Kitchen Fitter
Tax & MTD Guide

The tax position of a self-employed kitchen fitter is shaped by two things most office-based trades never deal with: the Construction Industry Scheme taking a slice of your labour before you ever see it, and a constant churn of tools, materials and van costs flowing through the business. Get those two things right and the rest of Self Assessment is straightforward. Get them wrong and you either overpay for years or hand HMRC an interest-free loan you never reclaim.

This guide is built around how kitchen fitters actually work: a mix of CIS subcontract jobs for builders and direct supply-and-fit work for homeowners, heavy spend on power tools and consumables, a van that is central to the business, and material costs you often buy and re-bill. Track it properly as you go and the annual return becomes a tidy-up rather than a panic.

How Tax Works for a Self-Employed Kitchen Fitter

As a sole trader you pay Income Tax on profit, which is your total fitting income minus allowable expenses. For 2026/27 the personal allowance covers the first £12,570, then you pay 20% to £50,270, 40% to £125,140 and 45% above, with the personal allowance tapering away between £100,000 and £125,140 to create an effective 60% band. Class 4 National Insurance is 6% on profit between £12,570 and £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 your code looks wrong, perhaps because CIS deductions or a part-time PAYE job are distorting it, run it through the tax code checker.

CIS: The Single Biggest Thing to Get Right

If any of your kitchen fitting is done as a subcontractor for a building contractor, property developer or main contractor, it falls within the Construction Industry Scheme. Under CIS the contractor must verify you with HMRC and deduct tax from the labour element of your invoice before paying you. The deduction is 20% if you are CIS-registered and 30% if you are not, which is the single best reason to register the moment you start subcontracting.

Two points trip fitters up. First, the deduction only applies to labour, so split your invoices clearly into labour and materials, because the contractor should only deduct from the labour line. If you lump everything together, you risk having tax deducted from your material costs too. Second, work done directly for a private homeowner is outside CIS entirely, so no deduction is made on that income and you account for the whole amount yourself.

Because CIS skims 20% off your labour before your personal allowance, tools, van and material costs are taken into account, it almost always over-collects. When you file, the £12,570 tax-free band and your real expenses reduce your actual liability, and the CIS already paid is set against it. For most fitters the result is a refund. Our full CIS subcontractor guide walks through registration, statements and reclaiming, and the CIS tax calculator shows roughly what you are owed.

Allowable Expenses for Kitchen Fitters

An expense is allowable when incurred wholly and exclusively for the business. For a kitchen fitter the list is dominated by tools, the van and materials rather than office costs.

Van Costs in Detail

The van is usually a fitter's largest running cost, and you choose one of two methods per vehicle. The simplified flat rate lets you claim a set amount per business mile with no need to total receipts, which suits a newer van with low repair costs. The actual-cost method claims a business proportion of every running cost (fuel, insurance, tax, servicing, repairs and tyres) plus capital allowances on the van itself, which usually wins for an older, higher-mileage van that needs work. Do the sum both ways once, keep a simple mileage log either way, and stick with your chosen method for that vehicle.

Materials You Buy and Re-Bill

Where you supply units and worktops as well as fitting them, the material cost is a deductible expense and the amount you charge the customer for those materials is income. Record both. Netting them off, or only logging the fitting fee, understates your turnover, which matters for the VAT and MTD thresholds that are tested on gross income. Keep supplier invoices for every kitchen you buy in.

What You Cannot Claim

The private share of the van, phone and broadband must be excluded. Everyday clothing is never allowable even though you wear it on site; only protective and branded workwear qualifies. Meals on a normal working day are not deductible, and fines or parking penalties are never allowable. Tools bought before your trade started are pre-trading expenditure, claimed once you begin trading rather than ignored.

Worked Example: A Kitchen Fitter on £46,000

Take a fitter doing a mix of CIS subcontract work for two builders and direct supply-and-fit jobs for homeowners, with £46,000 of income for the year, of which £28,000 was CIS labour that had 20% (£5,600) deducted at source.

Income: £46,000 (CIS labour £28,000, direct supply-and-fit £18,000)

Allowable expenses:

• Power tools and tool box (AIA, claimed in full): £2,200
• Consumables, blades and fixings: £1,100
• Van actual-cost proportion plus capital allowance: £4,800
• Materials re-billed on supply-and-fit jobs: £3,400
• PPE, work trousers and tool insurance: £700
• Public liability insurance: £350
• Skip hire, parking and waste charges: £600
• Phone, admin and accountancy: £850
• Total expenses: £14,000

Taxable profit: £46,000 minus £14,000 = £32,000

Income Tax: £32,000 minus £12,570 = £19,430 at 20% = £3,886

Class 4 NIC: £19,430 at 6% = £1,166

Total tax and NIC: £5,052. But £5,600 was already deducted under CIS, so this fitter is owed a refund of around £548, before any Class 2 NIC. Because CIS took 20% of labour before expenses and the personal allowance, the deductions exceeded the real bill. Run your own figures through the sole trader tax calculator to see where you land.

VAT and the Domestic Reverse Charge

You must register for VAT once taxable turnover exceeds £90,000 in any rolling 12-month period. Fitters who supply and install whole kitchens can reach this faster than they expect, because the value of the units and worktops you buy in and re-bill counts towards turnover, not just your labour. Keep a running 12-month total so registration does not catch you out.

Once VAT-registered, a second rule kicks in for construction work. The VAT domestic reverse charge applies when you do CIS construction work for another VAT-registered business that is not the end user. Instead of charging VAT and collecting it, you state on the invoice that the reverse charge applies, the contractor accounts for the VAT, and you receive only the net amount. You still reclaim VAT on your own tools, materials and van costs, which for a labour-and-materials trade often results in a VAT repayment. The reverse charge does not apply to work for private homeowners, where you charge VAT normally.

Record-Keeping and National Insurance

Keep digital or paper records of every invoice you raise, every supplier and tool receipt, your CIS payment and deduction statements, your mileage log, and your bank statements. The CIS statements are the documents that unlock your refund, so file them as they arrive rather than hunting for them in January. National Insurance comes in two parts: Class 4 at 6% then 2% on profit, calculated automatically, and Class 2, which is settled through your Self Assessment return and protects your State Pension and benefit entitlement. Even in a year where CIS deductions wipe out your Income Tax, paying Class 2 keeps your contribution record intact.

MTD for Income Tax: What Changes for Fitters

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:

• April 2026: Combined trading and property income over £50,000
• April 2027: Over £30,000
• April 2028: Over £20,000

For a supply-and-fit kitchen fitter the key trap is that the threshold is tested on gross turnover, which includes the materials you re-bill, so a fitter whose profit is modest can still be pulled in early by high material throughput. Instead of bundling a shoebox of receipts together each January, you record each invoice, tool purchase and CIS statement digitally as it happens and send HMRC a summary every quarter using MTD-compatible software. The upside is that the messy mix of CIS jobs and direct work becomes far easier to manage when it is captured continuously. Our guide to MTD for sole traders explains the quarterly rhythm.

Common Mistakes Kitchen Fitters Make

Not registering for CIS. Failing to register means contractors deduct 30% instead of 20%, tying up even more of your cash until you file.

Not splitting labour and materials on invoices. CIS should only be deducted from labour. Lump everything together and you risk tax being taken from your material costs too.

Losing CIS statements. Those statements are the proof of tax already paid. Without them you cannot easily claim your refund, so file them month by month.

Netting off re-billed materials. Report the materials you charge customers as income and the cost as an expense. Hiding them understates turnover and distorts your VAT and MTD position.

Mixing the van methods. You cannot switch between simplified mileage and actual costs for the same van mid-life. Choose once and keep a mileage log either way.

People also ask

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