Glazier
Tax & MTD Guide
CIS deductions and refunds, allowable tools, van and PPE costs, record-keeping, VAT and MTD for Income Tax explained for self-employed UK glaziers.
Estimate your tax as a self-employed glazier
Adjust the figures to see your estimated Income Tax and Class 4 National Insurance for the year.
Total turnover before expenses
Under £1,000 we use the trading allowance automatically
Estimated tax bill
£4,272
11.2% effective rate for 2026/27
- Income tax
- £3,286
- Class 4 NI
- £986
Take-home pay
£24,728
after tax, NI and expenses
This is an estimate using HMRC-confirmed rates for 2026/27, not your official tax calculation. TapTax is MTD-compatible, so you can connect to HMRC and file the real figures in a couple of taps.
- Glazing is a tools-and-van trade, so your biggest deductions are equipment, the vehicle, materials and insurance, and the biggest risk is letting CIS deductions sit unclaimed.
- Fitting glass for a building contractor almost always falls under the Construction Industry Scheme: register as a subcontractor so deductions stay at 20% rather than 30%.
- Because CIS takes 20% of your labour with no allowance for the personal allowance or expenses, most glaziers are owed a Self Assessment refund once van, tools and materials are deducted.
- You pay Income Tax and Class 4 NIC on profit, not turnover, so capture every receipt for sealant, beading, blades, fuel and PPE as you buy it.
- MTD for Income Tax starts April 2026 above £50,000 of gross income, April 2027 above £30,000 and April 2028 above £20,000, tested on turnover not take-home.
For a self-employed glazier the tax picture is shaped by two things: a vehicle full of expensive kit, and the Construction Industry Scheme quietly skimming 20% off your labour on every contractor invoice. Get both right and you usually finish the year owed money by HMRC rather than owing it. Get them wrong and you either overpay through unclaimed CIS deductions or under-record the materials and tools that should be cutting your bill.
Whether you are replacing a smashed shopfront on a high street, fitting double-glazed units in a new-build, installing curtain walling on a commercial job, or doing emergency board-ups, the money tends to arrive net of CIS, with materials flowing through your books and a constant trickle of spend on blades, sealant and fuel. This guide is built around how a glazier actually earns and spends, so the annual return becomes a reconciliation rather than a scramble.
How Tax Works for a Self-Employed Glazier
As a sole trader you pay Income Tax on your profit, which is your total glazing income minus allowable expenses, not on the gross amount a contractor pays you. 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 glaziers pay Scottish Income Tax 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 glaziers have a C-coded tax code at rates currently matching the rest of the UK. If you also do PAYE work for a fabricator or installer and your code looks wrong, run it through the tax code checker so you are not taxed twice on the same allowance.
CIS: The Big One for Glaziers
If you install glazing as part of construction or building work for a contractor, you almost certainly fall inside the Construction Industry Scheme. Fitting windows, glazed units, shopfronts, curtain walling, partitions and structural glass for a contractor counts as construction operations. The contractor must deduct money from the labour element of your invoice and pay it to HMRC on account of your tax.
- CIS deduction
- Under the Construction Industry Scheme, a contractor deducts a percentage from the labour portion of a subcontractor's invoice and pays it directly to HMRC as an advance payment toward the subcontractor's Income Tax and National Insurance. The rate is 20% if you are registered as a CIS subcontractor, or 30% if you are not. Materials, plant hire and VAT are excluded from the deduction, so itemise them separately on your invoice. The amounts taken are credited back at Self Assessment, where most subcontractors find they are owed a refund.
Two practical points decide how much CIS costs you up front. First, register as a CIS subcontractor so the rate is 20%, not 30%. Second, split labour and materials clearly on every invoice, because the deduction only applies to labour. If you bill £2,000 labour plus £1,500 for the glazing units, the deduction is 20% of £2,000, not the whole £3,500. Our full CIS subcontractor guide walks through registration, gross payment status and the statements you must keep.
Why You Are Usually Owed a Refund
The 20% deduction is a blunt instrument. It takes no account of your personal allowance, your van, your tools, your insurance or your materials. Once you deduct genuine business costs and apply the £12,570 personal allowance, your real tax bill on profit is frequently lower than the CIS already taken. At Self Assessment the deductions are credited against your Income Tax and Class 4 NIC, and the excess comes back to you. The CIS tax calculator shows the likely refund once your deductions and expenses are entered.
The one rule that protects this refund: keep every CIS payment and deduction statement from each contractor. Without them you cannot evidence what was withheld, and you risk losing the credit you are owed.
Allowable Expenses for Glaziers
An expense is allowable when incurred wholly and exclusively for the business. Glazing is equipment and vehicle heavy, so this list matters more than for most trades.
| Expense | What qualifies | Notes |
|---|---|---|
| Hand and power tools | Suction-cup lifters, glass cutters, beading and putty knives, cordless drills, sealant guns | Often claimed in full via the Annual Investment Allowance |
| Access equipment | Ladders, step-ups, scaffold towers, glass-handling trolleys | Larger items go through capital allowances |
| Van and vehicle | Purchase via capital allowances, plus running costs | Choose simplified mileage or actual cost, not both |
| Fuel and mileage | Diesel, or 45p per mile for the first 10,000 business miles then 25p | Commuting to a regular site is not allowable |
| Materials | Glazing units, sealant, beading, fixings, packers, putty | Deductible; on CIS jobs list these separately from labour |
| PPE and workwear | Cut-resistant gloves, safety boots, goggles, hard hat, logo workwear | Everyday clothing is never allowable |
| Insurance | Public liability, tool and van insurance, professional indemnity | Fully deductible business cover |
| Waste disposal | Removing and tipping broken glass and old frames | Keep tip receipts |
| Phone and admin | Business share of mobile, a fair home-office proportion for quoting and invoicing | Exclude the private share |
| Training and tickets | CSCS card, working-at-height and abrasive-wheels courses | Updating existing skills only |
| Accountancy and bank fees | Bookkeeping, Self Assessment, business banking | Fully deductible |
Tools, the Van and Capital Allowances
Big purchases such as a van, a scaffold tower or a full set of suction lifters are usually claimed through the Annual Investment Allowance, which lets you deduct the full cost in the year you buy, rather than spreading it. That can wipe out a large chunk of profit in a year you re-equip. For the van you choose one method and stick with it: either simplified mileage at 45p (then 25p over 10,000 miles), or the actual share of fuel, insurance, servicing, road tax and capital allowances on the vehicle. A glazier doing high mileage between sites should run both methods once and keep the larger.
What You Cannot Claim
The private share of a dual-use phone, van or fuel must be excluded. Everyday clothing is never allowable even if it gets wrecked on site, though branded workwear and genuine PPE are fine. Fines, parking penalties and the cost of your own driving licence are out. And ordinary commuting from home to a site you attend regularly is not deductible, even though travel between jobs during the day is.
Worked Example: A Glazier on £46,000 Turnover
Take a CIS-registered glazier doing mostly commercial shopfront and replacement work for contractors, with £46,000 of labour and materials billed for the year and £6,400 of CIS already deducted from labour.
Turnover: £46,000 (labour £32,000, materials £14,000)
Allowable expenses:
- Van running costs and capital allowance: £4,800
- Tools, suction lifters and access equipment (AIA): £2,200
- Materials bought for jobs: £9,000
- Public liability and tool insurance: £700
- PPE, workwear and waste disposal: £600
- Phone, home-office admin and accountancy: £900
- Total expenses: £18,200
Taxable profit: £46,000 minus £18,200 = £27,800
Income Tax: £27,800 minus £12,570 = £15,230 at 20% = £3,046
Class 4 NIC: £15,230 at 6% = £914
Tax and NIC due: £3,960. But £6,400 of CIS has already been deducted, so the glazier is owed a refund of roughly £2,440. Run your own labour, materials and CIS figures through the sole trader tax calculator to sanity-check the result before you file.
For a glazier, the CIS statements in the glovebox are worth more than any single invoice. Keep every one, deduct every tool and mile, and the tax year usually ends with HMRC owing you.
Record-Keeping on the Tools
Glazing record-keeping fails in the same place every year: receipts for sealant, blades, fixings and fuel that never made it out of the van. Build a habit of photographing each receipt the moment you pay, logging the mileage between jobs, and filing every CIS deduction statement as it arrives. Keep materials and labour separated on your own invoices so CIS is only ever applied to labour. Do this continuously and the annual return is a reconciliation, not an archaeology dig through a shoebox.
VAT and the Domestic Reverse Charge
You must register for VAT once taxable turnover passes £90,000 in any rolling 12-month period. Busy glaziers fitting commercial shopfronts and curtain walling reach this more often than they expect, especially when materials run through their books. Once registered, most construction services you supply to VAT-registered contractors fall under the domestic reverse charge: you do not add VAT to those invoices, and the contractor accounts for it instead. You must state on the invoice that the reverse charge applies and that the customer accounts for the VAT. Get this wording wrong and you risk charging VAT you should not, or losing it on a job where you should have. Work direct for private householders is normally standard-rated as usual.
MTD for Income Tax: What Changes for Glaziers
Making Tax Digital for Income Tax replaces the once-a-year return with quarterly digital submissions and a year-end finalisation. The thresholds are based on gross income, not profit and not take-home after CIS:
- April 2026: Combined gross trading and property income over £50,000
- April 2027: Over £30,000
- April 2028: Over £20,000
A subtle trap for CIS subcontractors: the threshold uses gross turnover before the 20% deduction, so a glazier taking home well under £50,000 after CIS can still be over the line on turnover. Instead of pulling a year of statements together each January, you record each invoice, material purchase and CIS deduction digitally as it happens and send HMRC a quarterly summary. Our guide to MTD for sole traders shows what the quarterly rhythm looks like on the tools.
Common Mistakes Glaziers Make
Not registering for CIS. Staying unregistered means 30% is deducted instead of 20%, tying up more of your cash with HMRC until you file.
Applying CIS to the whole invoice. The deduction is on labour only. List materials separately so the contractor does not over-deduct.
Losing the deduction statements. No statement, no evidence, no refund. File every one.
Mixing van methods. You cannot claim simplified mileage and actual running costs on the same vehicle in the same year. Pick one.
Judging the MTD threshold on take-home. It is measured on gross turnover before CIS and before expenses, so check your full billed income.
People also ask
Quarterly expenses under MTD: the £90,000 rule
If your annual business turnover is £90,000 or less, HMRC lets you report a single consolidated expenses total in each Making Tax Digital quarterly update instead of breaking expenses down into itemised categories. Most self-employed glazier businesses are under this threshold, so a quarterly update can be as simple as two figures: total income and total expenses. You still need to keep digital records of each individual expense - the relaxation only changes how much detail goes into the quarterly update itself.
Frequently asked questions
Calculators for glaziers
Helpful guides
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