HMRC Mileage vs Actual Vehicle Costs: UK Sole Trader Guide

Vehicle expenses can be one of the largest tax deductions for a UK sole trader, but they are also easy to get wrong. The core decision comes down to two options: claim HMRC’s flat-rate mileage allowance or claim the actual running costs of the vehicle.

The best method depends on how much business driving you do, how expensive your vehicle is to run, and how detailed your bookkeeping routines are. This guide breaks down the rules in plain British English, including what HMRC allows, what it strictly forbids, and how to maintain a mileage log that holds up under audit.

Disclaimer: This article provides general tax information, not personalized accounting advice. If your vehicle usage or financing arrangement is complex, consult a qualified accountant.

1. The "Wholly and Exclusively" Business Travel Rule

Before choosing a calculation method, you must know which journeys legally qualify as business travel. HMRC requires all claimed expenses to be incurred wholly and exclusively for trade purposes.

Common Allowable Journeys:

• Visiting a client, customer, or business site

• Travelling to a temporary workplace or job location

• Driving to suppliers to pick up stock, tools, or raw materials

• Travelling to industry seminars, networking events, or accredited training courses

The Commuting Trap

Private travel is non-deductible. The most frequent mistake sole traders make is attempting to claim ordinary commuting.

If you drive from your home to the same permanent office, shop, or workshop every day, HMRC treats that trip as non-deductible personal commuting. However, if you are a mobile professional (e.g., an electrician, consultant, or courier) driving to varied, temporary job sites, those miles generally qualify as allowable business travel.

2. Option A: How HMRC Simplified Mileage Rates Work

Simplified mileage allows you to claim a fixed rate per business mile instead of tracking every drop of fuel, oil change, and insurance bill.

HMRC Approved Mileage Rates (2026/27 Tax Year)

Vehicle Type	First 10,000 Business Miles	Above 10,000 Business Miles
Cars and Vans	55p per mile	25p per mile
Motorcycles	24p per mile	24p per mile
Bicycles	20p per mile	20p per mile
Passenger Top-Up	+5p per passenger / per mile (for fellow business travellers)

(Note: HMRC updated the main flat-rate for cars and vans to 55p per mile for the first 10,000 miles, up from the long-standing 45p rate.)

What the Flat Rate Covers

The single flat-rate allowance is designed to cover all baseline running expenses, including:

• Fuel / EV charging

• MOT, servicing, and routine repairs

• Vehicle insurance and breakdown cover

• Vehicle Excise Duty (Road Tax)

• Vehicle depreciation

Warning: You cannot claim flat-rate mileage and separate fuel or repair receipts for the same vehicle. Doing so counts as "double dipping" and will trigger penalties during an HMRC compliance review.

Example Claim:

If you drive 8,000 allowable business miles in a diesel van during the tax year:

Claim = 8,000 miles x £0.55 = £4,400

3. Option B: How Actual Vehicle Costs Work

The actual costs method involves calculating the real operational costs of running your vehicle and deducting the business-use percentage.

Step 1: Calculate Your Business Split

Determine your total annual mileage and divide it by your business mileage:

Business Use % = (Business Miles / Total Miles) x 100

• Total Miles in Year: 20,000 miles

• Business Miles: 12,000 miles

• Business Use Percentage: 12,000 / 20,000 = 60%

Step 2: Sum Up Running Costs

Add together all eligible annual running costs:

• Fuel and electricity charges

• Servicing, MOTs, and replacement parts

• Insurance premiums and breakdown cover

• Road tax (VED)

• Commercial vehicle finance interest (excluding the capital repayment element)

If total running costs equal £6,000, your deductible expense claim is:

Business Claim = £6,000 x 60% = £3,600

What About Buying the Vehicle? (Capital Allowances)

The initial purchase price of a vehicle cannot be claimed as a standard day-to-day expense. Instead, it is claimed via Capital Allowances:

• Vans & Commercial Vehicles: Qualify for the 100% Annual Investment Allowance (AIA), allowing you to deduct the business proportion of the purchase price in Year 1.

• Electric Cars (Zero Emissions): Qualify for 100% First Year Allowances (FYA).

• Petrol/Diesel Cars: Deducted gradually using Writing Down Allowances (WDA) based on CO2 emissions.

4. Vehicle Financing & Leasing: HP vs Operating Leases

If you finance or lease your vehicle, how you claim expenses depends on the contract structure:

• Hire Purchase (HP) & Lease Purchase: You own the vehicle at the end of the term. You can claim the interest charges as an allowable expense (pro-rated for business use) AND claim Capital Allowances on the vehicle’s capital cost. Alternatively, if using simplified mileage, the flat 55p rate already covers loan depreciation and interest.

• Contract Hire / Operating Lease: You are renting the vehicle without ownership. You cannot claim Capital Allowances. Instead, you deduct the business proportion of the monthly lease payments as a running cost under the Actual Costs method. (Note: Cars with CO2 emissions exceeding 50g/km suffer a 15% lease rental disallowance)

5. Electric Vehicles (EVs) & Home Charging Rules

For sole traders driving electric cars or vans, the math gets interesting:

• EVs on Flat-Rate Mileage: You claim the standard 55p per mile. Because electricity costs per mile are significantly lower than petrol or diesel, high-mileage EV drivers often enjoy a generous tax deduction relative to their actual charging costs.

• EVs on Actual Costs: You can claim 100% First Year Capital Allowances on the purchase price of a new electric car or van. If charging at home, you must accurately calculate the kilowatt-hours (kWh) used specifically for charging the business vehicle to split off business electricity from your household bill.

6. VAT Registered Sole Traders & Fuel Reclaim

If your business is VAT registered, reclaiming VAT on vehicle expenses requires careful attention:

• If using Actual Costs: You can reclaim VAT on all fuel, repairs, and servicing, subject to paying the appropriate HMRC Fuel Scale Charge (if fuel is also used for personal trips).

• If using Simplified Mileage: You can still reclaim VAT on the fuel portion of your mileage claim! To do this, calculate the fuel element using HMRC’s Advisory Fuel Rates (AFRs) and keep corresponding fuel VAT receipts that cover at least the value of the fuel claimed.

7. The Critical "Vehicle Lock-In Rule"

This rule trips up thousands of sole traders every year:

The Vehicle Lock-In Rule: Once you choose to use simplified flat-rate mileage for a specific vehicle, you must stick with that method for as long as you use that vehicle for your business. You cannot swap back to actual costs in a later tax year just because you had expensive repair bills.

Conversely, if you claim actual costs and Capital Allowances on a car, you generally cannot convert that vehicle over to flat-rate mileage later on. You can only reset your choice when you completely replace the vehicle with a new one.

8. Simplified Mileage vs Actual Costs Compared

Feature / Question	Simplified Flat-Rate Mileage	Actual Vehicle Costs Method
Primary Calculation	Business miles $\times$ HMRC flat rates	Running costs $\times$ Business-use %
Record Keeping Needed	Mileage log book or tracking app	Mileage log, fuel receipts, invoices, & bills
Fuel Receipts Claimed?	❌ No (included in flat rate)	✅ Yes (pro-rata share)
Repairs & Insurance?	❌ No (included in flat rate)	✅ Yes (pro-rata share)
Vehicle Purchase Price	❌ No capital allowances permitted	✅ Claimed via Capital Allowances
VAT Reclaim on Fuel	✅ Yes (using Advisory Fuel Rates)	✅ Yes (subject to Fuel Scale Charge)
Ideal For...	Low-cost cars, lower mileage, simple admin	Expensive vans, high running costs, high business %
Method Switching?	❌ Locked in until vehicle is replaced	❌ Locked in once capital allowances are claimed

9. Separate Travel Costs You Can Still Claim

Whether you use flat-rate mileage or actual vehicle costs, you can claim the following standalone travel expenses, provided they are incurred wholly for business trips:

• ✅ Business-related parking fees (e.g., client parking lots)

• ✅ Toll roads, bridges, and tunnels

• ✅ Congestion Charges and Clean Air Zone (CAZ/ULEZ) charges

• ✅ Hotel accommodation and subsistence on overnight business trips

• ✅ Public transport tickets (trains, buses, taxis) used for work journeys

❌ Strict Exclusions (Never Claim):

• ❌ Parking tickets, speeding fines, or bus lane penalty charge notices (PCNs)

• ❌ Personal errands, school runs, or grocery shopping trips

• ❌ Ordinary daily commuting from home to a regular workplace

10. How to Maintain an Audit-Proof Mileage Log

If HMRC audits your tax return, an unverified estimate of your business mileage will be rejected. Build a quick daily logging routine using a physical logbook, a spreadsheet, or an automated GPS tracking app (e.g., MileIQ, QuickBooks, Tripcatcher).

For every single business journey, record these 6 details:

1. Date of travel

   
   

2. Start location & destination

   
   

3. Business purpose (e.g., "Site survey for Client X")

   
   

4. Total business miles driven

   
   

5. Associated expenses (parking, tolls, receipts attached)

   
   

6. Year-end odometer reading (crucial for establishing total annual mileage)