What can a self-employed joiner or carpenter claim?
The oak for a staircase, the unit you make it in, the planer-thicknesser and the extraction, saw blades and sharpening, the first-fix kit and the van all come off your profit before tax. Here is how a rented workshop and a workshop at home are claimed, where the CIS line falls between fitting on site and making off site, and a worked year that mixes homeowner commissions with work for a builder.
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What a self-employed joiner can claim
Timber, sheet material and ironmongery
Sawn and planed hardwood, softwood carcassing, MDF, birch ply and MR board, veneers and lippings, hinges, locks and handles, drawer runners, sash cord and weights, glue, oil, lacquer and wax: everything that leaves with the finished piece or is fixed into the customer's building goes under Goods for resale, which HMRC heads goods used. What you bill the customer for it, mark-up or none, is turnover, and the timber yard's invoice is the cost set against it. A stock of oak bought in March for a staircase you will not start until May is still an expense of the year you paid for it under the cash basis, and the offcuts in the rack need no adjustment at the year end.
A rented unit
Rent on an industrial unit, a barn or a lock-up you machine timber in is Rent. Business rates on it are Business rates and council tax, though in England a unit with a rateable value of £12,000 or less pays nothing once small business rate relief is claimed from the council, provided it is your only business property, and the relief shrinks to nothing at £15,000. The three-phase supply that feeds the machines, water and heating are Utilities. Cover for the machinery and stock, and public liability, are Insurance. Fitting out the unit with benches, racking and a spray booth is equipment, below; building or extending the unit itself is a cost of premises, which the cash basis never deducts.
A workshop at home
If the bench is in your garage or a building at the end of the garden, claim for the home in one of two ways. HMRC's flat rate for working from home is £10 a month when you put in 25 to 50 hours there, £18 for 51 to 100 and £26 for 101 or more, with nothing to apportion. Or work out a proportion of the real costs, heating, electricity, Council Tax, mortgage interest or rent, divided by the rooms you use or the hours you use them, which for a workshop running a dust extractor and a table saw all day can easily come to more than the flat rate. Phone and broadband are outside both and claimed on their own business share.
Workshop machinery
A table saw, a planer-thicknesser, a spindle moulder, a bandsaw, a morticer, a dust extractor and a compressor are the plant of a joinery shop, and FileThat's box for plant and equipment is Repairs and maintenance. The cash basis writes the whole price off against the year the money leaves your account, so a £1,900 planer-thicknesser bought in a good year takes £1,900 off that year's profit rather than a slice at a time. A second-hand machine from a shop that is closing counts the same way. Having a motor rewound or the bearings replaced on a machine you already own belongs in the same box.
Site kit, blades and sharpening
The mitre saw and its stand, a track saw, routers and cutters, first-fix and second-fix nail guns, a cordless kit, a laser, clamps and the hand tools in the roll go under Repairs and maintenance alongside the machinery, each one written off in the year it is bought. Sharpening planer knives, bandsaw blades and chisels keeps kit you own cutting, so the grinding shop's invoice is Repairs and maintenance too. Replacement saw blades, router cutters, abrasives, nails and glue are used up as you work, and sit in Other expenses. Dust masks, ear defenders, safety glasses and boots belong in Other expenses with them.
Insurance, cards, drawings and finding work
Public liability, employer's liability if someone works with you, and cover for the van load and the workshop contents are Insurance. CAD or drawing software for setting out a staircase, a quoting app and whatever part of the mobile bill is for work are allowable, and the accountant's fee is Professional fees. Renewing the CSCS card that gets you onto a site is allowable, and goes in Other expenses. A website with photographs of finished pieces, a listing in a local directory and signwriting on the van are Advertising costs.
The rules behind every claim: allowable expenses for sole traders.
The van between the workshop, the yard and the site
A joiner's van carries 2.4 metre sheets, a staircase in sections and the mitre saw, and the cost of running it is claimed in one of two ways, fixed for as long as you keep that van: HMRC's flat mileage rates, 55p a mile for the first 10,000 business miles in the tax year and 25p after that, or the business proportion of its actual running costs, diesel through to tyres, recorded as Motor and fuel. Buy a van outright and its price can be deducted under the cash basis in the year of purchase, minus a share for any private use, but once that is done the van stays on actual costs and the flat rate is closed to it. A car's purchase price is not deducted in a lump like that.
Which journeys count turns on where the trade is based. Run it from a rented unit and the drive from home to the unit each morning is ordinary commuting, not a business journey; from the unit to a site, to the timber yard, to the ironmonger and to deliver a finished staircase, every mile is for the business. Run it from a workshop at home and the journeys to sites and suppliers start at your door. Two extensions and a loft conversion for a builder, each a few weeks, keep the site miles as business travel. A single job that fills most of a year, fitting out one building for one client, can be treated as where the business is carried on, so that getting there every morning is ordinary commuting.
Keep a log of each trip: the date, the destination, the miles. FileThat works a mileage entry out at the flat rates, and a van on actual costs takes a business-use percentage so only that proportion reaches the return.
Both methods, and the journeys that count, in detail: can I claim mileage.
CIS and VAT
First and second fix for a builder is CIS
Studwork, joists and roof carcassing, hanging doors, fixing skirting and architrave, fitting a staircase or a kitchen you did not make: all of it is constructing or altering a building, so when a builder, a developer or a main contractor pays you for it they take 20% off your labour, or 30% if you are not registered, and never off materials. Turnover is the gross figure before anything came off, and the deduction shown on each monthly statement the contractor hands you is typed into FileThat so that tax, already with HMRC, is set against your bill. Doors, hinges and timber you supplied come off before the 20% is worked out, provided your invoice shows them at cost; leave them off and the contractor may estimate what they were and deduct on the rest.
Made in the workshop and delivered: outside
HMRC's manual at CISR14100 says the manufacture of building components and their delivery are not construction operations, and its examples of components made off site include doors, a staircase, window walls, timber frames and floor panels. So a run of doors or a staircase you make in the unit and deliver to a developer's site for their own carpenters to fit is paid in full, even though the developer is a CIS contractor for everyone else on the job. The manual adds that it is the installation element of a contract that brings it within the scheme: make the staircase, deliver it and fit it yourself under one contract and the contractor deducts on the labour, with the cost of the timber and ironmongery, and anything you paid someone else to make, coming off first.
Homeowners and most other customers pay in full
A householder having sash windows made and fitted, a bespoke staircase installed or wardrobes built into the alcoves of their own home is never a contractor under the scheme, whatever the invoice comes to: they pay the lot, and the tax on it is dealt with through your return. A café wanting a counter, a shop wanting shelving or a landlord replacing a rotten door is outside too, unless that business's construction spending has passed £3 million in any 12 months. Fitted furniture is within CIS when a contractor pays for it: CISR14150 lists fitted bedroom furniture, fitted kitchens and shopfittings such as fixed shelving, counters and partitions, so wardrobes you fit in a developer's show home carry the deduction while the same wardrobes for the family next door do not.
VAT and the reverse charge
VAT registration becomes compulsory when taxable turnover over any 12 months, measured on a rolling basis, goes past £90,000, and the hardwood and ironmongery you charge on count towards it along with the gross amount a contractor paid before CIS, so a joiner who supplies the oak reaches the line on less labour than a fixer who only hangs the doors. Once registered, site work for a VAT-registered contractor under CIS normally comes under the domestic reverse charge: your invoice states that it applies, the contractor deals with the VAT, and in FileThat the sale is categorised as Construction industry - reverse charge sales. A staircase made and delivered without fitting is outside CIS and so outside the reverse charge, and homeowner commissions carry VAT in the ordinary way.
See what you could get back: the CIS refund calculator.
A joiner's year: workshop commissions, a builder, and doors sent out unfitted
Take a joiner in England renting a small unit, whose 2026-27 brings in £44,000 received from homeowners for staircases, sash windows and fitted wardrobes, timber included and nothing deducted. A builder, a CIS contractor, has them do the carpentry on a loft conversion and two extensions; the invoices show £20,000 of labour and £4,000 of doors, timber and ironmongery at cost, so the builder keeps back 20% of the labour, £4,000, and the joiner receives £20,000 during the year. A developer orders a run of internal doors made in the unit and delivered to site for its own carpenters to hang, £6,000 received in full because making and delivering components is not a construction operation. Turnover is £74,000.
Costs for the year: £19,500 of timber, sheet material, ironmongery and finishes; £7,200 of rent on the unit, with no business rates to pay under small business rate relief; £1,400 of electricity; £780 of insurance; £2,500 of machinery (a planer-thicknesser at £1,900 and a new extractor at £600); £700 of site kit; £450 of blades, cutters, abrasives and glue; £180 of sharpening; 6,000 miles between the unit, the sites, the timber yard and deliveries at the flat rate (£3,300); £240 of the mobile bill that is for work; £350 for the accountant; £200 on the website and a listing; and £160 of masks, ear defenders and boots. Together £36,960, leaving a profit of £37,040.
Taking off the £12,570 Personal Allowance leaves £24,470 taxable. Income Tax at 20% comes to £4,894, Class 4 National Insurance takes 6% of that £24,470, £1,468.20, and the year's total is £6,362.20. The builder has already sent £4,000 of it to HMRC, so £2,362.20 remains to be paid by 31 January 2028. That balance is £1,000 or more and the £4,000 at source is under 80% of the tax, so two payments on account towards 2027-28 of £1,181.10 each are due as well, the first with the balance and the second by 31 July 2028.
Three things change the shape of this year without changing the tax. Bill the builder £24,000 with no materials line and the deduction is 20% of all of it, £4,800, so the January balance falls to £1,562.20 and the payments on account to £781.10 each, the same £6,362.20 in total but with £800 more of it sitting with HMRC from the month the builder took it. Fit the developer's doors as well as make them and the whole contract comes inside CIS, with the deduction landing on everything but the cost of the timber and ironmongery, your hours at the bench included. Record none of the £36,960 of costs and tax and National Insurance on a £74,000 profit come to £19,768.60, part of it at 40%. Scotland sets its own Income Tax bands, so a Scottish taxpayer's figures differ slightly.
What you cannot claim
The jeans under the apron
A shop apron, safety boots, ear defenders and a dust mask protect you, so they count. The jeans, T-shirt and hoodie beneath them would do for the pub as well as the bench, which makes them private spending however much sawdust goes home in them.
A roll and a flask at the bench
Lunch eaten in the workshop or on a site within reach of home is food you would have needed anyway, and HMRC does not treat it as a cost of the trade. A meal becomes allowable when a job pulls you well outside your usual pattern, such as a fit-out far enough away to stay overnight.
Oak flooring for your own house
Timber for your own kitchen, wardrobes for your sister at cost, or a garden gate for a neighbour as a favour are private purchases even on the timber yard account. Put them through as disallowable and they leave the profit untouched.
Penalty notices, drawings and the tax itself
A penalty notice for unloading a staircase from the pavement, a speeding fine on the way to site, interest HMRC charges on late tax and what you draw to live on never reduce the profit, and neither do the Income Tax and Class 4 charged on it.
Each rule in detail: aprons, boots and the jeans beneath, the flask and the sandwich and journeys, parking and penalty notices.
Straight answers
Can I claim my workshop rent?
Yes. Rent on a unit used for the trade is wholly and exclusively a business cost, recorded as Rent, and the rates, electricity and insurance that come with it are allowable alongside it. A deposit the landlord will hand back when you leave is not an expense, because it is still your money. If you share a unit with another trade and split the rent, claim your share. The cost of buying a unit, or of building or extending one, is capital spending on premises that the cash basis does not deduct, which is why most joiners rent.
Is a planer-thicknesser tax deductible?
Yes, in full. Machinery used in the trade is equipment, recorded in FileThat as Repairs and maintenance, and the cash basis sets the whole price against the profit of the year it was paid, whether the machine cost £400 second-hand or £6,000 new. The same goes for a table saw, a spindle moulder, a bandsaw and the extraction that serves them. Fresh knives for the planer and sharpening the old ones are allowable too, as running costs of a machine you already own. The only machine-shaped purchase the cash basis refuses to deduct outright is a car.
Do I pay CIS on a staircase I make and fit?
It depends on who is paying and whether you fit it. For a homeowner, never: householders sit outside the scheme altogether, so they pay you every penny. For a builder or developer, HMRC's manual says making a component such as a staircase and delivering it is not a construction operation, so a staircase you make and drop at the site for their carpenters is paid in full as well. Fit it yourself under the same contract and the installation brings the whole contract inside: the contractor deducts 20% on the labour after the timber and ironmongery you bought come off, with the deduction entered in FileThat from their monthly statement.
How do I claim the timber offcuts I keep?
You already have. Under the cash basis the timber was an expense on the day you paid the yard for it, whichever job it was ordered for, so the offcuts in the rack and the half sheet of ply behind the door need nothing more recorded when they go into the next job, and there is no stock to count at 5 April. Two things do need a note. Offcuts you take home to burn in your own stove, or use on your own house, are private use of stock the business paid for, so mark a fair share disallowable. Offcuts you sell, as firewood or as short lengths to a hobbyist, are income of the trade.
My workshop is a building at the bottom of the garden. What can I claim?
The running costs, one of two ways. Either HMRC's flat rate for working from home, set by the hours you work there each month, which is £26 a month at 101 hours or more, or a proportion of the household bills: heating, electricity, Council Tax, and mortgage interest or rent, divided by the space the workshop takes up or the hours it is used for the trade. A machine shop running extraction and a saw for forty hours a week tends to do better on the proportion, so keep the electricity bills. The cost of putting the building up is spending on premises, which the cash basis does not deduct, though every machine inside it is deducted in the year you pay.
Most of my work is for homeowners. Do I still need to register for CIS?
Only once a contractor is going to pay you for construction work. Registration decides whether a builder or developer takes 20% or 30% off your labour, and a householder takes nothing off, so a year of staircases and wardrobes for private customers needs no registration at all. Making and delivering components without fitting them is outside the scheme too, so a developer buying doors from your workshop deducts nothing either. The moment a builder books you for first fix, register as a subcontractor before the first payment, or 30% of the labour goes to HMRC instead of 20% until you do.
Do self-employed joiners and carpenters have to use Making Tax Digital?
Yes, when qualifying income is above the threshold, which has been £50,000 since 6 April 2026, and falls to £30,000 from April 2027 and £20,000 from April 2028. Qualifying income means turnover before costs, counting self-employment and any property let together: the oak and ironmongery you charged on are in, and so is the gross amount the contractor paid before the deduction, so in the worked year above it is £74,000 that HMRC measures, not the £37,040 profit. The figure is read from a return already filed, so a year like that brings a joiner in at a later April, never the year it is earned.
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