporting regime designed to ensure proper tax and National Insurance collection from businesses operating in the construction industry.
Contractors and subcontractors need to understand the scheme and the different roles and responsibilities associated with it.
The main aim of this scheme is to ensure that tax and National Insurance Contributions (NICs) due on subcontractor income are collected correctly through deductions at source.
Who Needs to Register for the Construction Industry Scheme?
In order to avoid penalties for non-compliance and ensure that their payments and deductions are accurate, contractors working in the construction industry are required to register for the Construction Industry Scheme (CIS). Subcontractors may voluntarily choose to register, but if they do not, contractors must deduct tax at a higher rate.
Contractors
If you are a mainstream contractor or deemed contractor, you must register for CIS.
Who is Mainstream Contractor?
A mainstream contractor is the one whose core business is construction and who hires and pays another business to carry out the construction work
This includes:
- Property developers
- Speculative builders
Who is Deemed Contractor?
To be counted as a Deemed Contractor, the entity must have had an expenditure of £3m in construction operation in the past 12 months.
This includes:
- Local authorities
- Government departments
- Non-construction business
- Housing association
- Commission for the development of the new town
For Example,
ABC Ltd is a property investor that incurs £4.1 million renovating a building. Because it exceeded the £3 million threshold on construction operations, it must register as a contractor for CIS.
Subcontractors
A subcontractor is a self-employed business or limited company that a contractor engages to perform the construction work.
These includes:
- Corporations, self-employed individuals or partnerships
- Local authorities carrying out construction for others
- Labour agencies providing workforce to a contractor
- Overseas businesses undertaking construction work in the UK
Unlike contractors, the subcontractors are not forced by law to register under CIS. They can choose either to register or not for the construction industry scheme.
A Business That is Both Subcontractor & Contractor
Many businesses often undertake construction work but outsource a part of the construction job to other businesses, either as a lack of time or skilled personnel.
A business that assumes the dual roles of a contractor and subcontractor must register under CIS in both capacities. Further, they abide by the rules of the Contractor when assuming the role of Contractor and abide by the rules of the subcontractor when acting as a subcontractor.
Operations Falling Under CIS
Construction Industry Scheme (CIS) requires the Contractor to make a tax deduction when paying a subcontractor for the 'construction operations' done under a contract.
So, this leads us to ponder what operations fall within the scope of CIS as a 'Construction Operations'.
Construction Operations
- Site preparation, site restoration, earth moving, excavation, landscaping
- Constructions, alternation, extension, demolition, dismantling, repairs building structure
- Installation of heating, water supply, lighting, air conditioning system
Non-Construction Operations
- Drilling, digging for or extraction of oil, natural gas or minerals
- Soil environment testing, pipeline inspection, professional work of architects or surveyors
- Manufacture of engineering equipment, plant and machinery
Invoice Splitting
Some subcontractors may issue separate invoices for construction and non-construction operations to avoid tax deductions on the non-construction portion of the contract work.
With aim of discouraging such invoice-splitting practices, the CIS rules state that if you do multiple jobs under one contract, even if some are non‑construction, CIS deductions apply to the contract as a whole.
Alike construction jobs, the payment for non-construction jobs undertaken within the same contract is also subject to CIS tax deductions.
Contractor’s Obligation Under Construction Industry Scheme
As a contractor, you have specific obligations which you need to fulfill under the CIS.
Contractor's obligations are designed to ensure that the scheme operates effectively and that every construction business complies with relevant tax laws.
1. Confirm Subcontractor's Employment Status
The tax deductions under CIS only apply on the payment made to self-employed sub- contractors, not employees.
In cases where the subcontractors are employed, the contractor must operate workplace payroll, with taxes being deducted through Pay as You Earn (PAYE) system.
2. Verify Subcontractors
The contractor must confirm the subcontractor’s registration status with HMRC to know at what rate the CIS deduction is to be made from the subcontractors payment.
The process is called subcontractors verification. Based on the verification status, the rate of deduction may vary for each one.
3. Make CIS Deductions from Payments
Once the deduction rate is confirmed, the contractor must deduct CIS each time a payment is made to the subcontractor. CIS has to be deducted only from the labour portion of the payment.
The deduction may be at 20% or 30% or no deduction if the subcontractor has obtained gross payment status.
4. Submit Monthly CIS Returns
Every month, a contractor must submit CIS Return notifying HMRC about the payments to all subcontractors. Alternatively, where no payments have been made, the Nil CIS Returns must be sent. The return must be submitted to HMRC by the 19th of the month following the tax month in which payments were made.
5. Maintain Records
As per the CIS regulations, contractors are required to keep their records for a minimum of 3 years after the end of the tax year they belong to. Additionally, they should be able to provide these records if HMRC requests to see them. This is to ensure that contractors are compliant with the CIS rules and regulations.
Subcontractor’s Obligation Under Construction Industry Scheme
Despite the subcontractor does not have compliance requirements to the same extent as the contractor, HMRC demands the subcontractor to perform certain obligations.
These include registering for CIS (if they wish to reduce deduction rates), allowing contractors to deduct CIS, filing annual tax returns and paying any additional tax due on time.
Any non-compliance can result in penalties or fines to subcontractors.
1. Register with HMRC
The subcontractor that is not registered with HMRC, means HMRC cannot verify their records. To be on the safe side, HMRC requires a CIS deduction at a higher rate of 30% for such subcontractor.
2. Apply for Gross Payment Status
The subcontractor with Gross payment status can receive its payment in full without any tax deduction by the contractor i.e., 0% CIS Deduction.
So as to apply for the gross payment status, the subcontractor must first get registered for the Construction Industry Scheme (CIS).
3. Keep Records
The subcontractor should maintain documentation of all the deduction statements supplied by its contractor as proof of the CIS tax deduction it suffered.
Subsequently, they will need the payment & deduction statements to recover all the CIS deductions they suffered.
Repercussions of Non-Compliance with CIS Regulation
Compliance with the Construction Industry Scheme (CIS) regulations is crucial for businesses in the construction industry.
In this part, we take a look at the penalties for late CIS filing, interest charges on late payments or overpayments.
Penalties for Late CIS Filing
HMRC will levy penalties on a cumulative basis for any CIS return filed after the deadline date.
Late Payment Duration | Penalty Amount |
|---|---|
1 Day Late | £100 |
2 Months Late | £100 initial + £200 next |
6 Months Late | £300 initial or 5% if unpaid tax deduction due on the return, whichever is higher |
12 Months Late or More | £300 additional amount or 5% if unpaid tax deduction due on the return, whichever is higher |
Note: If you have not filed your CIS Return for more than 2 months, and your monthly unpaid CIS deduction is more than £6,000 then :
The 'next £300' in the above table would be substituted by 5% of unpaid CIS tax.
Interest on Late Payment & Overpayment
HMRC charges interest on late CIS payments according to the rates published at the time of payment.
In order to ensure impartiality, HMRC also compensates businesses for any sums due to them by paying interest on the repayment.
HMRC publishes current late payment and repayment interest rates, which may vary over time.
Penalties for Poor Records
It is important for contractors to keep accurate records of payments made under the CIS, not only to avoid penalties but also to ensure compliance with tax laws and regulations.
Dealing with Nil CIS Returns
CIS Inactivity Period
The CIS inactivity period is when contractors may not need to submit a monthly CIS return, provided HMRC is notified in advance.
Contractors used to be able to request an exemption from filing CIS returns with HMRC for a period of six months, provided they were confident that no payments would be made to subcontractors during that time. But the old six-month exemption is no longer available. Now, contractors must notify HMRC if no payments will be made.
Instead of submitting a monthly nil return, contractors should notify HMRC if they expect inactivity.
File Future CIS Returns
If a contractor expects no payments to subcontractors in the coming months, they should submit nil returns for each month to HMRC.
CIS returns must be submitted monthly after payments have been made, even if the payment amounts are already known.
Need a CIS returns? We handle nil return filing and keep you compliant with HMRC
Claim Back Construction Industry Scheme Deductions
It is worth noting that subcontractors are eligible to claim back all the Construction Industry Scheme (CIS) deductions that they have faced. However, the process of claiming back these deductions may vary depending on whether the subcontractor is a sole trader, in a partnership, or a limited company.
The exact steps and documentation required may differ based on the type of business entity, so it is important for subcontractors to carefully review the requirements.
Sole Trader/Partnerships
For subcontractors who operate as sole traders or partnerships, it is possible to reclaim all the CIS deductions they have suffered by including them on their self-assessment tax return. This involves providing details of the deductions made under the CIS, which will reduce the final amount of tax owed for the year.
Any outstanding tax must be paid to HMRC by 31st January following the end of the tax year.
In contrast, if there are still any unclaimed CIS deductions the subcontractor can claim repayment of any overpaid tax from HMRC.
Learn exactly where to enter your CIS deductions, how the 20% offsets your tax bill, and whether HMRC owes you a refund.
“How to Enter CIS Deductions on Your Self Assessment Return”
Limited Company
In the case of a subcontractor who operates as a limited company, any CIS deductions suffered can be claimed through the company's monthly payroll system. The company's total PAYE and NIC liability will be outlined in the Full Payment Summary (FPS), which is submitted via Real Time Information (RTI). To claim the CIS deduction suffered amount, an Employer Payment Summary (EPS) is used.
When the EPS is submitted, HMRC will offset the total tax liability as per the FPS against the CIS deduction claimed. If the subcontractor still owes HMRC after this process, any outstanding tax must be paid by the 22nd of the following month.
Whereas, if HMRC owes to the company, the subcontractor can get money back for any amount paid in excess. The CIS refund request can be made either via online or by post.
Be Careful: When claiming your CIS deductions suffered through Corporation Tax Return. HMRC strictly prohibits this and can even charge a penalty.
Frequently Asked Questions
Contractors
Subcontractors
If you are not in the construction business but you have spent more than £3m in prior 12 months. You must register for CIS.
You will continue to count as a deemed contractor if your expenditure on construction work is above £3m within 12 months period.
Contractors must submit monthly CIS returns and pay HMRC the CIS tax deducted from subcontractor payments.
The contractors should keep their records for a minimum of 3 years from the end of the tax year to which they belong.
The CIS scheme only applies to self-employed subcontractors and, not to the employed one.
If the subcontractor wishes to bypass CIS deductions at a higher rate, it must register under CIS.
If you are a self-employed sub-contractor without UTR, you can sign up for Self-assessment and CIS simultaneously.
If a subcontractor has not been paid or included in prior monthly returns for over two years, the contractor must verify their tax status to see if it has changed.
Also Learm about this “HMRC Construction Industry Scheme: CIS 340”
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