For self-employed engineers

MTD for Income Tax for gas & heating engineers.

Boiler installs with a big materials bill, service calls, warranty callbacks and a winter rush. Here's how Making Tax Digital for Income Tax applies to gas and heating engineers, and when it starts for you.

Does this apply to me?

If you turn over more than £50,000, it applies now.

MTD for Income Tax is measured on gross income before expenses. With boiler and parts costs passing through your invoices, install-heavy engineers cross £50,000 quickly.

Live now
£50,000
Gross income from April 2026
£30,000
Threshold from April 2027
£20,000
Threshold from April 2028
Installs inflate turnover

A big boiler job is big gross income.

The materials you supply for an install pass through your takings, so a run of installs pushes your gross turnover up fast, even though the margin is on the labour. That is exactly the figure the MTD threshold looks at.

What records you need
What's changing

Digital records, four quarterly updates, one final declaration.

Your annual Self Assessment return is replaced by four short quarterly updates and a year-end final declaration, all through recognised software.

Expenses to keep digital

  • Gas Safe registration and assessments
  • Van, fuel and running costs
  • Boiler parts, spares and stock
  • Tools and calibration equipment
  • Public liability insurance and workwear
  • Ongoing training and requalification

Log the merchant and manufacturer invoices as you buy so your install materials are matched to the right quarter.

  • Installs Large materials outlay against one invoice
  • Service calls Mostly labour, steady through the year
  • Winter spike Busy quarter reconciled at year-end
The engineer detail

The bits specific to your trade.

Gas Safe as an expense

Registration and assessment costs are business expenses. Keep them recorded and your deductible total stays complete.

Install materials

Record the boiler and parts you buy against the job. Big outlay in a quarter is normal, and your profit reflects the real margin.

Service vs install

Service calls are steady labour income; installs are lumpy. Both roll into one quarterly update automatically.

Warranty and callbacks

Parts under warranty and callback labour are all part of your records. Keep them logged so nothing is missed against a job.

Why Clear Books

Built for the van, not the office.

Between a service call and an install, the last thing you want is a spreadsheet. Clear Books lets you keep records from your phone and gives HMRC exactly what they need.

  • Record install and service income as you invoice
  • Snap manufacturer and merchant receipts for parts
  • Keep Gas Safe and insurance costs logged
  • Send HMRC-compliant quarterly updates in minutes
  • CIS support if you subcontract on construction sites
  • Free plan available, no timer
The Clear Books MTD for Income Tax submissions screen showing four quarterly updates submitted to HMRC
Q1 update submitted
HMRC recognised
Common questions

Gas & heating engineer MTD FAQ.

Do gas and heating engineers have to use MTD for Income Tax?
Yes, if you're self-employed with gross income over £50,000, it applies from 6 April 2026. The threshold drops to £30,000 from April 2027 and £20,000 from April 2028.
Is my Gas Safe registration a business expense?
Yes. It's a cost of running your business, so you record it digitally as a deductible expense alongside your insurance, tools and van costs.
How do boiler installs affect my quarterly figures?
A large install means a big materials outlay in one quarter. You record the materials as an expense and the full invoice as income, so turnover looks higher but your profit reflects the real margin.
My income spikes in winter, does that matter?
Quarterly updates reflect each quarter as it happens, so a busy winter is simply higher than a quiet summer. Your final declaration reconciles the year and tax is based on annual profit as before.
What else can I claim?
Typical costs include your van and fuel, tools and calibration equipment, boiler parts and stock, public liability insurance, workwear and ongoing training.
Free for sole trader engineers

Keep your books straight from the van.

Record installs and service calls as you go, snap your receipts, and send your first quarterly update in minutes.