Include the full job value, even the portion covered by a government grant, before materials and MCS costs are deducted.
If you're a self-employed heat pump installer, MCS-certified and fitting air source or ground source systems for homeowners, Making Tax Digital applies to you the same way it applies to any sole trader. This is one of the fastest-growing trades in the UK as households switch away from gas boilers, and grant-funded installs have a specific point worth understanding for MTD.
Yes, if your gross installation income, plus any other self-employment income, exceeds the relevant threshold:
| Tax Year Assessed | Threshold | MTD Start Date |
|---|---|---|
| 2024–25 | Over £50,000 | 6 April 2026. Live since April 2026 |
| 2025–26 | Over £30,000 | 6 April 2027 |
| 2026–27 | Over £20,000 | 6 April 2028 |
Your gross income is your total job value before expenses, the heat pump unit, materials, and MCS certification costs are all deducted afterwards, not before, when checking your threshold.
| Expense Category | Examples |
|---|---|
| Materials | Heat pump units, pipework, cylinders, and controls |
| Certification | MCS certification and scheme membership fees |
| Specialist tools | Refrigerant handling and commissioning equipment, via capital allowances |
| Vehicle costs | Van running costs or mileage, at the current HMRC rate |
| Insurance | Public liability insurance |
Owen's £61,000 includes the full value of every job, including the grant-funded portion. His combined income exceeds the £50,000 Phase 1 threshold, so MTD already applies to him.
Yes. The full job value, the portion covered by the grant plus whatever the homeowner pays, counts as your gross trading income. The grant simply changes who pays part of the bill, it doesn't change your total income from the job.
The same as any self-employed sole trader: over £50,000 gross income in 2024–25 means MTD from April 2026, over £30,000 in 2025–26 means April 2027, over £20,000 in 2026–27 means April 2028.
Yes, MCS certification and ongoing scheme membership fees are standard allowable expenses for this trade.
No, both are simply combined into one gross trading income total for your MTD threshold check, there's no separate treatment based on how the job was funded.
Any HMRC-recognised MTD software works. The main practical need is recording the full job value accurately, including grant-funded portions, which most trade invoicing software handles well.
Our free calculator checks your exact threshold, deadlines, and recommends the easiest software for your record-keeping.
Run Free MTD Check →