Self-Employed Plasterer
Tax & CIS Guide

Every pound deducted from your labour payments under CIS is real money HMRC is holding on your behalf, and for most self-employed plasterers those deductions add up to thousands of pounds a year. The single greatest financial lever a plasterer has at year-end is combining a full CIS reclaim with a thorough expense claim, and most people in this trade are leaving part of one or both on the table.

Skimming, rendering, dot-and-dab boarding, beading out openings: plastering sits squarely inside the Construction Industry Scheme as defined by HMRC. That means virtually every contractor you work for is legally required to deduct 20% from your labour payments before they pay you (or 30% if you have not registered under CIS). Understanding how that affects your actual tax bill, and how to get back what you are owed, is the core of your self-assessment year.

How Tax Works for a Self-Employed Plasterer

As a sole trader plasterer your taxable profit is your turnover minus your allowable expenses. That profit is then taxed through Income Tax and Class 4 National Insurance Contributions.

For 2025/26 the rates are:

CIS does not change these rates; it simply changes when HMRC receives the money. Instead of you paying a Self Assessment bill in January, the contractor has already forwarded 20% of your labour to HMRC throughout the year. Your job at year-end is to prove how much was deducted and offset that against your actual tax liability. If the deductions exceed what you owe, HMRC refunds the difference.

You can use the CIS tax calculator to see exactly how your deductions offset your bill before you file, and the sole trader tax calculator to model the full picture including your expenses.

Allowable Expenses for Self-Employed Plasterers

This is where plastering has a genuinely distinctive profile. Your materials are physically heavy, your kit is specialised, and your van is not a perk but a practical necessity. Every line below is an HMRC-allowable deduction that directly reduces your taxable profit.

Materials Versus Labour Under CIS

This distinction matters more for a plasterer than for many trades. CIS deductions apply only to your labour element, not to materials you supply. If a contractor pays you GBP 3,000 for a job that includes GBP 800 of plaster and beads, CIS should only be deducted from the GBP 2,200 labour portion. In practice some contractors deduct from the gross amount in error. Getting this right on every invoice protects your cash flow and avoids overpaying.

Van Costs: Mileage Method or Actual Costs?

With a van full of mixers, buckets and bags of plaster, your vehicle is core to your business. You have two choices: claim the HMRC approved mileage rate of 45p per mile for the first 10,000 business miles, then 25p per mile thereafter, using the mileage calculator; or claim your actual costs: fuel, insurance, servicing, repairs, road tax and depreciation (via capital allowances), with a deduction for any private use. For most plasterers with a dedicated work van and high annual mileage, actual costs usually win. However, you must pick one method and stick with it for the life of the vehicle.

Worked Example: A Plasterer on GBP 38,000 Turnover

Take a self-employed plasterer working entirely through CIS sub-contracts with a gross turnover of GBP 38,000 in 2025/26. Contractors have deducted 20% CIS on the full labour element throughout the year.

Assume the labour portion of the GBP 38,000 is GBP 30,000 and materials supplied to contractors account for the remaining GBP 8,000. CIS deductions: 20% of GBP 30,000 = GBP 6,000 already paid to HMRC.

Now the expense claim:

Taxable profit: GBP 38,000 minus GBP 9,520 = GBP 28,480.

Income Tax due: GBP 28,480 minus GBP 12,570 personal allowance = GBP 15,910 taxable at 20% = GBP 3,182. Class 4 NIC: GBP 15,910 at 6% = GBP 955. Total liability: GBP 3,182 plus GBP 955 = GBP 4,137.

CIS already paid: GBP 6,000.

Refund due from HMRC: GBP 6,000 minus GBP 4,137 = GBP 1,863.

Without a thorough expense claim, the taxable profit would be higher, the tax bill would be higher, and the refund would be lower or eliminated. Run your own numbers with the sole trader tax calculator.

VAT for Plasterers: When You Need to Register

If your taxable turnover exceeds GBP 90,000 in any rolling 12-month period you must register for VAT. Most plastering work on existing buildings is standard-rated at 20%. The important exception is zero-rated new-build residential construction: if you are brought onto a new-build house as a sub-contractor, the zero-rating may apply to your supply depending on how the contract is structured. This can affect your VAT recovery position significantly, so take advice before invoicing differently on a new-build site.

If you are VAT-registered you cannot reclaim VAT on materials you buy for a zero-rated supply in the same way as for standard-rated work, so the distinction genuinely matters to your cash position.

MTD for Income Tax: What Changes for Plasterers

Making Tax Digital for Income Tax Self Assessment (MTD for ITSA) will require sole traders with self-employment or property income over GBP 50,000 to submit quarterly digital updates to HMRC from April 2026, and over GBP 30,000 from April 2027.

For a plasterer with a turnover around GBP 38,000 the April 2027 threshold is the one to watch. From that date you will need to use MTD-compatible software to log your income and expenses and send four quarterly submissions per year, followed by a final declaration, rather than one annual Self Assessment return.

The good news is that the quarterly submissions are not four separate tax returns; they are summaries of income and expenses for the period. If you are already keeping records digitally, the extra admin is minimal. Read the sole trader quarterly submissions guide for a clear walkthrough of what each submission involves, and use the quarterly planner to map your submission deadlines against your site schedule.

Common Mistakes Plasterers Make on Their Tax Return

Not Keeping CIS Deduction Statements

This is the single most damaging error in the trade. Every contractor you work for as a CIS sub-contractor must give you a deduction statement showing the gross payment, the amount deducted for materials, and the CIS deduction taken. Without these statements you cannot prove to HMRC how much was deducted, which means you cannot offset those deductions against your tax bill. HMRC will not simply take your word for it. Chase every contractor for the statement the moment you receive payment. Store them digitally. If a contractor is slow to issue them, you are legally entitled to the statement within 14 days of the end of the tax month.

Claiming Materials Purchased by the Contractor

If the contractor supplied the plaster and you just applied it, you cannot claim the material cost as your expense. Only the materials you purchased yourself are deductible in your accounts.

Confusing Gross Turnover With Taxable Profit

CIS is deducted from your gross labour payments, but your tax is calculated on your net profit after expenses. A plasterer who sees GBP 6,000 of CIS deducted and assumes that covers their tax bill without accounting for the actual profit calculation will either over-refund-expect or underpay, depending on how the numbers fall.

Under-Claiming Van Costs

Many plasterers only claim fuel. The full actual-cost claim includes insurance, servicing, tyres, MOT, repairs and the capital allowance on the van purchase price. Overlooking these items is common and costly.

People also ask

Do self-employed plasterers have to register for CIS?

Can a plasterer claim plaster and materials as a business expense?

How does a self-employed plasterer get their CIS deductions back?

When does a plasterer need to register for VAT?