If you are a self-employed plumber, your van is the backbone of your business. Every drive to a customer’s home, every trip to the plumbers’ merchant, every journey to pick up a replacement part — those miles add up fast. The good news is that HMRC lets you deduct vehicle costs from your taxable income, and getting the claim right could save you well over a thousand pounds each year.
This guide walks through everything a self-employed plumber or heating engineer needs to know about claiming mileage and vehicle expenses for the 2026/27 tax year, including how to choose between the two main methods and what Making Tax Digital means for your record-keeping.
Simplified Expenses: The 45p Mileage Rate
The quickest way to claim vehicle costs is HMRC’s simplified expenses method. Instead of tracking every receipt for fuel, servicing, and insurance, you multiply your business miles by a flat rate:
- 45p per mile for the first 10,000 business miles in the tax year
- 25p per mile for every mile above 10,000
This flat rate is designed to cover all running costs: fuel, depreciation, insurance, road tax, MOT, servicing, tyres, and repairs. You do not need to keep individual receipts for any of those — just an accurate mileage log.
The simplified method is available to sole traders and ordinary business partnerships. You cannot use it if you have already claimed capital allowances on the same vehicle, and once you start using it for a particular vehicle you must stick with it for that vehicle’s lifetime in the business.
On top of the mileage rate, you can still claim separately for parking fees, congestion charges, and tolls — these are not included in the 45p/25p rate.
Actual Costs: When Your Van Is Expensive to Run
The alternative is the actual costs method. Here you total up every penny you spend on the vehicle during the tax year — fuel, insurance, road tax, MOT, servicing, repairs, tyres, breakdown cover, lease or finance payments, and even the cost of washing the van — then multiply by your business-use percentage.
Many plumbers run panel vans that cost considerably more to fuel, insure, and maintain than an average car. If your annual van running costs are high, actual costs often produces a bigger deduction than the mileage rate.
You will also be able to claim capital allowances on the purchase price of the van itself. Vans qualify for the Annual Investment Allowance (AIA), which lets you deduct up to 100% of the purchase cost in the year you buy it — a significant advantage over cars, which are restricted to lower writing-down allowances based on CO2 emissions.
The trade-off is paperwork: you need to keep every receipt, calculate your business-use percentage carefully, and maintain a mileage log to support the split between business and personal miles.
Choosing the Right Method: A Real Example
Consider Sarah, a Gas Safe-registered plumber and heating engineer based in Leeds. She drives roughly 20,000 business miles per year in a three-year-old Citroen Berlingo van.
Simplified mileage method:
- 10,000 miles x 45p = £4,500
- 10,000 miles x 25p = £2,500
- Total deduction: £7,000
Actual costs method: Sarah’s annual van expenses break down as follows:
- Fuel: £3,800
- Insurance: £1,400
- Servicing and repairs: £950
- Road tax: £290
- MOT: £55
- Tyres: £320
- Finance payments: £2,400
- Total: £9,215
Sarah uses the van 90% for business, so her deduction is £9,215 x 90% = £8,294.
In Sarah’s case, actual costs gives her £1,294 more per year. At the basic rate of income tax (20%) plus Class 4 National Insurance (6%), that extra deduction saves her roughly £336 in tax and NI — worth having, but she needs to weigh that against the effort of keeping every receipt.
If Sarah’s van were cheaper to run — say total costs of £6,000 — the mileage rate at £7,000 would win. As a rule of thumb, the more expensive your van and the higher your mileage, the more likely actual costs will come out ahead.
What Counts as Business Mileage for Plumbers?
Not every journey qualifies. HMRC draws a clear line between business travel and commuting.
Claimable business mileage includes:
- Driving from your home (if it is your business base) to a customer’s property
- Travelling between jobs during the day
- Trips to plumbers’ merchants, trade suppliers, and wholesalers
- Driving to collect parts, materials, or equipment
- Journeys to training courses, Gas Safe renewal appointments, or CPD events
- Travel to your accountant, bank, or professional adviser
- Trips to tip runs or waste transfer stations for job waste
Not claimable:
- Travel from home to a permanent workplace such as a fixed office, workshop, or depot you attend every day — this is commuting
- Personal errands, even if made during a working day
Most self-employed plumbers work from home and travel directly to customers, which means almost every work journey is a claimable business mile. If you do have a separate workshop or lock-up that you attend daily, journeys between that fixed base and home are commuting and cannot be claimed.
Other Deductible Expenses Plumbers Often Overlook
Vehicle costs are usually the largest single deduction, but they are far from the only one. Self-employed plumbers can also claim:
- Tools and equipment — pipe cutters, wrenches, soldering kits, inspection cameras, pipe freezing kits
- Protective clothing — overalls, steel-toed boots, knee pads, safety goggles
- Gas Safe registration and renewal fees
- Public liability and professional indemnity insurance
- Trade body memberships — CIPHE, APHC, or similar
- Phone and broadband — the business proportion of your mobile and internet
- Training and CPD courses — including Unvented Hot Water and similar qualifications
- Accountancy fees
- Use of home as office — a flat rate of up to £26 per month under simplified expenses, or the actual costs of a dedicated room
Keeping track of both mileage and these expenses in one place makes tax time far simpler. Tripbook logs every journey automatically using GPS, so you always have an HMRC-ready mileage record without writing anything down.
Making Tax Digital from April 2026
From April 2026, Making Tax Digital for Income Tax (MTD for ITSA) becomes mandatory for self-employed individuals and landlords with gross income above £50,000. The threshold drops to £30,000 from April 2027 and £20,000 from April 2028.
Under MTD, you must:
- Keep digital records of all income and expenses using compatible software
- Send quarterly updates to HMRC summarising your income and costs
- File a final declaration by 31 January following the end of the tax year
For plumbers who are already busy juggling call-outs, quotes, and invoicing, the last thing you need is another admin burden. A GPS mileage tracker like Tripbook keeps your mileage records digital from the start — every trip is captured automatically, tagged as business or personal, and exportable in a format your accountant or MTD software can use.
For a deeper look at how the simplified method works, read our guide on HMRC simplified expenses for mileage. If you want to compare the two methods side by side, see actual costs vs mileage rate for the self-employed. And for a broader overview of sole trader claims, our sole trader mileage claim guide covers all the essentials.
Download Tripbook from the App Store and start tracking your plumbing miles today — setup takes under a minute, and every mile you log is a mile you can claim.
