Navigating the Construction Industry Scheme (CIS) can be daunting, especially when it comes to reclaiming overpaid tax. Whether you’re a self-employed subcontractor or a director of a limited company, understanding how to claim a CIS refund can save you hundreds, sometimes thousands, of pounds each year.
In this guide, we’ll walk you through the entire process of how to claim CIS tax back, from the documents you’ll need to the methods available for claiming, either online, by post, or through a tax specialist like Swift Refunds.
What Is a CIS Tax Refund?
Under the Construction Industry Scheme, contractors deduct tax at source from subcontractors’ payments, typically 20% if you’re registered with HMRC. However, these deductions don’t account for all your work-related expenses, which means many subcontractors overpay tax throughout the year.
That’s where a CIS refund comes in. By submitting a self-assessment return or company tax return (for limited companies), you can reclaim what you’re owed.
What You Need to Claim a CIS Refund
Before you begin, make sure you have all the right documentation. Missing or incorrect information is one of the most common reasons claims are delayed or rejected by HMRC.
You’ll need:
- • CIS payment and deduction statements from your contractors
- • Invoices issued to your contractors
- • Your Unique Taxpayer Reference (UTR)
- • Government Gateway login details
- • Your bank account details for the refund
- • Records of allowable expenses (e.g. tools, travel, mileage, PPE)
How to Claim CIS Refund Online (For Self-Employed Subcontractors)
If you’re self-employed and registered under CIS, you’ll claim your refund by submitting a Self Assessment tax return.
Step-by-step:
- 1. Log in to your HMRC Government Gateway account
- 2. Select “Complete your tax return”
- 3. Fill in your total income, CIS deductions, and allowable expenses
- 4. Submit your return by the 31st January deadline for the previous tax year
- 5. HMRC will calculate your tax liability and issue a refund (usually within 2–8 weeks)
Tip: Always double-check CIS deductions against your payment statements, HMRC will compare these totals.
How to Claim CIS Refund Online (Limited Companies)
If you’re claiming a CIS tax refund online as a limited company, you’ll need to do so through your PAYE system. So, each month you will need to submit a Full Payment Submission (FPS) and an Employer Payment Summary (EPS) to HMRC, reporting any CIS deductions there.
The deductions you submit are offset against your limited company’s PAYE and National Insurance liabilities, and if they exceed these liabilities, you’re eligible to request a refund at the end of the tax year.
How to Claim Your CIS Tax Back by Post
Prefer the paper route? You can submit your Self Assessment tax return or form R38 form by post, but be aware that it’s significantly slower.
Postal claims must be sent by:
- • 31st October, following the end of the tax year (for paper Self Assessment returns)
- • Include all supporting documents (statements, invoices, expense records)
Claiming Through an Accountant Like Swift Refunds
Let’s face it, filing your own tax return can be time-consuming, confusing, and stressful. That’s why thousands of subcontractors and limited companies choose to claim their CIS refund with Swift Refunds.
Why use Swift Refunds?
- • We offer a fast, online process – check eligibility and upload documents in minutes
- • We’re HMRC-compliant – we ensure your claim meets all the rules and regulations
- • Swift Guarantee – we cover the cost if HMRC requests repayment (provided the inforomation you gave is correct)
We specialise in tax rebates for many different industries, including construction workers, and anyone working under CIS, so you know you’re in safe hands.
Common Mistakes To Avoid When Claiming a CIS Refund
Avoid delays and rejections from HMRC by steering clear of these common errors:
- • Incomplete or missing CIS deduction statements
- • Totals that don’t match what HMRC has on file
- • Forgetting to include valid business expenses
- • Using the wrong tax year
- • Submitting your return late
How to Follow Up With HMRC About Your Refund
If you’ve submitted your claim and want to track progress, HMRC offers a few ways to follow up:
- • Use the online refund tracker in your Government Gateway account
- • Call HMRC’s Self Assessment helpline (0300 200 3310)
- • If it’s been over 6 weeks, consider resubmitting or escalating your claim
Need Help Claiming Your CIS Refund?
At Swift Refunds, you won’t need to wonder ‘how do I claim my CIS refund?’ anymore, we make the process effortless, you will hardly need to lift a finger. Whether you’re a self-employed tradesperson or managing a limited company, we’ll ensure you get the maximum refund possible, without the hassle. When you choose to claim a CIS refund with us, we can guarantee:
- • Quick claims
- • A transparent process
- • A quality service trusted by many across the UK construction industry
Ready to get started? Claim your CIS refund today with Swift Refunds.


