Tax · Expenses · 2026
The expenses tradespeople forget — and the tax they overpay
Most self employed tradespeople underpay their tax bills — not because they’re dishonest, but because they’re overclaiming nothing. They do the work, bank the money, and forget the hundred small costs HMRC would happily let them deduct.
01 · Why tradespeople lose money at tax time
It’s rarely dramatic. It’s usually a hundred small things — the bag of fixings from the merchant that never got written down, the three journeys to a job never logged as mileage, the annual trade membership fee sitting on a bank statement nobody looks at until January. The fix is a two-minute habit that runs alongside the job itself.
02 · The expenses most tradespeople miss
£4,400/yr on 8,000 miles. See how the 55p rate works.
Gas Safe, NICEIC, CSCS — 100% claimable every year.
The bag of fixings, tape, sealant — easy to forget individually.
Boots, hi-vis, gloves.
Most claim 50–75% of the bill.
Clearing a job site.
03 · The simple system that works
No complicated software, no hours of admin. A two-minute routine at the end of each job:
- Log the job — customer, price, date. Ten seconds.
- Log the mileage — miles driven, categorised as you travel.
- Photograph the receipt — add it to the expense entry.
- Mark it paid — once the money lands.
04 · Worked example · the mileage calculation most tradespeople don’t do
| Plumber — typical year | Figure |
|---|---|
| Business miles driven | 6,600 |
| Claimable at 55p/mile | £3,630 |
| Less tax to pay at 20% basic rate | £726 |
| Less tax to pay at 40% higher rate | £1,452 |
That’s not a rounding error. That’s a meaningful amount of money most tradespeople never claim, because the journeys are never logged.
05 · What you actually need to keep
HMRC doesn’t require the physical paper receipt any more — a digital copy, a phone photo, is sufficient. Keep records for five years after the January self assessment deadline for that tax year. In practice: photograph the receipt, add it to the expense in your app, and the paper can go in the bin.
06 · Cash flow is not profit
Quote a bathroom at £1,800 — but here’s where the money really goes:
| Cost | Amount |
|---|---|
| Materials | £500 |
| Labour (3 days) | £750 |
| Mileage | £45 |
| Waste disposal | £60 |
| Total cost | £1,355 |
Real profit on that £1,800 job: £445 — not £1,800. If you don’t track the costs job by job, you don’t know that number, and you might feel busy and productive while slowly underpricing yourself.
07 · What to look for in an expense app
Most expense apps are either too simple — just a list of amounts — or too complex, built for accountants not tradespeople. NicheApps builds job tracking and expense tools for specific professions — a plumber sees plumber cost categories, an electrician sees electrician job types. Free to start, no download needed. See Great Apps for Self Employed Tradespeople for the full lineup, or start directly with PlumberLog if you’re a plumber.
One final thought
The hardest part of tracking expenses isn’t the tracking — it’s starting. Log one job, add the mileage. It takes two minutes. Do that for a week and it becomes automatic.
This article is for general guidance only and does not constitute tax or financial advice. Always consult a qualified accountant for advice specific to your situation.