Checklist
CIS tax return checklist for subcontractors, 2025–26.
What to ask construction subcontractors for, from every contractor's monthly statements to tools, van costs and mileage, with "why we ask" lines and a plain-words version.
Last updated · Facts checked
Under the Construction Industry Scheme (CIS), contractors take 20% from a registered subcontractor's pay for labour and send it to HMRC, or 30% if the subcontractor isn't registered. Those deductions are advance payments towards the subcontractor's tax and National Insurance, taken before their costs or personal allowance count. That's why a CIS subcontractor's Self Assessment return often ends in a refund, and why a missing statement or receipt can cost them money.
This CIS tax return checklist covers the 2025–26 tax year, 6 April 2025 to 5 April 2026. The online return, and any tax still owed, are due by 31 January 2027.
Before you send it
These are typical items to tailor to each client, not a list of what HMRC requires. Start from last year's return, then:
- Count the statements. A contractor gives one for each tax month in which they paid your client, and a tax month runs from the 6th to the 5th. Six months with one contractor means six statements.
- Ask for the contractor names first. A list of everyone your client worked for is the only way to know when a statement is missing.
- Keep the "why we ask" lines. Clients find the right paper faster when they know what it's for.
The list is for sole traders, who report CIS on the self-employment pages of their return. A limited company claims its deductions differently (see the FAQ), so for a company use the year-end accounts checklist for a limited company.
The CIS tax return checklist
CIS statements and your details
| Document | Why we ask |
|---|---|
| Every monthly CIS payment and deduction statement, from every contractor you worked for | They show what you were paid and the tax already taken. The deductions go on the return as tax you've paid. |
| A list of the contractors you worked for in the year | So we can check there's a statement from each of them, for every month they paid you. |
| Your Unique Taxpayer Reference (UTR) | We need it to file your return. It's on letters from HMRC. |
If a statement is missing. GOV.UK says the contractor must give it within 14 days of the end of each tax month. Ask the contractor for a copy: HMRC's CIS340 guide says a duplicate must be marked "Duplicate". If the contractor has gone out of business, see the first question in the FAQ below.
Income
| Document | Why we ask |
|---|---|
| Invoices you issued, for CIS work and any other jobs | The return needs your full pay before deductions, and any work with no statement. |
| Bank statements for every account your work is paid into | To match payments to statements and invoices, and to find costs you've forgotten. |
Costs
| Document | Why we ask |
|---|---|
| Receipts for materials you paid for, including cash purchases | Materials are a business cost, and no CIS deduction should be taken on them. |
| Receipts for tools and protective clothing, such as safety boots and hard hats | Both can be claimed. Everyday clothing can't, even if you wear it on site. |
| Van or vehicle costs: fuel, insurance, repairs, finance, or the invoice for a van bought this year | We can claim the business share of running it, and allowances for buying it. |
| Mileage log of business journeys | We can claim a flat rate per business mile instead of running costs, but not both for the same vehicle. |
| Mobile or phone bills | The business share can be claimed. |
| Course, test and card fees, such as a CSCS card | Training that keeps up the skills you use for your work can be claimed. We'll check which fees qualify. |
| Parking, tolls, fares and overnight stays when working away | Travel to and between temporary sites is usually a business cost. |
Other income
| Document | Why we ask |
|---|---|
| P60 or P45 from any job you had in the year (if any) | Pay from a job goes on the return too, separately from your CIS work. |
Set your due date in November
Ask for everything by the end of November. Missing statements take time to get from contractors, and December leaves room to chase them and prepare the return.
What usually goes missing
- Statements from short jobs. A contractor your client worked for for two weeks in July is easy to forget, and so is their one statement.
- Months in the middle of a run. Eleven statements from a contractor who paid every month means one is missing. Counting them is the only way to tell.
- Cash materials. Fixings and timber bought at the merchant's counter rarely make it into a folder. Bank and card statements help find the card purchases.
- Mileage. Few subcontractors keep a log. A diary, invoices with site addresses or a phone's location history can rebuild one.
- Tools on a personal card. Online orders and personal card purchases need the order email or statement as the receipt.
- Work with no statement. Private jobs paid straight into the bank don't come with a statement, so the invoices matter.
Copy the CIS tax return checklist
CIS TAX RETURN 2025–26: DOCUMENT CHECKLIST
Tax year: 6 April 2025 to 5 April 2026
CIS STATEMENTS AND YOUR DETAILS
- Every monthly CIS payment and deduction statement, from every
contractor you worked for
Why we ask: they show your pay and the tax already taken.
- A list of the contractors you worked for in the year
Why we ask: to check there's a statement from each of them.
- Your Unique Taxpayer Reference (UTR)
Why we ask: we need it to file your return.
INCOME
- Invoices you issued, for CIS work and any other jobs
Why we ask: the return needs your full pay before deductions.
- Bank statements for every account your work is paid into
Why we ask: to match payments and find forgotten costs.
COSTS
- Receipts for materials, including cash purchases
Why we ask: materials are a business cost.
- Receipts for tools and protective clothing
Why we ask: both can be claimed.
- Van or vehicle costs, or the invoice for a van bought this year
Why we ask: we can claim the business share.
- Mileage log of business journeys
Why we ask: we may claim a flat rate per business mile.
- Mobile or phone bills
Why we ask: the business share can be claimed.
- Course, test and card fees, such as a CSCS card
Why we ask: training for your work can usually be claimed.
- Parking, tolls, fares and overnight stays when working away
Why we ask: travel to sites is usually a business cost.
OTHER INCOME
- P60 or P45 from any job you had in the year (if any)
Why we ask: pay from a job goes on the return too.
Client-friendly version
Many subcontractors have never heard the words "payment and deduction statement". This version asks in plain words, so a client can work through it on site, on a phone. Paste it into your request message and remove what doesn't apply.
Your 2025–26 tax return: what we need from you
This covers 6 April 2025 to 5 April 2026. The tax taken off your
pay may be more than you owe, so the more you send, the more we
can claim back for you.
Who did you work for?
Send us the name of every contractor, even for a one-off job.
The monthly slips from each contractor
Each contractor should give you a slip for every month they paid
you, showing your pay and the tax they took off. Send them all.
If one is missing, ask the contractor for a copy.
Your tax reference
The 10-digit number on letters from HMRC (your UTR).
What you charged
Your invoices, and statements for the account you're paid into.
What you spent
Receipts for materials, tools, boots, hard hats and work gear.
Van costs: fuel, insurance, repairs, or a note of business miles.
Phone bills. Course and card fees, like your CSCS card.
Parking, tolls and hotels when working away.
Did you also have a job on a payslip?
Send your P60, or your P45 if you left.
Please send everything by [due date]. If you're not sure whether
something counts, send it anyway, or ask us.
Sending it
- One request, the whole list. Send everything at once with your due date, and one place to upload it.
- Chase the missing months by name. "We have April to August from [contractor], please send September" gets a quicker reply than "anything else?".
- Call when email stops working. A client on site all day may answer the phone sooner than an email.
For the first email, see the document request email templates. For a client with other income too, the Self Assessment checklist has the full list.
How to do this in GarnerDocs
GarnerDocs sends the checklist, collects the files and chases what's missing. It doesn't file the return or connect to HMRC.
- The checklist, ready to edit. New workspaces include a CIS Subcontractor Tax Return template with the items on this page, in four categories. Remove what doesn't apply to each client.
- Short answers where a file makes no sense. Your client types their UTR and the list of contractors instead of uploading them.
- No account, from a phone. Your client photographs paper statements and receipts and uploads a few at a time. Their progress is saved.
- Reminders that list only what's missing. They stop once everything is in. Add a one-off reminder with your own note to ask for a missing month.
- Review as files arrive. Approve each file, or ask for a replacement with a note your client sees next to that item.
Send this checklist to your client and track the uploads with GarnerDocs.
See Create a template.
Sources
- What you must do as a CIS subcontractor, GOV.UK: deduction rates, statements, claiming deductions and gross payment status. Checked on 28 October 2026.
- Construction Industry Scheme: a guide for contractors and subcontractors (CIS340), HMRC. Checked on 28 October 2026.
- Self-employment (short) notes (SA103S) for 2025–26, HMRC: turnover before CIS deductions, and the CIS deductions box. Checked on 28 October 2026.
- Expenses if you're self-employed: clothing, travel, office and phone and training, GOV.UK. Checked on 28 October 2026.
- Simplified expenses: vehicles, GOV.UK: 45p a mile for the first 10,000 business miles before 6 April 2026, then 25p. Checked on 28 October 2026.
- BIM37620: travel costs to and between sites, HMRC Business Income Manual. Checked on 28 October 2026.
- Self Assessment tax returns: deadlines and how long to keep your records, GOV.UK. Checked on 28 October 2026.
This guide is general information, not legal or tax advice. What each subcontractor can claim depends on their circumstances, so tailor the list rather than treating it as complete.
Questions
What if a contractor won't or can't give a statement?
Ask the contractor for a copy first; a duplicate is marked "Duplicate". If you still can't get it, for example because the contractor has gone out of business, GOV.UK says to write to HMRC (PT Operations, HM Revenue and Customs, BX9 1BX) with the subcontractor's name, address and UTR, the contractor's name, address and tax reference if known, the dates or tax months of the payments, and why the statements are missing.
What about a subcontractor with gross payment status?
Contractors pay them in full, with no deductions, so there's nothing to claim back. Their payments still go on the Self Assessment return as income, and the tax is paid by 31 January. Ask for the rest of the checklist as usual: invoices, bank statements and costs.
Does this checklist work for a limited company subcontractor?
Not for its CIS deductions. A limited company claims them through its payroll, by entering them on the Employer Payment Summary, not on a Self Assessment or Corporation Tax return. For the company's year-end records, use the limited company section of the year-end accounts checklist.
How long should a subcontractor keep their records?
At least 5 years after the 31 January deadline for the tax year. For 2025–26, filed online by 31 January 2027, that means until at least the end of January 2032. Keep the monthly statements too, as HMRC can ask for evidence of the deductions.