Tax, CIS and Making Tax Digital for self-employed carpenters and joiners

When Making Tax Digital starts for carpenters and joiners

It depends on your qualifying income, not your trade. Qualifying income is the total of self-employment and property income before expenses (turnover), not profit.

Once you’re in, you send HMRC a quarterly update by 7 August, 7 November, 7 February and 7 May, then a tax return after the year ends. MTD for Income Tax does not change how tax is paid or the payment due dates.

Check your own start date and what to sort first. It’s free and takes a minute.

CIS for carpenters and joiners

CIS covers carpentry done as part of a building, from first and second fix to fitted kitchens, doors and windows. Making components off site and delivering them is outside the scheme, but a contract to make and fit brings every payment under it into CIS. When you are paid under CIS, the timber you bought and what you paid to make units off site (not your own time) come off before the deduction is worked out. Fixed seating, blinds and shutters are excluded by law. Homeowners paying for work on their own home are not contractors, so they don’t deduct CIS.

When CIS applies, a contractor deducts 20% if you’re registered for CIS, 30% if you’re not, and nothing if you have gross payment status. To work out a CIS deduction, the contractor starts with the gross invoice and takes away what the subcontractor paid for VAT, consumable stores, fuel (except for travelling), plant hire, manufacturing or prefabricating materials, and materials; the CIS rate is then deducted from the amount left.

Before you join Making Tax Digital, over-deducted CIS is claimed back through your Self Assessment tax return. Once you are in Making Tax Digital, HMRC adds your CIS deductions to your tax return, and any refund is requested separately through HMRC online services. Either way, the sooner after 5 April the return is filed, the sooner HMRC can repay you.

Estimate your CIS refund

Free, and it runs in your browser: add your van or mileage, tools and phone, for 2025-26 and 2026-27.

Costs carpenters and joiners usually claim

The test for every cost is whether it was for your business. If something is partly personal, only the business part counts.

Your van, tools and kit

Where you are based decides your travel. A site carpenter who goes from home to a run of temporary sites can usually claim that travel. A joiner with a workshop cannot claim the drive between home and the workshop, because that is travel to a fixed place of work, but can claim trips from the workshop to customers and sites. Machinery and hand tools you keep are business equipment, and so is the van. If you make units off site for a CIS job, keep the timber receipts and a record of what the making cost, so both can be shown separately on your invoice.

From 2024-25 the cash basis is the default for sole traders and partnerships without corporate partners, with no turnover limit; traditional (accruals) accounting is an opt-out. Under the cash basis, the cost of equipment bought to keep and use in the business, such as machinery, computers and vans, is claimed as a normal allowable expense rather than a capital allowance. Cars are different: they go through capital allowances.

Simplified expenses for cars and goods vehicles (vans) from 6 April 2026: 55p a mile for the first 10,000 business miles, then 25p; motorcycles 24p. Once used for a vehicle you must keep using it for that vehicle, and it cannot be used for a vehicle already claimed through capital allowances.