Navigating the UK Construction Industry Scheme (CIS)
The Construction Industry Scheme (CIS) is a set of tax and National Insurance rules specifically designed for individuals and businesses operating in the UK construction sector. Whether you are a contractor or subcontractor, understanding how the scheme works is essential for staying compliant and managing your CIS tax obligations correctly.
Many businesses also seek support from CIS accountants to ensure compliance is handled accurately and efficiently, particularly where deductions, reporting, and refunds are involved.
What is the Construction Industry Scheme (CIS)?
The CIS is a UK government tax framework that requires contractors to deduct a percentage from payments made to subcontractors and pass this directly to HMRC. These deductions act as advance payments towards the subcontractor’s income tax and National Insurance liabilities.
For many subcontractors, understanding how CIS tax is calculated and deducted is crucial to avoiding errors and ensuring they do not overpay.
These changes make it even more important for businesses to stay compliant with CIS tax rules and maintain accurate records with support from qualified professionals.
Who Does the Construction Industry Scheme Apply to?
The CIS applies to contractors who pay subcontractors for construction work or businesses that have spent more than £3 million on construction in the 12 months since their first payment. While subcontractors are not obligated to register for the CIS, they will see a 30% deduction from their payments if they remain unregistered. However, if a subcontractor registers under the CIS, this deduction is reduced to 20%. Alternatively, subcontractors can apply for gross payment status.
From 6 April 2026, HMRC will be able to act immediately where a business makes or receives a payment that it knew, or ought to have known, was connected to fraud. In these cases, HMRC will have the authority to withdraw Gross Payment Status (GPS) immediately, assess the business for any related tax losses, and impose penalties of up to 30%. Penalties may apply to the business itself or, in some circumstances, to its officers. Where GPS status is removed due to fraud or serious non-compliance, the business will also be prevented from reapplying for five years, a significant increase from the current one-year restriction.
In addition, contractors must also ensure ongoing compliance with CIS monthly returns, as failure to submit accurate or timely returns can lead to penalties and increased scrutiny from HMRC.
What are the Reporting Obligations under C.I.S.?
Under the CIS, contractors are required to submit CIS monthly returns online, which detail payments made to subcontractors for each tax month (from the 6th of one month to the 5th of the next). The deadline for submission is 14 days after the end of the tax month. If a contractor doesn’t make any payments to subcontractors in a particular month, they must submit a ‘CIS nil return’ or notify HMRC that no return is due.
Changes in VAT Rules under the c.i.s.
As of 1 March 2021, the VAT rules for building contractors and subcontractors have changed. For certain specified supplies, subcontractors no longer add VAT to their services for most building customers. Instead, contractors are required to pay the output VAT on behalf of their registered subcontractor suppliers – a mechanism known as the Domestic Reverse Charge. Contractors can then reclaim the output tax paid as input VAT, as per the standard rules.
Need Assistance from an Accountant?
Navigating the Construction Industry Scheme can be complex, particularly when dealing with monthly CIS returns, subcontractor deductions, and HMRC deadlines. Working with experienced CIS accountants in London can help contractors and subcontractors remain compliant and avoid costly penalties. At CIGMA Accounting, we provide specialist CIS and tax compliance support for construction companies, while also advising retailers, healthcare professionals, and recruitment companies operating across the UK.
Our team of tax accountants in London supports businesses through our local offices in Hammersmith and Fulham Broadway, as well as surrounding areas including Goldhawk Road, Shepherd’s Bush, Munster Village, and Bishop’s Park. Clients are welcome to visit our offices across London to discuss CIS compliance, ongoing tax obligations, and practical solutions tailored to their business needs.
For official guidance on CIS rules, deductions, and contractor responsibilities, you can refer to HMRC’s Construction Industry Scheme guidance on GOV.UK.
If you’re looking for reliable CIS accountants near you, our team can assist with CIS registration, monthly and nil returns, and HMRC correspondence.
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