🧱 Guide for builders · Updated 26 October 2026 · 6 min read

Measure twice, cut once. File four times a year.

It’s your pay before CIS deductions that counts: over £30,000 and Making Tax Digital applies to you from April 2027.

Countdown to Q2 quarterly update due

Saturday, 7 November 2026

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Already over £50,000? Your update for 6 July – 5 October has to reach HMRC by 7 November.

Making Tax Digital for builders: CIS, gross pay and quarterly updates

If you work as a self-employed builder or labourer – for a main contractor, for homeowners, or a mix of both – Making Tax Digital (MTD) for Income Tax is heading your way, if it hasn’t arrived already.

Builders on the Construction Industry Scheme (CIS) are caught out by one detail more than anything else: MTD looks at your gross pay, before the contractor takes 20% off. If £30,000 reaches your bank, your turnover for MTD is likely to be well over that.

Check if MTD applies to me →
In short: If you’re a self-employed builder and your takings (plus any rent) were over £30,000 before costs in the 2025/26 tax year, Making Tax Digital for Income Tax applies to you from 6 April 2027. Over £50,000 and it has applied since 6 April 2026; the threshold is planned to fall to £20,000 from April 2028. You’ll keep digital records in HMRC-recognised software, send four quarterly updates a year (due 7 August, 7 November, 7 February and 7 May) and file a final declaration by 31 January.

Are you in? It’s your takings, not your profit

Add up every invoice you raised in the 2025/26 tax year – labour and materials, for contractors and private customers – using the full amount before any CIS deduction and before you take off what you spent. If that total (plus any rent from property you let) is over £30,000, MTD applies from 6 April 2027. Over £50,000 and you have been in since April 2026.

April 2026

Over £50,000

April 2028

Over £20,000

planned

Your work in accountant language

What actually happens in your working life, what your accountant and HMRC call it, and what to do about it.

What happensAccountant calls itWhat you do
You invoice the contractor £1,000 for a week’s labourGross turnoverRecord the full £1,000 as income – this is the figure that counts for MTD.
The contractor pays you £800 and keeps £200 for HMRCCIS deduction (20%)Record the £200 as CIS tax deducted, not as an expense. Keep the monthly CIS statement.
The CIS statements pile up over the yearTax already paidTotal the deductions – they are taken off your tax bill in the final declaration, often leading to a refund.
A homeowner pays you for a garden wall, including the bricksTurnover (private work, no CIS)Record the full amount. Nothing has been deducted, so tax on this profit is still to pay.
You buy cement, blocks and sand at the merchantAllowable expense – materialsKeep the receipt or trade account statement; snap it into your app.
You buy a new mixer or SDS drillEquipment – deductible in the year you buy it (cash basis)Keep the receipt with the date you paid.
You take money out for the mortgage and food shopDrawings – not an expenseFine to do, but it doesn’t reduce your tax.
Every three monthsQuarterly updateYour software sends HMRC your gross income and expense totals.
After 5 AprilFinal declarationYour CIS deductions are set against the tax due; any balance or refund is settled by 31 January.

What can a builder claim?

✓ Usually allowable

  • Materials you buy for jobs – blocks, cement, timber, plasterboard, fixings
  • Hand tools and power tools, and repairs to them
  • Plant and tool hire, skip hire and waste disposal
  • Van running costs (fuel, insurance, servicing) or 45p a mile – not both
  • Protective clothing and boots, hard hat, hi-vis and gloves
  • Public liability and tools insurance
  • CSCS card, training and safety courses that keep your current skills up to date
  • Business share of your phone bill
  • Accountant’s fees
  • Parking and congestion or clean-air zone charges on jobs

✗ Not allowable

  • The CIS tax deducted from your pay – it is tax already paid, not a cost
  • Everyday clothes you also wear off site
  • Travel from home to a site you go to every day for a long job (more than 24 months)
  • Parking fines and penalties
  • Butties, brews and lunch on site
  • Money you take out for yourself (drawings)

Rules that matter for builders

Gross in, deduction separate

Under CIS a registered subcontractor has 20% taken off the labour part of each payment (30% if you are not registered). Materials are not deducted from. Your turnover is always the gross figure on the invoice; the deduction is recorded separately as tax already paid and set off against your bill in the final declaration.

Check your statements match

Contractors must give you a monthly CIS statement. Check each one against what you were paid – mistakes in your name or UTR mean the deduction may not line up with HMRC’s records, which can delay a refund.

Gross payment status

If you have gross payment status, nothing is deducted, so nothing is set off at the end of the year. That means the full tax bill is yours to pay – putting money aside each month matters more.

Paying a labourer yourself

If you take on other workers for construction jobs, you may become a contractor under CIS and have to verify them and make monthly returns. That is separate from MTD, but their pay is an expense in your records.

Worked example

Dan, a CIS subcontractor builder in Swindon (illustrative example)

Takings (turnover)£44,800
less Materials not supplied by the contractor−£4,200
less Van fuel, insurance and servicing−£4,900
less Tools and repairs−£1,500
less Plant and skip hire−£900
less Insurance, CSCS renewal and PPE−£850
less Phone (business share) and accountant−£1,100
Profit£31,350
Income tax (estimate)£3,756
Class 4 National Insurance (estimate)£1,127
Total tax for the year£4,883
Put aside each month£407

Estimate for 2026/27 using England, Wales & NI rates, assuming no other income. Scotland has different income tax bands.

What a quarterly update looks like

A typical quarter for a CIS builder: add up the gross amounts on your invoices, enter the CIS deducted from each monthly statement, add any private jobs, photograph merchant and fuel receipts – then submit through your software, or send it all to your accountant. Done after each monthly statement arrives, it takes about 20 minutes; left until the deadline, you are chasing missing statements from contractors.

QuarterPeriodSubmit by
Q16 Apr – 5 Jul7 Aug
Q26 Jul – 5 Oct7 Nov
Q36 Oct – 5 Jan7 Feb
Q46 Jan – 5 Apr7 May
Final declarationThe whole tax year31 Jan following

Quarterly updates are summaries – they don’t change when you pay. Tax is still due by 31 January (plus payments on account on 31 January and 31 July if they apply to you).

What will an accountant cost?

Typical monthly fees under MTD for Income Tax for: Construction trades (often CIS).

OptionWhat you getPer month
You do it yourselfMTD-compatible software. You keep the records and send the updates.£0–£15up to £180 a year
Accountant files for youYou keep records in an app; they check them, send the 4 quarterly updates and the final declaration.£35–£70about £420–£840 a year
Full serviceThey do the bookkeeping too – you share receipts and bank feeds, they handle the rest.£70–£130about £840–£1,560 a year

What pushes the price up: matching CIS statements and claiming back tax that was over-deducted; records kept on paper rather than in an app; being VAT-registered; catching up on missed updates or late returns.

What a fixed-fee quote should include

Accountancy fees for your business are an allowable expense, so they reduce your tax bill.

Indicative ranges from published UK price lists, checked October 2026. Not a quote – your fee depends on how many transactions you have, how tidy your records are and where you live.

Questions builders ask

The contractor already takes tax off. Why do I still need MTD?

CIS deductions are an advance payment, not your final tax. MTD is about reporting your full income and expenses. At the end of the year the deductions are set off against what you actually owe – often you are due money back.

Is my turnover what I received or what I invoiced?

For MTD and your tax return, it is the gross amount before CIS was taken off. A builder paid £36,000 after deductions may have earned £45,000 gross – and be over the threshold.

Do I record the CIS deduction as an expense?

No. It is recorded as tax already paid. If you put it in as an expense you would be claiming it twice.

Can I claim my van?

Yes, for the business use. You either claim actual running costs (and the van itself, under the cash basis) or use 45p a mile – you pick one method for that vehicle.

Sources

This guide is general information about HMRC’s Making Tax Digital rules as of 26 October 2026, not tax advice. MTD Match is an independent introduction service and is not affiliated with HMRC. Check gov.uk or speak to an accountant about your own situation.

Written by the MTD Match team

We turn HMRC’s Making Tax Digital guidance into plain English for each trade, cite the GOV.UK pages we rely on and update every guide when the rules change.

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