Voice and visuals made with automated software, including AI.
Yes. A CIS refund is part of your own Self Assessment tax return, which you can file yourself. For the 2026-27 tax year you can file from 6 April 2027, and HMRC repays any excess deductions.
Under the Construction Industry Scheme (CIS), the 20% your contractors take is an advance payment towards your tax and National Insurance. GOV.UK tells sole traders to record their total pay before deductions as income and the total deductions as CIS deductions on their tax return. HMRC then works out what you owe, takes off the deductions, and pays back anything left over. There is no separate refund form for a sole trader who is still trading, and no rule that an agent has to do it.
Want your books sorted?
We sort your books and prepare your quarterly figures. You send them to HMRC yourself with free Making Tax Digital software.
Founding offer on Trades Tax (coming later), first 500 trades clients: £5 a month for your first 3 months, then £35 a month. Cancel any time. We’ll remind you before it changes. Prices include VAT. No payment is taken while you wait.
Are you ready for Making Tax Digital? Check your start date and what to sort first. It’s free and takes a minute.
What filing it yourself involves
The work is mostly gathering paper. Once your figures are in order, the return itself is a set of boxes.
| What you need | Where it comes from |
|---|---|
| Your Unique Taxpayer Reference (UTR) | Letters from HMRC, your personal tax account or the HMRC app |
| HMRC sign-in details | Created online when you first sign in |
| Every monthly payment and deduction statement, 6 April to 5 April | Your contractors, within 14 days of the end of each tax month |
| Total business costs, with receipts | Your own records: materials you bought, van, tools, phone |
| Your UK bank account details | So HMRC can pay the refund into your account |
On the 2025-26 paper forms, CIS deductions go in box 38 of the short self-employment pages (SA103S) or box 81 of the full pages (SA103F). Your pay before deductions goes in as turnover. Online, the same questions appear in the self-employment section.
What this means for you
If you worked under CIS all year, kept your statements and know what you spent, you can claim the refund yourself. HMRC does the tax calculation once you enter the figures, so you are not doing sums by hand.
What you do need to get right is the numbers you put in. Two mistakes cost subcontractors money. The first is leaving out costs, which means paying tax on profit you never made. The second is entering pay after deductions as turnover, which understates your income while still claiming the deductions, and is the sort of mismatch HMRC queries. HMRC compares the deductions you claim with the monthly returns your contractors send it.
From 6 April 2027, if your income from self-employment and property before costs was over £30,000 in 2025-26, you join Making Tax Digital for Income Tax (MTD). You then keep digital records, send quarterly updates and file your tax return from MTD software. GOV.UK says HMRC adds your CIS deductions to your MTD tax return for you to check, and you request any refund through your HMRC online services account. Your 2026-27 return is still an ordinary Self Assessment return.
Steps to claim it yourself
- Find your UTR and make sure you can sign in to HMRC online services.
- Collect every monthly payment and deduction statement for the tax year. Ask any contractor who has not sent one.
- Add up the gross pay and the deductions on the statements, and check each payment against your bank account.
- Total your business costs for the year and keep the receipts.
- After 5 April, complete your tax return. Enter gross pay as turnover, your costs as expenses, and total deductions as CIS deductions.
- Add your UK bank details so HMRC can pay the refund there, then submit.
- Keep your statements. HMRC may ask for evidence of your deductions.
When paying for help is worth it
Doing it yourself suits one year of straightforward CIS work. Help is more likely to pay for itself when:
- you have two or more years of returns to catch up, with penalties to sort out
- HMRC has written to query your deductions or your costs
- you bought a van or expensive equipment, and capital allowances come into it
- you also had a job, rental income or a partnership
- you are VAT-registered, or your contractors are applying the VAT reverse charge
- you have lost statements from a contractor that has gone out of business
Be wary of anyone who takes a percentage of your refund without telling you what it is, or who promises a refund by a set date. HMRC asks people to allow up to 4 weeks after a return before chasing a repayment, and security checks can make it longer.
Where we fit
Our service is for subcontractors who want the books kept and the returns filed from their records, with CIS deductions counted in the tax return, and you confirming every figure first. It is not open yet. Our tax plans start once our HMRC registrations are complete. Until then you can join the waitlist, and no payment is taken.
Use the free MTD check to see whether Making Tax Digital applies to you from April 2027, and visit the trades section for more on CIS.
Hold your place on the trades waitlist
We’ll email you when Trades Tax opens, with the founding offer while places last. No payment is taken.
Questions people ask
Do I have to use an accountant to get my CIS money back?
No. A sole trader's CIS refund is claimed on their own Self Assessment tax return. You can file that return yourself online. HMRC works out the tax you owe, takes off your CIS deductions and repays any excess.
What do I need before I start my tax return?
Your UTR, your HMRC sign-in details, every monthly payment and deduction statement for the tax year, a total of your business costs with receipts, and your UK bank details so HMRC can pay the refund.
Is it worth paying someone to claim my CIS refund?
It can be if you have several years to catch up, a letter from HMRC querying your figures, a van or equipment to claim, or other income to fit in. For one year of simple CIS work, you can usually file it yourself.
Where do the CIS figures go on the tax return?
On the self-employment pages. Your pay before deductions is your turnover and the total deducted goes in the CIS deductions box: box 38 of the short pages (SA103S) or box 81 of the full pages (SA103F) on the 2025-26 forms.
Can a refund company get my money back faster?
No one can make HMRC pay sooner than it processes your return. Over-deducted CIS is claimed back through your tax return. The sooner after 5 April you file, the sooner HMRC can repay you.
Sources
- What you must do as a CIS subcontractor: Pay tax and claim back deductions (GOV.UK)
- What you must do as a CIS subcontractor: Get paid (GOV.UK)
- Self Assessment tax returns: Sending a return (GOV.UK)
- Find your Unique Taxpayer Reference (UTR) (GOV.UK)
- Use Making Tax Digital for Income Tax: Submit your tax return (GOV.UK)
- CISR75020: SA subcontractors, claims for credit in SA returns (HMRC manual)
- Construction Industry Scheme: a guide for contractors and subcontractors, CIS 340 (GOV.UK)
This is general information to help you understand the rules. It isn't tailored to your circumstances, so check your own position before acting on it.
Righto Tax is a trading name of NJG Consultancy Ltd, registered in England and Wales, company number 16095900. Registered office: Jubilee House, East Beach, Lytham St Annes, FY8 5FT.
All CIS guides for subcontractors
What happens next
- Use the free Making Tax Digital checker to see your own start date and deadlines.
- See what Righto Tax for Trades does for you, and join the waitlist.
- Questions about this page? Email hello@rightotax.co.uk.