Business mileage rules: what actually counts
Most disputed mileage claims come down to one question: was that journey business travel or commuting? The rules are clearer than people expect, and the difference is worth hundreds of pounds a year.
Updated 14 October 2026
The basic rule
Business travel is travel you make in the performance of your duties, or to a place you have to attend for your job that is not your permanent workplace.
Ordinary commuting, home to a permanent workplace and back, is private travel and is never claimable, no matter how far it is.
Temporary workplaces, where most of the value is
A temporary workplace is somewhere you attend to perform a task of limited duration or for a temporary purpose. Travel there generally counts as business travel, including from home.
The 24-month rule: if you expect to spend, or actually spend, more than 40 per cent of your working time at a place for more than 24 months, it stops being temporary and becomes permanent. From that point the journeys become commuting.
The clock matters from when the expectation changes, not when the 24 months elapse. If a six-month contract is extended to three years, the travel stops qualifying from the date of the extension.
Journeys that do count
Driving between two workplaces in the same day.
Visiting a client, supplier or site.
Travelling to a temporary workplace, including from home.
A detour for business during an otherwise private journey. You claim the business portion.
Journeys that do not
Home to a permanent workplace.
A stop on the way to work, even for work reasons, if it does not materially change the journey.
Personal travel in a car you also use for business.
The mistakes that cost people the claim
Claiming the commute. The most common error by a wide margin, and the easiest for HMRC to spot: a claim showing the same mileage every working day, starting and ending at home, is a commute described as business travel.
Reconstructing the year in April. Estimates made months later are the weakest possible evidence, and if the figures are round numbers they look exactly like what they are.
Claiming actual costs as well. The approved rate already covers fuel, insurance, servicing, tax and depreciation. Claiming any of those separately on top is a duplicate claim.
Forgetting the threshold resets. The 10,000-mile band is per tax year, not per employment and not rolling, miles reset on 6 April.
Using the wrong rate for a van. Vans take the same 55p and 25p rates as cars, not the motorcycle rate. Motorcycles are 24p throughout, with no threshold.
Keeping it defensible
The strongest record is one made at the time, showing each journey separately with its purpose. A lump-sum estimate at the end of the year is the weakest.
Odomint records drives as they happen and lets you mark each as business or private, so the log exists before anyone asks for it.
Common questions
What is the 24-month rule for mileage?
A workplace stops being temporary once you expect to spend, or do spend, more than 40 per cent of your working time there for over 24 months. Travel then becomes ordinary commuting and stops being claimable.
Can I claim mileage from home to a client?
Generally yes, if the client site is a temporary workplace rather than your permanent one.
Do I need receipts for a mileage claim?
Not for fuel: the approved rate covers running costs. You need a record of the journeys themselves: date, route, purpose and distance.
Check any car before you buy it
MOT history, every advisory and the full mileage record are free for any UK registration. An Odomint Check adds outstanding finance, insurance write-offs, stolen markers and salvage history, with a £10,000 data guarantee.