Concrete Finisher
Tax & MTD Guide

A self-employed concrete finisher lives by the slab. You arrive after the pour, work the surface as it goes off, ride the power trowel until the floor has the right sheen and hardness, and you only get one window to get it right. The tax side of the job has its own narrow window too, and it catches a lot of finishers out: nearly all your income arrives net of a 20% Construction Industry Scheme deduction, your real costs are heavy and constant, and the gap between what HMRC has already taken and what you actually owe is usually a refund waiting to be claimed.

This guide is built around how a concrete finisher genuinely earns and spends: CIS deductions and the refund they create, the specific tools, plant hire, van and PPE costs you can claim, how National Insurance stacks on top, the VAT reverse charge that confuses so many subcontractors, and when MTD for Income Tax lands. Get your records straight as you go and the annual return stops being a guessing game.

How Tax Works for a Self-Employed Concrete Finisher

As a sole trader you pay Income Tax on profit, which is everything you were paid for your labour and any materials, minus your allowable expenses. 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, with Class 2 NIC settled through Self Assessment.

The crucial point for a finisher is that CIS deductions are taken from your gross labour before any of those expenses come off, so the 20% already paid over to HMRC is almost always more than your final bill. That overpayment comes back as a refund once you file.

Scottish finishers 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 finishers have a C-coded tax code at rates currently matching the rest of the UK. If you also have a PAYE job and the code looks wrong, run it through the tax code checker.

CIS: The 20% Deduction and Your Refund

Concrete finishing is construction work, so the Construction Industry Scheme runs the whole money flow. When a contractor pays you, they verify your status with HMRC and deduct tax from the labour element of your invoice before it reaches your account.

Always register for CIS. Registered, you lose 20%; unregistered, contractors must take 30%, tying up even more of your cash until you reclaim it. The deduction only applies to labour, so if your invoice separately and genuinely itemises materials you supplied or plant you hired and recharged, those parts should not be deducted from. Keep every CIS payment and deduction statement the contractor gives you, because the totals on those slips are exactly what you offset against your final bill.

Established finishers with a clean filing and payment history can apply for gross payment status, where contractors pay you with no deduction at all and you settle everything through Self Assessment. It transforms cash flow but means you must keep enough back yourself for the eventual bill. Our CIS subcontractor guide walks through registration, statements and the refund mechanics in full, and the CIS tax calculator estimates what comes back.

Allowable Expenses for Concrete Finishers

An expense is allowable when incurred wholly and exclusively for the business. Unlike an office-based trade, a finisher's costs are dominated by tools, plant hire, the van and protective kit, and these are precisely what shrink your taxable profit below the level the 20% was calculated on.

Tools, Plant and the Van in Detail

Hand tools and consumables you use up are everyday running costs and come straight off your profit. Larger, longer-lasting kit, a quality walk-behind trowel you own rather than hire, is normally claimed in full in the year you buy it through the Annual Investment Allowance. Plant you hire by the day, like a ride-on trowel or laser screed for a warehouse pour, is a deductible hire cost; if you recharge that hire to the contractor it is income on one side and an expense on the other.

The van is usually a finisher's biggest running cost. You can either claim the simplified flat mileage rate or a fair business proportion of all actual running costs, but not both, so do the sum once and use the larger. Travel between different sites is allowable; the daily run to a site you treat as a regular base is ordinary commuting and is not. To pressure-test your own numbers, run them through the sole trader tax calculator.

What You Cannot Claim

Everyday clothing is never allowable even if it is ruined by concrete; only genuine protective and branded items qualify. The private share of your van, fuel and phone must be stripped out. Meals on an ordinary working day at a regular site are not deductible. And fines, parking penalties or the cost of getting set up before you actually started trading are excluded, though genuine pre-trading costs can be claimed once the trade begins.

National Insurance for Concrete Finishers

On top of Income Tax you pay Class 4 National Insurance at 6% on profit between GBP 12,570 and GBP 50,270, then 2% above that, all calculated and paid through your Self Assessment return. Class 2 NIC is also dealt with through Self Assessment and protects your entitlement to the State Pension and certain benefits, so it is worth checking it is being picked up even in a lean year. CIS deductions count only towards your Income Tax and overall bill, so NIC is part of what the refund calculation settles against.

VAT and the Construction Reverse Charge

You must register for VAT once taxable turnover exceeds GBP 90,000 in any rolling 12-month period. A busy finisher recharging plant and working long contracts can reach this, so keep an eye on the rolling figure rather than the tax year.

Once registered, the domestic reverse charge for construction usually applies to the labour you supply to other VAT-registered contractors. Instead of charging VAT and handing it over, you leave VAT off the invoice, state that the reverse charge applies, and the contractor accounts for the VAT themselves. You still reclaim VAT on your own costs: van, fuel, plant hire, tools and PPE. Because you are reclaiming input VAT but not charging output VAT on most jobs, reverse-charge subcontractors frequently sit in a regular VAT repayment position. The reverse charge does not apply when you supply an end user, such as a homeowner, who is not VAT-registered, in which case you charge VAT normally.

Worked Example: A Concrete Finisher on GBP 52,000

Take a CIS-registered finisher paid GBP 52,000 of gross labour across the year, all stopped at 20% by various contractors.

Gross labour income: GBP 52,000

CIS deducted at source (20%): GBP 10,400 already paid to HMRC

Allowable expenses:

• Van running costs and site travel: GBP 6,200
• Plant and machine hire (net of recharges): GBP 2,400
• Tools, consumables and curing compounds: GBP 2,100
• PPE and protective clothing: GBP 700
• Public liability and tool insurance: GBP 600
• Phone, admin and accountancy: GBP 900
• Total expenses: GBP 12,900

Taxable profit: GBP 52,000 minus GBP 12,900 = GBP 39,100

Income Tax: GBP 39,100 minus GBP 12,570 = GBP 26,530 at 20% = GBP 5,306

Class 4 NIC: GBP 26,530 at 6% = GBP 1,592

Total Income Tax and NIC due: GBP 6,898

Already paid via CIS: GBP 10,400

Refund due: GBP 10,400 minus GBP 6,898 = roughly GBP 3,502 back from HMRC. The refund exists because the 20% was taken on the full GBP 52,000 before any of the GBP 12,900 of costs were allowed. Keep every receipt and CIS statement and the refund is yours; lose them and you risk overpaying.

MTD for Income Tax: What Changes for Concrete Finishers

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 before CIS deductions and before expenses, not on profit:

• April 2026: Combined self-employment and property income over GBP 50,000
• April 2027: Over GBP 30,000
• April 2028: Over GBP 20,000

Because the test is on gross turnover, and the worked example above already shows a finisher above GBP 50,000, many full-time concrete finishers fall into the very first wave from April 2026. In practice you record each job, plant-hire ticket and fuel receipt digitally as it happens and send HMRC a quarterly summary through compatible software, then finalise. The upside is that your CIS statements and expenses are captured continuously, so the refund position is visible all year instead of being a January scramble. Our guide to MTD for sole traders shows what the quarterly rhythm looks like on the ground.

Common Mistakes Concrete Finishers Make

Not registering for CIS. Working unregistered means a 30% deduction instead of 20%, tying up even more cash until your refund.

Throwing away CIS statements. Those slips are the proof of tax already paid. Without them you cannot reliably claim the refund you are owed.

Forgetting plant-hire and fuel receipts. Day-rate trowel hire and constant fuel are big, legitimate deductions that drive the refund; lost tickets mean overpaid tax.

Claiming everyday clothing. Only genuine PPE and branded protective gear qualify, not ordinary clothes ruined on site.

Missing the VAT reverse charge. Charging VAT on labour to a VAT-registered contractor when the reverse charge should apply creates errors on both sides.

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