Welder
Tax & MTD Guide
CIS refunds, allowable expenses for PPE, consumables and tools, mileage, VAT, National Insurance and MTD explained for UK self-employed welders and fabricators.
- Most self-employed welders working on construction sites are CIS subcontractors: the contractor deducts 20% from your labour, so the typical year-end outcome is a Self Assessment refund, not a bill.
- The 20% CIS deduction ignores your personal allowance and every expense, so claiming PPE, gas, consumables, tools and mileage properly is what unlocks your refund.
- Welding is a consumables-and-kit-heavy trade: wire, rods, discs, gas, PPE and the welder itself are all allowable, with big tools usually claimed in full via the Annual Investment Allowance.
- A fabricator who supplies materials as well as labour can cross the GBP 90,000 VAT threshold quickly, and most construction work falls under the VAT domestic reverse charge.
- MTD for Income Tax applies from April 2026 above GBP 50,000 gross, April 2027 above GBP 30,000, and April 2028 above GBP 20,000, tested on gross turnover before the CIS deduction.
For a self-employed welder, tax is rarely about a single big number. It is about two things working together: the Construction Industry Scheme taking 20% of your labour at source all year, and a long list of trade-specific costs that you must claim to get that money back. Get either wrong and you either overpay or leave a refund sitting with HMRC.
Whether you are a site welder on structural steel, a mobile fabricator doing repairs and one-off jobs, or a pipe welder moving between contracts, the same pattern repeats: gross payments come in net of CIS, your gas bottles and consumables drain cash weekly, and your kit is expensive. This guide is built around how welders actually earn and spend, so the annual return becomes a formality and your refund lands in full.
How Tax Works for a Self-Employed Welder
As a sole trader you pay Income Tax on profit, which is your total income minus allowable expenses, not on the cash that hits your account. For 2025/26 the personal allowance covers the first GBP 12,570, then you pay 20% 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, and Class 2 NIC is settled through your Self Assessment return.
Scottish welders 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 welders 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 wrong after a stint as an employee, run it through the tax code checker so you are not taxed twice on the same allowance.
CIS: Why Welders Usually Get a Refund
If you weld on building or construction sites for a contractor, you almost certainly fall inside the Construction Industry Scheme. The contractor deducts 20% from your labour payments (30% if you have not registered for CIS) and pays it straight to HMRC on account of your tax. That deduction is a blunt instrument: it takes no notice of your GBP 12,570 personal allowance, and no notice of the gas, wire, PPE, van and tools you bought to do the work.
The result is that the great majority of CIS welders have overpaid by the end of the tax year. When you file Self Assessment, your actual tax and NIC are calculated on your real profit, the CIS already deducted is set against that bill, and the excess is refunded, frequently a four-figure sum. Register for CIS to be deducted at 20% rather than 30%, keep every payment and deduction statement from each contractor, and read our full guide to CIS as a subcontractor for the registration and reclaim mechanics.
- CIS deduction statement
- A statement each contractor must give a subcontractor showing gross labour paid and the 20% (or 30%) deducted under the Construction Industry Scheme. You need these to prove how much tax has already been withheld so it can be offset against your Self Assessment bill and any overpayment refunded. Keep one for every contractor for every month worked; missing statements are the single biggest cause of delayed or under-claimed CIS refunds for welders.
To see roughly what your refund could look like before you file, put your gross labour and CIS deducted into the CIS tax calculator.
Allowable Expenses for Welders
An expense is allowable when incurred wholly and exclusively for the business. Welding is unusually expense-rich for a trade: protective gear is a safety necessity, consumables burn through fast, and the kit is costly. Claim it all and your profit, and therefore your tax, drops sharply.
| Expense | What qualifies | Notes |
|---|---|---|
| PPE and protective wear | Welding helmet, auto-darkening lenses, gauntlets, leathers, fire-retardant overalls, respirator, steel-toe boots, ear defenders | Fully allowable as protective clothing for the trade |
| Consumables | MIG wire, TIG and stick rods, electrodes, flux, gas (argon, CO2, mixed), contact tips, nozzles, cutting and grinding discs | Often your biggest weekly cost; keep every receipt |
| Welding plant and tools | MIG/TIG/stick welder, plasma cutter, grinders, clamps, generator, hand tools | Usually claimed in full via the Annual Investment Allowance |
| Van and travel | Van running costs or 45p/25p mileage, fuel, insurance, MOT, repairs, site parking, tolls | Choose mileage or actual costs and stay consistent |
| Equipment hire | Welding sets, access platforms or generators hired for a specific job | Fully deductible hire charges |
| Insurance | Public liability and tool insurance | Allowable business cover |
| Tickets and testing | Coding and ticket renewals (e.g. ASME, CSWIP), PAT testing of equipment, CSCS card | Allowable where required to keep working |
| Phone and admin | Business share of mobile, broadband and a fair home-office allowance for quoting and invoicing | Exclude the private share |
| Protective consumables | Welding blankets, fire extinguishers, gloves, anti-spatter spray | Allowable safety items |
| Accountancy and bank fees | Bookkeeping, Self Assessment, business banking | Fully deductible |
Tools and Plant in Detail
The welder itself, a plasma cutter, grinders and a van are capital equipment, but for most sole traders they are still claimed in full in the year you buy them through the Annual Investment Allowance rather than spread over several years. A GBP 2,500 TIG set or a GBP 12,000 van bought for the business can be deducted straight away, which on a strong year can knock your taxable profit down by thousands and, for a CIS welder, push your refund up. Keep the invoices: HMRC expects evidence for capital claims.
PPE and Protective Clothing
Everyday clothing is never allowable, even if you only wear it for work, but genuine protective and safety wear is different. A welder's helmet, fire-retardant overalls, leathers, gauntlets, respirator and steel-toe boots are all allowable because they protect you from the specific hazards of the trade. The cost of laundering or replacing heavily soiled protective clothing is allowable too.
What You Cannot Claim
The private share of dual-use van mileage, phone and broadband must be excluded. Ordinary commuting from home to a regular, single workplace is not allowable, though travel between sites and to temporary workplaces generally is. Fines, parking penalties and the cost of meals while working in your normal area are not deductible. And the personal portion of a van used at weekends must be taken out of the claim.
Worked Example: A CIS Welder on GBP 48,000 Gross
Take a full-time site welder paid GBP 48,000 of gross labour through CIS over the year, with the contractors deducting 20% at source.
Gross labour income: GBP 48,000 CIS already deducted (20%): GBP 9,600
Allowable expenses:
- TIG/MIG welder and tools (AIA, claimed in full): GBP 3,200
- Gas, wire, rods, discs and consumables: GBP 4,800
- PPE, leathers, helmet and boots: GBP 900
- Van running costs and mileage: GBP 3,600
- Insurance, tickets, PAT testing: GBP 700
- Phone, admin and accountancy: GBP 800
- Total expenses: GBP 14,000
Taxable profit: GBP 48,000 minus GBP 14,000 = GBP 34,000
Income Tax: GBP 34,000 minus GBP 12,570 = GBP 21,430 at 20% = GBP 4,286
Class 4 NIC: GBP 21,430 at 6% = GBP 1,286
Total tax and NIC due: GBP 5,572. But GBP 9,600 has already been taken under CIS, so the welder is due a refund of roughly GBP 4,028 once the return is filed. Run your own gross labour and expenses through the sole trader tax calculator to estimate your position before you submit.
For a welder, every gas bottle receipt and grinding disc you log is money back in your pocket. CIS takes 20% off the top all year, and your expenses are what claw it back at filing time.
VAT for Welders and Fabricators
You must register for VAT once taxable turnover passes GBP 90,000 in any rolling 12-month period. A site welder selling pure labour may never reach it, but a fabricator who supplies and fits steel, gates, balustrades or structural sections can climb past GBP 90,000 quickly because materials inflate turnover. If your customers are mainly VAT-registered builders and contractors, registration is fairly painless: they reclaim the VAT you charge, and you reclaim VAT on the van, plant, gas and consumables.
The catch for construction trades is the VAT domestic reverse charge. For most building and construction services supplied to another VAT-registered contractor, you do not charge VAT on your invoice; the customer accounts for it instead. You still show the work and note that the reverse charge applies. This affects cash flow and how you invoice, so flag it before your first reverse-charge job rather than after.
MTD for Income Tax: What Changes for Welders
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, and for a CIS welder that means turnover before the 20% deduction:
- April 2026: Combined self-employment and property income over GBP 50,000
- April 2027: Over GBP 30,000
- April 2028: Over GBP 20,000
This matters more for welders than many trades, because full-time site work often grosses GBP 40,000 to GBP 60,000, putting plenty of welders in the first or second wave. Instead of bagging up a shoebox of gas receipts and CIS statements each January, you record income and expenses digitally as they happen and send HMRC a summary every quarter. For a trade with weekly consumable spend and monthly CIS statements, capturing it continuously is genuinely easier than a year-end scramble. Our guide to MTD for sole traders walks through the quarterly rhythm.
Common Mistakes Welders Make
Not registering for CIS. Stay unregistered and contractors deduct 30% instead of 20%, tying up even more of your cash with HMRC until you file.
Losing CIS deduction statements. Without them you cannot prove how much tax was withheld, and your refund stalls or comes up short. Collect one from every contractor, every month.
Under-claiming consumables. Gas, wire, rods and discs add up to thousands a year. Welders who only keep the big receipts quietly overpay tax and shrink their refund.
Spreading tool costs instead of using AIA. Most welders can claim a new welder or van in full in the year of purchase, not drip it over several years.
Ignoring the VAT reverse charge. A fabricator who charges VAT on a reverse-charge job invoices it wrong and creates a mess to unwind later.
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