CIS deductions and refunds, allowable tools, van, PPE and home-office costs, NIC, VAT and MTD explained for self-employed worktop and kitchen fitters.
Kitchen and worktop fitting is a precise, capital-heavy trade with a tax profile that catches a lot of fitters out. You buy expensive tools, run a van full of stock, recharge materials to customers, and on most jobs you are paid by a builder or kitchen company that lops 20% off your labour before the money reaches you. Get the record-keeping right and that 20% comes back as a refund. Get it wrong and you either overpay or trip over the VAT and MTD thresholds without realising your supply-and-fit turnover crossed the line months ago.
This guide is built around how worktop fitters actually earn and spend: CIS deductions and the refund they usually produce, the specific tools and van costs that make up the bulk of your deductions, how recharged materials behave for VAT, and when MTD kicks in. If you work as a subcontractor, read it alongside our detailed CIS subcontractor guide.
As a sole trader you pay Income Tax on profit, which is your total invoiced income (labour plus any materials you recharge) minus allowable expenses. For 2025/26 the personal allowance covers the first GBP 12,570, then you pay 20% up to GBP 50,270, 40% to GBP 125,140 and 45% above, with the personal allowance tapering away between GBP 100,000 and GBP 125,140 to create an effective 60% band. Class 4 National Insurance is 6% on profit between GBP 12,570 and GBP 50,270 and 2% above, with Class 2 NIC settled through Self Assessment.
Scottish fitters pay Scottish Income Tax on profit through six bands (19%, 20%, 21%, 42%, 45% and a 48% top rate) and carry an S-prefixed tax code, while National Insurance stays UK-wide. Welsh fitters have a C-coded tax code at rates currently matching the rest of the UK. If you also have a PAYE job or your code looks off, run it through the tax code checker so a wrong code is not quietly costing you each payday.
If you fit worktops as a subcontractor for builders, kitchen retailers or main contractors, the Construction Industry Scheme almost always applies to your labour. The contractor verifies you with HMRC and deducts tax from your labour before paying you: 20% if you are CIS-registered, 30% if you are not. That deduction is an advance payment toward your eventual Income Tax and Class 4 NIC, not an extra tax.
Two points matter here. First, the deduction is taken from your labour only, not from the materials portion of an invoice, so itemise labour and materials separately on every invoice you raise to a contractor. Second, the 20% is calculated with no regard for your personal allowance or expenses. Because your first GBP 12,570 of profit is tax-free and your tools, van and insurance cut taxable profit further, the tax actually due at the end of the year is usually well below the 20% already taken. The difference comes back as a Self Assessment refund, which for a busy fitter is often a few thousand pounds.
Register as a CIS subcontractor with HMRC to get the 20% rate rather than 30%, keep every CIS payment and deduction statement the contractor gives you, and total the deductions when you file. Estimate the likely refund with the CIS tax calculator before you file so you know what to expect.
An expense is allowable when incurred wholly and exclusively for the business. Yours is a tool-heavy, van-based trade, so equipment and travel dominate the list rather than the home-office costs that drive a desk-based business.
| Expense | What qualifies | Notes |
|---|---|---|
| Power tools | Plunge and edge routers, jigsaws, circular and track saws, biscuit jointers, dust extractors | Larger tools usually claimed in full via the Annual Investment Allowance |
| Hand tools and access | Clamps, trestles, sash cramps, levels, squares, chisels, worktop jigs | Replaced regularly; deduct as bought |
| Consumables | Router bits, saw blades, biscuits, colour-fill, adhesive, silicone, sandpaper, sealant | Fully deductible running costs |
| Van and travel | Van purchase or lease, fuel, insurance, tax, servicing, repairs, or HMRC mileage at 45p/25p | Choose actual costs or simplified mileage, not both |
| PPE | Safety goggles, ear defenders, FFP dust masks, knee pads, gloves, steel-toe boots | Protective gear only; ordinary clothing is not allowable |
| Insurance | Public liability and tool insurance | Essential and fully deductible |
| Materials recharged | Worktops, edging, fixings and trims you buy and bill to the customer | Report income gross, deduct the material cost |
| Phone and admin | Business mobile, a share of broadband, quoting and invoicing software | Apportion out the private share |
| Home office | HMRC flat-rate working-from-home allowance or a fair proportion of running costs | For quotes, paperwork and ordering |
| Accountancy and bank fees | Bookkeeping, Self Assessment, business banking | Fully deductible |
Your big-ticket buys, a new router, a track saw, a dust extractor or the van itself, are capital purchases. Rather than spreading them over years, the Annual Investment Allowance lets you deduct the full cost in the year you buy, which usually gives the biggest immediate tax saving. A van bought for the business qualifies; a car does not (you use mileage or actual running costs for a car). For the van you pick one method and stick to it: simplified mileage at 45p for the first 10,000 business miles then 25p, or the actual proportion of all running costs. Mileage is simpler and often better for high-mileage fitters; actual costs can win if the van was expensive to buy or run.
The private share of dual-use broadband, phone and the van must be excluded. Ordinary clothing is never allowable even if you buy sturdy jeans or a branded polo, only genuine protective equipment counts. Travel from home to a regular base counts as commuting and is not allowable, though travel between job sites is. And fines, parking penalties and the cost of your own lunch on a job are not deductible.
If you are just starting and your gross self-employed income from all work is GBP 1,000 or less in a tax year, it is covered by the trading allowance, tax-free and with no need to register for Self Assessment. Cross GBP 1,000 and you must register and report the full amount. In practice a working fitter blows past GBP 1,000 in a week or two, so the allowance mainly matters for a first partial year or genuine sideline work. Note that if you are paid under CIS the contractor will have deducted tax regardless, so you will want to file anyway to reclaim it.
Good records are what turn the CIS deduction into a refund and keep you the right side of HMRC. The discipline is simple but easy to let slip on busy weeks:
For a CIS fitter the refund lives in your receipts. Every router bit, tube of silicone and tank of diesel you log is profit the taxman already overcharged you for and will hand back at filing.
Take a self-employed fitter working mainly for two kitchen companies under CIS, invoicing GBP 45,000 of labour over the year (materials are billed and supplied separately by the retailers, so this example is labour-led).
Labour income: GBP 45,000
CIS already deducted at 20%: GBP 9,000
Allowable expenses:
Taxable profit: GBP 45,000 minus GBP 10,100 = GBP 34,900
Income Tax: GBP 34,900 minus GBP 12,570 = GBP 22,330 at 20% = GBP 4,466
Class 4 NIC: GBP 22,330 at 6% = GBP 1,340
Total Income Tax and NIC due: GBP 5,806
Less CIS already deducted: GBP 9,000
Refund due: roughly GBP 3,194. The 20% taken at source far exceeds the GBP 5,806 actually owed once the personal allowance and expenses are applied, so HMRC repays the difference. Run your own labour, expenses and CIS figures through the sole trader tax calculator to estimate where you will land.
You must register for VAT once taxable turnover exceeds GBP 90,000 in any rolling 12-month period. A labour-only subcontractor may never approach this, but a fitter who supplies and installs worktops can get there fast because the materials you buy and recharge count toward turnover, not just your labour. Two stone or quartz supply-and-fit kitchens a month can quietly add up.
Once registered, most construction services between two VAT-registered businesses fall under the domestic reverse charge: instead of you charging and collecting VAT, your VAT-registered contractor customer accounts for it. You note on the invoice that the reverse charge applies and do not add VAT to that line. It is a common trip-up for newly registered fitters, so get it right from your first VAT invoice. Track your rolling 12-month turnover every month so a busy stretch of supply-and-fit work does not push you over the line unnoticed and leave you owing VAT you never charged.
Making Tax Digital for Income Tax Self Assessment replaces the once-a-year return with quarterly digital submissions and a year-end finalisation. The thresholds are based on gross income, not profit:
For a worktop fitter the gross-income test is the catch. If you supply and recharge materials, your turnover includes those materials, so you can cross GBP 50,000 of gross income while making a far smaller profit. Check your total invoiced figure, not your take-home. The upside is that recording each job, CIS statement and tool receipt digitally as it happens makes the quarterly summaries straightforward and your refund easier to evidence. Our guide to MTD for sole traders walks through the quarterly rhythm in practice.
Not registering for CIS. Staying unregistered means 30% deducted instead of 20%, tying up more of your cash until you file.
Letting CIS slip and not deducting from labour only. Materials, plant and VAT are excluded from the CIS calculation, so contractors should only deduct from labour. Itemise invoices so they do.
Losing tool and fuel receipts. Every unrecorded receipt is expense you cannot claim, which directly shrinks your refund.
Ignoring the VAT threshold on supply-and-fit jobs. Recharged materials count toward the GBP 90,000 line; track rolling turnover so a busy run does not tip you over unnoticed.
Assuming the gross-income MTD test is about profit. It is your total invoiced turnover that counts, materials included, so check the right number.
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