For 2026/27, the simplified-expenses mileage rate for cars and goods vehicles is 55p for the first 10,000 business miles, then 25p per mile. Motorcycles use 24p per business mile. You need a record of qualifying journeys and must be eligible to use this method for the vehicle.

The useful part is the journey log: where you went, why and how far. The rate can be applied later. Without the journeys behind it, a rounded annual total is difficult to explain.

Use the rate for the correct tax year

HMRC's vehicle guidance shows 55p for the first 10,000 business miles in 2026/27. Before 6 April 2026, the equivalent rate was 45p. The rate above 10,000 miles remains 25p.

Illustrative calculation: a sole trader with an eligible van logs 12,000 qualifying business miles in 2026/27. The first 10,000 at 55p gives £5,500. The remaining 2,000 at 25p adds £500. The total simplified vehicle expense is £6,000.

That is a deduction in the profit calculation, not a £6,000 payment from HMRC. The effect on tax depends on the trader's full position.

Make sure simplified mileage is available

The flat rate replaces the buying and running costs it covers. You cannot also deduct the same vehicle's fuel, insurance, servicing and repairs. Qualifying parking and other travel costs can be separate, but fines are not allowable.

You cannot start using simplified mileage for a vehicle whose purchase cost you have already deducted, or for which you have claimed capital allowances. Once you use flat rates for a vehicle, HMRC says to continue while you use it for the business. Check your earlier returns before switching methods.

HMRC's detailed motor-vehicle guidance covers the calculation and the change between tax-year rates. If your accounting period differs from the tax year, ask how the transition applies rather than selecting a rate from the payment date alone.

Record the purpose, not just the destination

A journey between customer jobs or a trip to collect materials can be business travel. Private travel and ordinary commuting do not qualify. The position for journeys from home depends on the facts of how and where the business operates.

Do not assume every drive to a site is allowable, or apply an employee's temporary-workplace rules to yourself without checking. HMRC's self-employed travel guidance is the starting point. Ask HMRC or an accountant about a regular base, long-running site or mixed-purpose journey.

Keep private detours separate. If you collect materials and then drive elsewhere for a personal errand, the business reason does not automatically cover the whole trip.

Keep a log you can understand months later

For each journey, record:

• the date and vehicle;

• the start and destination;

• the business purpose;

• the business miles;

• any note needed to explain an unusual route or split.

Example entry: “16 September 2026, job at Willow Road to merchant and back, collect agreed fittings, 8 business miles.” This is an illustrative record, not a claim about a real customer or a ruling that every similar trip qualifies.

Choose one place for the log and use the same method consistently. A diary can help check that journeys have not been missed. An odometer reading or mapped distance can support the recorded miles; neither explains the business purpose on its own.

Check the total before using it

Review entries against your diary, remove duplicates and make sure you have not included private trips. Keep supporting records for the required period. HMRC normally requires self-employed records for at least five years after the relevant 31 January filing deadline, with exceptions explained in its record-retention guidance.

TradePilot lets you log business journeys manually and review a mileage allowance for the selected tax year. It does not use automatic GPS tracking, decide whether a journey qualifies or submit the figure to HMRC. Check the record and tax treatment before using the total in a return.

Written by Chris, founder of TradePilot.

This is general information, not personal tax advice. Official mileage rates and guidance checked on 16 September 2026.