Parts, tools, mileage — tracked in one app
Parts from Euro Car Parts, GSF, Andrew Page. Tools from Snap-on or Halfords. Mileage to every customer. All in one place.
Parts run by 9am, customer by 11am, parts run again by 3pm
A typical UK mobile mechanic visits motor factors 1-2 times per day, drives between 4-8 customer addresses, fills the van with diesel multiple times a week, and buys diagnostic kit and tools throughout the year. Receipts pile up in the van and disappear by year-end.
What PocketReceipt tracks for mobile mechanics
Motor factor receipts
Euro Car Parts, GSF, Andrew Page, Motor Factor, eBay parts. Vendor auto-recognised and tagged.
Van expenses
Diesel, insurance, MOT, repairs, breakdown cover. Choose simplified mileage or actual costs.
Diagnostic equipment
OBD scanners, scope tools, code readers, software subscriptions. Capital allowance flagged on big-ticket items.
Hand tools & tooling
Snap-on, Halfords, Sealey purchases. Tagged as tools, fully allowable.
Customer mileage
GPS or manual log to each customer. HMRC 55p/25p auto-applied. Multi-stop days handled.
Insurance & subs
Motor trade insurance, public liability, IMI / VOSA fees, trade-body memberships. All categorised.
A typical mobile mechanic's day, tracked
- 8:00am — fill van with diesel, scan receipt
- 9:00am — pick up brake pads from Euro Car Parts, scan invoice
- 10:00am — drive to customer, mileage logged
- 12:00pm — second motor factor run for an additional part, scan receipt
- 3:00pm — pay annual motor trade insurance, receipt forwarded
- Sunday — export weekly summary to your accountant
Allowable expenses for self-employed mobile mechanics
HMRC lets you deduct any cost that is wholly and exclusively for your mobile-mechanic business. The table below maps a typical sole-trader mechanic's spend — driveway services, brake-pad jobs, diagnostics, timing belts, AC re-gas — to the boxes on SA103F. Parts and a properly insured van are the biggest lines; diagnostic equipment and motor-trade insurance are the trade-defining ones.
| Expense | Claim? | SA103F box | Notes |
|---|---|---|---|
| Parts — engine oil, brake pads, discs, filters, spark plugs, batteries, tyres (when fitted) | Yes | Box 17 — Cost of goods bought for resale or goods used | Trade receipts from Euro Car Parts, GSF, Autodoc, Andrew Page, Halfords Autocentre. If you supply-and-fit, the part cost goes here. |
| Consumables — gear oil, brake fluid, threadlocker, sealant, copper grease, rags, blue roll | Yes | Box 17 | Anything used up on a job. |
| Used-oil disposal, bonded waste collection, tyre disposal fees | Yes | Box 17 / Box 30 | Environmentally compliant disposal is a real cost — claim every collection invoice. |
| Diagnostic scanner (Autel, Snap-on, Launch), code reader, oscilloscope, smoke machine | Yes | Box 49 — Annual Investment Allowance / cash basis expense | Under cash basis (default since 6 April 2024) include with other expenses. Under traditional accounting claim AIA, up to £1,000,000 a year. |
| Power tools — impact gun, drill, grinder, vacuum, work light | Yes | Box 49 / cash basis expense | Same treatment as diagnostic equipment. |
| Trolley jack, axle stands, transmission jack, spring compressor | Yes | Box 49 / cash basis expense | Capital equipment, but cash basis usually expenses it in year one. |
| Hand tools — socket sets, torque wrenches, spanners, screwdrivers, pliers | Yes | Box 22 — Repairs and maintenance of property and equipment | Replacement hand tools that wear out or get lost regularly. |
| Van — actual running costs (fuel, MOT, servicing, repairs, VED) | Yes | Box 20 — Car, van and travel expenses | Only if you are not using simplified mileage on the same van. Apportion any personal use. |
| Van — simplified mileage rate | Yes | Box 20 | 55p first 10,000 business miles, 25p after. Cannot be combined with actual costs or capital allowances on the same van. |
| Motor-trade insurance (covers your work on customer vehicles) | Yes | Box 21 — Rent, rates, power and insurance costs | Standard van insurance does NOT cover working on someone else's car at the roadside. Motor-trade cover (Road Risks + Public Liability) is mandatory in practice for mobile mechanics. |
| Tool insurance (in-van overnight cover) | Yes | Box 21 | Mobile mechanic vans are a known overnight theft target — diagnostic scanners and Snap-on sets are easy to move. |
| IMI (Institute of the Motor Industry) membership | Yes | Box 30 — Other business expenses | Listed by HMRC as an example of allowable trade body subscriptions. |
| F-Gas certification (air-conditioning regas work) | Yes | Box 30 | Refrigerant handling certificate — mandatory for AC work. Renewal fees allowable. |
| CPD — EV / hybrid awareness, diagnostics courses, ADAS calibration training | Yes | Box 30 | Refresher and extension training in your existing trade is allowable. Training in a completely new trade is not. |
| PPE — overalls, safety glasses, gloves, knee mat, steel-toe boots | Yes | Box 30 | Protective and specialist clothing only. Ordinary clothing is never allowable. |
| Workshop manuals — Haynes Pro, Autodata, Bosch ESI[tronic] subscription | Yes | Box 23 — Phone, fax, stationery and other office costs | Annual or monthly subscription, fully allowable. |
| Mobile phone bill — business proportion | Partly | Box 23 | Estimate honestly. 60–80% is typical for a mobile mechanic running booking and supplier orders through the phone. |
| Quoting / invoicing app, accounting software | Yes | Box 23 | Monthly subscriptions allowable. |
| Stationery — invoice book, business cards, printer ink | Yes | Box 23 | Day-to-day office consumables. |
| Advertising — Google Ads, Checkatrade, Trustpilot, leaflets, branded website | Yes | Box 24 — Advertising and business entertainment costs | Client entertainment is not allowable. |
| Card terminal fees (SumUp, Zettle, Square) on customer payments | Yes | Box 26 — Bank, credit card and other financial charges | Easy to miss — fees are netted off before money reaches your bank. |
| Accountant or bookkeeper fee | Yes | Box 28 — Accountancy, legal and other professional fees | Including the cost of preparing your Self Assessment. |
| Working from home flat rate (quoting, ordering parts, admin, scheduling) | Yes | Box 21 | £10 / £18 / £26 a month for 25–50 / 51–100 / 101+ hours business use. |
| Driving customer cars on the public road without trade insurance | No | — | Not a tax point — a legal one. Driving an uninsured-to-you customer vehicle is a criminal offence (uninsured driving). Trade-plates or Road Risks cover is required. |
| Lunch and food on the working day | No | — | Subsistence is only allowable on overnight trips away from your normal area. |
| Plain trousers, T-shirts, ordinary trainers | No | — | HMRC: "you cannot claim for everyday clothing (even if you wear it for work)." |
| Speeding fines, parking penalties | No | — | Fines are never allowable. |
Box numbers from HMRC SA103F Notes 2026. SA103S (turnover under £90,000) maps to the same expense categories on boxes 11–19, with Box 23 for AIA.
Karl, a Bristol mobile mechanic earning £58,000
The setup
Karl is 39, lives in Bristol and runs his mobile-mechanic business as a sole trader. All work is direct-to-customer — driveway services, brake jobs, diagnostics, timing belts, AC re-gas — invoiced from the side of the road, not through a main contractor. No CIS deductions at source. Gross turnover for 2025–26 is £58,000. He drives a 5-year-old Ford Transit Custom kitted out as a mobile workshop, 14,000 business miles a year, on actual-cost method (the van was bought through AIA two years ago).
What he claims at year end
Tracked through PocketReceipt across the year:
The maths
Gross turnover £58,000 minus £22,817 of expenses leaves a taxable profit of £35,183. After the £12,570 personal allowance, £22,613 falls in the basic-rate band. Income Tax at 20% is £4,523. Class 4 NICs at 6% on profits between £12,570 and £50,270 add £1,357. Total tax due: £5,880.
What it would have cost without the records
If Karl had only claimed the obvious — parts, van costs and his replacement diagnostic scanner, around £18,400 — his taxable profit would be £39,600. Income Tax would be £5,406 and Class 4 NICs £1,622, total £7,028. The records save him £1,148 a year, and the gap widens once Haynes Pro, F-Gas renewals and the tool-insurance premium come due.
Common tax mistakes UK mobile mechanics make
- Working on customer cars under standard van insuranceThis is a legal and a tax point. Standard van or private insurance does not cover working on someone else's vehicle. You need a Motor Trade policy with Road Risks + Public Liability. The premium is fully allowable in Box 21, but driving uninsured is a criminal offence and an invalid claim if something goes wrong.
- Mixing simplified mileage and actual van costs on the same vanPick one method per vehicle and stick with it for that vehicle's life with the business. Claiming 55p/25p AND fuel receipts is double-counting and HMRC will reverse it.
- Treating a diagnostic scanner or new van as "repairs"A £950 Autel diagnostic scanner, a £680 impact-gun replacement, or a new Transit Custom is a capital purchase, not a repair. Under cash basis (default since 6 April 2024) include the cost with other expenses; under traditional accounting it goes through Annual Investment Allowance — fully deductible in year one.
- Forgetting tool insurance is a separate allowable expenseMobile-mechanic vans are a real overnight theft target. Tool-specific insurance (covering kit left in the van) is a legitimate business expense in Box 21. Standard van insurance often excludes tools — read your policy.
- Skipping used-oil disposal and waste-collection invoicesBonded waste-oil collection, brake-fluid disposal, tyre and battery disposal — every collection invoice is allowable in Box 17 or Box 30. Across a year a busy mobile mechanic easily spends £150–£250 on environmentally compliant disposal.
- Plain clothes claimed as "work clothing"HMRC's rule is explicit: everyday clothing is never allowable, even if you only wear it for work AND even if it's covered in oil. Branded overalls, PPE, safety boots — yes. Plain joggers and old t-shirts — no.
- Treating new-trade retraining as CPDEV / hybrid diagnostics refresher, ADAS calibration training, F-Gas renewal, manufacturer-specific update courses — all allowable because they update your existing mechanic skills. A course in plumbing or electrics from scratch is not allowable as it's training in a new trade.
- Daily lunch and coffee claimed as subsistenceSubsistence is only allowable on overnight trips away from your normal working area. A meal deal between callouts is not a business expense.
- Missing card-terminal feesSumUp, Zettle and Square typically deduct 1.5–1.7% before money reaches your bank. Across £20,000 of card takings that's £300–£340 a year of pure expense relief, easy to miss because you never see the fee leave your account separately.
- Not reconciling parts wholesalers' end-of-month statementsEuro Car Parts, GSF and Andrew Page issue monthly statements showing every transaction. Reconcile against your receipt scans before filing — anything you bought on trade account that you can't find a receipt for is recoverable from the statement.
- Missing the 5 October registration deadlineIf you went self-employed in the 2025–26 tax year you must register for Self Assessment by 5 October 2026. HMRC can charge a "failure to notify" penalty calculated as a percentage of the tax due.
Year-end tax tips for mobile mechanics
- Time big tool and van purchases before 5 AprilA new diagnostic scanner, an oscilloscope, a smoke machine, transmission jack or replacement van bought before 5 April pulls the deduction into the current tax year. Under cash basis (default since April 2024) include them with other expenses; under traditional accounting they go through Annual Investment Allowance, up to £1,000,000 a year. Vans qualify for AIA in full; cars do not.
- Renew Motor Trade insurance + F-Gas before 5 AprilPay annual insurance and F-Gas certification renewal before 5 April to bring the deduction into the current tax year (under cash basis, the deduction lands when you pay).
- Decide simplified vs actual on the van — onceFor a fully depreciated van running 14,000+ business miles in a fuel-efficient diesel: simplified mileage might match or beat actual costs. For a brand-new £25k Transit Custom in its first year: actual costs plus AIA blows simplified out of the water. Pick the right method on the right year — you cannot switch on the same vehicle later.
- Reconcile parts wholesalers' monthly statementsPull the annual statement from Euro Car Parts / GSF / Andrew Page trade accounts before filing. Any trade-account purchase you can't tie to a job receipt is still allowable from the statement entry.
- Reconcile card-terminal totals against your bankPull the annual statement from SumUp / Zettle / Square. Gross takings go into turnover; processing fees go into Box 26.
- Check your Class 4 NIC band crossingFor 2025–26 Class 4 NICs are 6% on profits between £12,570 and £50,270, then 2% above. Successful mobile mechanics can drift past £50,270 — a well-timed equipment purchase before year-end can shift a chunk of profit out of the 6% band.
- Get ready for MTD ITSAFrom 6 April 2026, sole traders with combined self-employment + property income over £50,000 must file quarterly cumulative updates. The threshold drops to £30,000 from April 2027 — which catches almost every full-time mobile mechanic. First quarterly update for 2026–27 is due 7 August 2026, then 7 November, 7 February and 7 May, plus a Final Declaration on 31 January 2028.
- Watch the £90,000 VAT threshold rolling 12-month totalMobile mechanics doing high-value diagnostic jobs and tyre fitting can creep past £90,000. Check the rolling 12-month turnover each month, not just the tax year — late VAT registration brings penalties and back-VAT on sales you didn't add VAT to.
FAQ for mobile mechanics
Can I claim my diagnostic scanner?
Yes — diagnostic equipment used for the business is fully allowable. Items over £1,000 may be treated as capital allowances. PocketReceipt flags those automatically.
Are parts I supply to customers deductible?
Yes — parts are materials, fully allowable. Tag them to the job for accurate customer billing if you do flat-rate quotes.
Should I use simplified mileage or actual van costs?
Depends on miles. High-mileage mechanics (10,000+ business miles) sometimes beat simplified with actual-cost claims. PocketReceipt tracks both so you can compare at year-end.
Do I need motor trade insurance?
Yes — standard van or private car insurance does not cover working on someone else's vehicle. A Motor Trade policy with Road Risks + Public Liability is the standard cover for mobile mechanics and is fully allowable in Box 21. Driving an uninsured-to-you customer car on the public road is a criminal offence (uninsured driving) and an invalid claim if something goes wrong on the road.
When is my tax due?
Self Assessment for the 2025–26 tax year is due online by 31 January 2027. If your tax bill is more than £1,000 you also pay 50% as a first payment on account that day, and another 50% on 31 July 2027. From 6 April 2026, mobile mechanics with combined self-employment + property income over £50,000 also file quarterly MTD ITSA updates; the threshold drops to £30,000 from April 2027.
Tools — do I expense them or claim capital allowance?
Under cash basis (the default since April 2024), tools are deducted in full in the year you buy them — Box 20 (repairs and renewals) on SA103S. Under traditional accounting, larger purchases usually go through Annual Investment Allowance (Box 49 SA103F). Either way it's a 100% year-one deduction up to the £1m AIA cap.
Can I claim a mobile workshop fit-out (shelving, lighting, generator) in my van?
Yes. Fixed van fit-outs are claimable in the year you fit them. If you later sell the van with the fit-out, you account for the disposal value — PocketReceipt's exports flag this for your accountant.
Workwear, overalls and boots — what's allowable?
Branded overalls, safety boots, gloves, eye protection, ear defenders — all 100% deductible as PPE. Plain trousers and t-shirts, even if you only wear them for dirty work, are not deductible. HMRC publishes this rule: 'you cannot claim for everyday clothing.'
Diagnostic software and subscriptions (AlldataDIY, Autodata, ICarsoft updates)?
Yes — fully deductible. Subscription updates and online manuals used for paid jobs go in Box 27 (other business expenses) on SA103S. The laptop or tablet you run them on can also be claimed, apportioned for any private use.
HMRC and PocketReceipt references used on this page
- HMRC, Expenses if you're self-employed — overview
- HMRC, Clothing expenses
- HMRC, Simplified expenses — vehicles (55p / 25p / 24p flat rates)
- HMRC, Simplified expenses — working from home
- HMRC, Annual Investment Allowance
- HMRC, Cash basis accounting (default since April 2024)
- HMRC, Self-employed National Insurance rates
- HMRC, Self Assessment deadlines
- HMRC, Making Tax Digital for Income Tax
- HMRC, SA103F Notes 2026 — Self-employment (full) (PDF)
- PocketReceipt, Mileage calculator · VAT threshold calculator · MTD Forecaster
- PocketReceipt, Sole-trader allowable expenses — full guide · Simplified vs actual costs · MTD ITSA quarterly checklist
- PocketReceipt, Which receipt scanner app is best? 7 compared
Worked example figures are illustrative. Tax rates use 2025–26 thresholds: personal allowance £12,570; basic-rate Income Tax 20%; Class 4 NICs 6% on profits between £12,570 and £50,270, 2% above. PocketReceipt is a record-keeping app, not a tax adviser — speak to an accountant for advice on your situation.