Making Tax Digital
for plumbers
A self-employed plumber comes into Making Tax Digital for Income Tax on turnover, not profit — over £50,000 from April 2026, over £30,000 from April 2027, over £20,000 from April 2028. Because a plumbing trade buys materials on nearly every job, turnover runs well ahead of profit, which brings plumbers into the earlier bands than a look at take-home pay would suggest.
Self-employed plumbers and heating engineers trading in their own name, including those working under CIS on construction sites.
When it starts for you
HMRC phases this in by qualifying income — your self-employment and property turnover added together, before expenses.
| Qualifying income | Mandatory from | |
|---|---|---|
| over £50,000 | 6 April 2026 | In force now. |
| over £30,000 | 6 April 2027 | The next band. |
| over £20,000 | 6 April 2028 | The widest band. |
It is turnover, not profit, and it is added across all your sole trades and property together. Someone with £18,000 of trade income and £14,000 of rent has £32,000 of qualifying income, not two figures under the threshold.
What is different for you
The parts that catch plumbers out
Materials make the threshold arrive early
On a trade where parts are recharged to the customer, the money passing through is much larger than what you keep. Turnover of £38,000 with £15,000 of materials is a £38,000 qualifying income — inside the April 2027 band on £23,000 of gross profit.
CIS deductions still need recording
If you work as a subcontractor on construction sites, contractors deduct tax at source before paying you. Those deductions have to be tracked against your record so they set against the tax due, and the underlying invoices need keeping digitally like anything else.
The van is usually the second-biggest number
Between fuel, insurance, servicing and tools, vehicle running costs are often the largest expense after materials. Whether you claim actual costs or the simplified mileage rate, the records behind the claim have to be digital.
What actually changes
Digital records, kept as you go
Your income and expenses have to be recorded digitally rather than added up from a shoebox once a year. That is the part that changes day to day, and it is the part Revenue is built for.
Quarterly updates
Four updates a year per business, sent to HMRC from compatible software. They are running totals of income and expenses, not four mini tax returns, and no tax is due on them.
A final declaration
After the fourth quarter you finalise the year — adjustments, reliefs, anything outside the business — and declare it. This replaces the Self Assessment return you file today.
One set of books per business
HMRC treats a sole trade and a property business as separate businesses with separate obligations, even for the same person. Two income sources means two sets of quarterly updates.
Being straight with you
To be straight about where Revenue is today: it keeps your books on a real double-entry ledger and prepares the figures behind an SA return, but it does not yet send quarterly MTD for Income Tax updates to HMRC — that is in development, and our HMRC production approval is still in progress. If you are mandated now, keep your records in Revenue and file through an HMRC-recognised route until we can tell you otherwise. RepBud is designed to assist, not replace, your professional judgement.
Questions plumbers ask
When do plumbers have to start using Making Tax Digital?
It depends on turnover, not trade. If your qualifying income — self-employment and property added together, before expenses — was over £50,000 you are already in, from 6 April 2026. Over £30,000 brings you in from 6 April 2027, and over £20,000 from 6 April 2028. HMRC works this out from the return you have already filed, and writes to you.
Does this mean four tax bills a year?
No. A quarterly update is a running total of your income and expenses, sent from your software. There is no tax calculation attached to it and nothing to pay. Your tax stays due on the same dates it is now — the payment deadlines have not changed.
What if I am under the threshold?
Then you carry on filing Self Assessment as you do now, and nothing changes for you yet. It is worth knowing where you sit relative to the £20,000 band coming in April 2028, because qualifying income is turnover rather than profit and it catches more people than expected.
Can my accountant do it for me?
Yes. An agent can send quarterly updates on your behalf, and most people who use an accountant today will carry on the same way. What changes is that the records behind those updates have to be kept digitally through the year rather than assembled at the end of it — which is the half you can get ready now.
Also covered
Thresholds and dates are HMRC’s, checked August 2026. This is general information about the regime, not tax advice for your circumstances.