Tax · Self assessment · 2026
Most self employed plumbers underclaim. Not because they’re dishonest — because they’re not sure what counts. Here’s a plain-English breakdown of what HMRC actually allows, so you stop leaving money on the table every January.
Fuel, insurance, servicing, repairs, MOT, road tax — claim all of it if the van is used exclusively for work. Used personally too? Split the cost proportionally.
55p per mile for the first 10,000 miles, 25p after. Just log every business journey. See New 55p Mileage Rate 2026.
A plumber doing 8,000 business miles a year at 55p/mile can claim £4,400 in mileage alone. Most plumbers claim nothing because they never log their journeys. Full method comparison in Can I Claim My Van as a Self Employed Plumber.
Annual fees and renewals — 100% business, every year.
Purchases and repairs for tools used in your work.
Steel toe boots, hi-vis, knee pads, branded workwear.
Most plumbers claim 50–75% of their bill.
And professional indemnity if you carry it.
Courses to maintain or extend your qualifications.
Costs of clearing a job site.
Including apps like PlumberLog — a legitimate business expense.
From April 2026, self employed plumbers earning over £50,000 must switch to Making Tax Digital for Income Tax — quarterly digital updates instead of one annual return. Paper records won’t be accepted. Read the full breakdown in Making Tax Digital — What You Need to Know. The best way to prepare is to start tracking everything digitally now, even if you’re not yet over the threshold.
Most plumbers do their tax in one horrible weekend in January, going through bank statements trying to remember what every transaction was for. The fix is simple: log it at the time. Two minutes after a job is nothing compared to four hours of reconstructing a year’s worth of receipts. Do that for every job and your self assessment takes an hour at year end — see the full walkthrough in Self Employed Plumber Tax Return — Step by Step Guide.
This article is for general guidance only and does not constitute tax or financial advice. Always consult a qualified accountant or tax adviser for advice specific to your situation.