Making Tax Digital · Air conditioning engineers
Making Tax Digital for air conditioning engineers: do you need it?
170 days until it starts for sole traders over £30,000
Checked against GOV.UK, 14 October 2026.
The short answer for air conditioning engineers
A self-employed air conditioning engineer is over £30,000 of turnover on a few supply and fit installs, with the units and the pipework in the price, and the service contracts top it up every month. Over £30,000 for 2025 to 2026 means Making Tax Digital from 6 April 2027.
The thresholds, from GOV.UK (26 March 2026): over £50,000 for 2024 to 2025 started on 6 April 2026, over £30,000 for 2025 to 2026 starts on 6 April 2027, over £20,000 for 2026 to 2027 starts on 6 April 2028. All counted as turnover, before expenses.
The figure HMRC checks
HMRC checks your qualifying income: everything that came in from self-employment and property, before expenses. GOV.UK calls it turnover. Wages from a PAYE job don't count.
The figure is what you invoiced, not what landed in the bank. GOV.UK says the deductions a contractor takes count as advance payments towards your tax and National Insurance bill, and qualifying income is counted before expenses, so the 20% that came off is still part of your turnover.
A worked year, in air conditioning engineers' numbers
An air conditioning engineer took £67,000 in 2025 to 2026: splits and multi-splits for homes and small shops, servicing, and a fit-out contractor's job with £2,800 of CIS taken off. £31,000 went on units, pipework, brackets, refrigerant and the van. HMRC's figure is £67,000, so 6 April 2027 at the latest.
- Invoiced, before expenses
- £67,000
- Materials, costs, subbies
- £31,000
- CIS taken off by contractors
- £2,800
- What reached the bank
- £64,200
- HMRC's figure
- £67,000
Making Tax Digital from 6 April 2027 at the latest
Over £30,000 in 2025 to 2026 means 6 April 2027. If it was over £50,000 in 2024 to 2025 as well, it should have started on 6 April 2026.
Need it? Sort it in two minutes.
InstaQuote, 7 days free, then from £47 a month only if you carry on. ANNA opens from inside it, free for your first year. About 2 minutes.
- InstaQuote does the quotes, the invoices and the chasing.
- ANNA is the MTD software your updates go to HMRC through, free for your first year.
- You do the job.
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- ANNA gives you a personal tax calendar with reminders, so no quarter slips past.
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I'm Tom, the founder. Ten years in the trade, every quote done in the van. If it's not quicker than what you do now, bin it and tell me why.
AdInstaQuote: 7 days free, then from £47 a month only if you carry on. ANNA: £0 monthly fee to start, MTD for Self Assessment free for the first year, and a personal tax calendar with reminders (anna.money, 14 October 2026). InstaQuote may be paid by ANNA if you open an account through us. ANNA's terms apply.
CIS and air conditioning engineers
Installing ventilation systems is on GOV.UK's construction list, so a fit-out contractor or a builder paying you to install air conditioning deducts 20% from the labour. Shops, offices and homeowners paying you direct normally deduct nothing; if a contractor deducts on a service visit, their statement tells you. Every invoice counts in full towards your Making Tax Digital figure.
The rate, from GOV.UK: 20% if you're registered for CIS, 30% if you're not, nothing if you have gross payment status. Whoever deducts must give you a statement, and that statement is your proof.
The records air conditioning engineers lose
- Service visits at £90 a time for shop owners, paid by card on the spot and never raised as invoices.
- Units bought from the distributor on account, one statement across four installs.
- F-gas certification, refrigerant and the recovery machine, paid once a year.
Every three months your software sends HMRC totals for each income and expense category, not the receipts themselves. The updates are due on 7 August, 7 November, 7 February and 7 May, and each one covers the tax year so far.
InstaQuote holds those quotes, invoices and expenses as you work, so they can go into your Making Tax Digital software as the digital records. It isn't that software itself. ANNA, our partner, is the software your updates and return go to HMRC through.
Questions air conditioning engineers ask
Servicing is half my income. Does it count the same as installs?
Yes. It's all self-employment income, and the turnover HMRC checks is the total of both before expenses. Record every service visit as income the day you're paid.
A shop fitter took 20% off my install invoice. Is air conditioning really CIS?
Installing systems for ventilation is on GOV.UK's list of construction work, so a contractor paying you to install deducts. The deduction counts towards your tax, and your turnover is the gross amount.
Do business customers change anything for Making Tax Digital?
No. Whether the customer is a homeowner, a shop or a contractor, the money is income from your self-employment and adds to the same turnover. Only CIS differs, and only when the customer is a contractor.
Fifty service visits a quarter. Does HMRC want them listed?
No. GOV.UK says the update carries totals for each income and expense category, not the individual invoices. Each visit is recorded as income with its amount and date; the software sends one total.
I'm an air con engineer with a PAYE job for a facilities firm. Does that count?
No. GOV.UK leaves PAYE wages out of qualifying income. Only your self-employed work counts towards the £30,000 for 2025 to 2026, counted before expenses.
Can I get an exemption if I'm not good with software?
GOV.UK says the exemption is for people who are digitally excluded, applied for by phone or letter with the reason. If granted you still do a Self Assessment return. Whether you count as digitally excluded is HMRC's call, so if that's you, apply and explain why.
Does InstaQuote file my Making Tax Digital updates?
No. InstaQuote holds the quotes, invoices and expenses so they can go into your Making Tax Digital software as the digital records; it isn't that software itself. ANNA, our partner, is the software your updates and return go to HMRC through, from the business account you open inside your InstaQuote account.
Checked against GOV.UK
- GOV.UK: Check if you're eligible for Making Tax Digital for Income Tax (updated 26 March 2026)
- GOV.UK: Work out your qualifying income (updated 11 September 2026)
- GOV.UK: Use Making Tax Digital for Income Tax (updated 7 September 2026)
- GOV.UK: Send quarterly updates (updated 7 September 2026)
- GOV.UK: Penalties for Income Tax Self Assessment volunteers (updated 12 March 2026)
- GOV.UK: Penalties for Making Tax Digital for Income Tax (updated 30 March 2026)
- GOV.UK: Sign up for Making Tax Digital for Income Tax (updated 13 October 2026)
- GOV.UK: Create digital records (updated 7 September 2026)
- GOV.UK: Find software that's compatible (updated 13 July 2026)
- GOV.UK: Apply for an exemption (updated 17 August 2026)
- GOV.UK: CIS deductions from your payments (read 14 October 2026)
- GOV.UK: HMRC's Transformation Roadmap (no MTD for Corporation Tax) (updated 21 July 2025)
- GOV.UK: What is the Construction Industry Scheme (what counts as construction work) (read 14 October 2026)
- GOV.UK: What you must do as a CIS subcontractor (deductions) (read 14 October 2026)
- GOV.UK: What you must do as a CIS contractor (statements, monthly returns) (read 14 October 2026)
