Business mileage vs commuting mileage: the HMRC tests for locums

One of the most-claimed expenses for self-employed locums is business mileage. At 55p per mile for the first 10,000 miles and 25p after, a year of driving between sites adds up fast. The catch: HMRC distinguishes business travel from commuting, and the definition is tighter than most people assume.

The rule in one sentence

Travel between sites, and to genuinely occasional workplaces, is usually business travel. Travel between home and a place that has become a regular place of work is ordinary commuting and is not claimable.

The test that actually applies to you

There is no 24-month rule for the self-employed, and no 40% rule either. Both are employee rules, in section 339 of ITEPA 2003, and they are written about employees. If you are a sole trader they do not apply to you, and a locum who declines work to stay under 24 months is protecting a status they never had.

The self-employed test is whether the cost was incurred wholly and exclusively for the purposes of the trade, under section 34 of ITTOIA 2005. In travel cases that comes down to one question: is your work itinerant, moving between many sites with no regular base, or has a site become a regular place of work?

• Itinerant work: travel from home to each site is a cost of the trade and is claimable.
• A regular place of work: travel from home to it is ordinary commuting and is not.

HMRC's Business Income Manual from BIM37600 sets out the decided cases, including the ones about doctors travelling between home and hospitals. When in doubt, ask your accountant.

Examples:

• Locum GP working at seven different organisations in a year: itinerant. Travel from home to each site is business mileage.
• Locum pharmacist covering the same high-street pharmacy on Tuesdays and Thursdays every week, indefinitely: that branch is starting to look like a regular place of work, and travel to it looks like commuting. There is no month count that decides this; the pattern does.
• Locum physiotherapist who rents a clinic room one day per week: the rented room is a business expense, and the question for the travel is still whether the rest of the work is itinerant.

Travel from your main site to another one

Trips between two workplaces during the working day are always business mileage. A locum pharmacist covering a morning at one branch and an afternoon at another, the mileage between them is business. Home-to-first-site and last-site-to-home is separately assessed.

What counts as a workplace

Not just the clinical site. Anywhere you work for business purposes. For most locums that includes:

• The clinical site itself
• A site where you collect stock or equipment for business use
• A training venue where you attend CPD
• A mileage-counting visit to an accountant or legal appointment for business

Social visits do not count. Training that is not required for your work and not deducted as a business expense does not count.

Keeping records HMRC accepts

You need a log of every business journey with:

• Date
• Start location (usually home)
• End location (the workplace)
• Business purpose
• Miles

You do not need GPS evidence or receipts. Ordinary records are enough. But they must be contemporaneous, a spreadsheet written at year-end with "5 visits to Holbrook Medical" does not meet the standard if HMRC asks.

The 55p/25p split

• Cars and vans: 55p per mile for the first 10,000 business miles per tax year, then 25p per mile. The 55p rate applies to journeys made on or after 6 April 2026; journeys before that date are claimed at the old 45p rate, so a 2025/26 return still uses 45p.
• Motorcycles: 24p per mile flat, unchanged
• Bicycles: 20p per mile flat, unchanged

These rates cover fuel, insurance, road tax, MOT, servicing, depreciation, and finance. You cannot claim fuel on top, it is one or the other.

What you cannot claim

• Home to a site that has become your regular place of work
• Travel on days you are not working
• Travel that serves a social or personal purpose, even if work is incidental
• Fuel receipts alongside the mileage rate (pick one)

Practical discipline

1. Log the journey the day you do it, not the week after
2. Keep the log format simple, dates and miles, not running commentary
3. If one site is taking most of your working week, month after month, raise it with your accountant before the tax return, not after
4. At the end of each tax year, total business miles and check where you sit against the 10,000-mile step in the rates

The specific trap for locum pharmacists

Locum pharmacy sessions at a single branch week after week are the pattern most likely to look like a regular place of work rather than itinerant trade. That is a question about the shape of your working year, not a countdown, and it is worth a conversation with your accountant rather than a decision to turn down work. Mixing that booking with genuine other sites is what keeps the trade itinerant.

Sessional logs every shift with the workplace and distance. Total business miles for the year export to CSV in the format Self Assessment asks for. See our mileage calculator and expenses guide.

For information only, not regulated advice. Check with a qualified accountant or adviser.