MilometryPer diems: the other half of a business trip
The mileage is the part everyone remembers. The meals, the overnight stay and the incidentals are easy to forget, and they have their own rules.
Information générale, pas un conseil. Rédigé à titre d’information générale et exact à notre connaissance au 27 septembre 2026. Les règles fiscales changent et leur application dépend de votre situation. Ceci n’est pas un conseil fiscal, juridique ou financier : vérifiez auprès d’un expert-comptable, d’un conseiller fiscal ou de l’administration fiscale avant de vous y fier.
A day out to a client site can generate two claims, and it is easy to make only one of them. This post covers the rules for employees; the self-employed deduct travel and subsistence under different rules.
The two halves
Travel is the mileage. Business miles at the approved rate (for cars and vans, 55p a mile for the first 10,000 business miles in the tax year and 25p after, for journeys from 6 April 2026), plus tolls and parking on the journey.
Subsistence is what the trip cost you to be away: food, drink, and an overnight stay if there was one. It is a separate head of claim with separate rules, and it is where the money quietly leaks.
The reason it leaks is structural. The mileage is a calculation from a number you can look up. Subsistence is a pile of receipts, each individually too small to feel worth keeping, which collectively are not.
What actually qualifies
The test is that the cost was incurred because of a journey that is itself business travel. That does a lot of work.
A meal on a genuine business trip to a temporary workplace is claimable. Lunch at your normal place of work is not, however far you drove to get there, because the journey was not business travel in the first place.
So subsistence inherits the travel rules entirely. If the journey does not qualify, nothing that happened at the other end does either. This is why the commute and the 24 month rule matter twice over: they decide the mileage and they decide the meals.
Benchmark rates, and why they are convenient
HMRC sets benchmark scale rates that an employer may pay for meals on qualifying business travel free of tax and National Insurance: up to £5 after 5 hours away, £10 after 10 hours, and £25 after 15 hours if the journey is still going at 8pm. The travel must be business travel that is not substantially ordinary commuting, the employee must be away for the qualifying period, and the employee must have bought a meal after the journey started. Since 6 April 2019 the employer no longer has to check receipts, but it must have a system for checking that the employee was on qualifying travel. Anything paid above the rates, without a bespoke rate agreed with HMRC, is taxable.
The attraction is obvious: a fixed amount per qualifying absence and no reconciliation. One condition matters most: the employee must actually have bought a meal. The rate is a simplification of reimbursement, not an allowance you collect for having been out.
For travel outside the UK there is a separate published set of country by country rates, which is worth knowing about before anyone tries to convert a British figure into euros.
Overnight stays and the incidental allowance
An overnight stay on business brings the accommodation itself, plus a small tax free incidental overnight expenses amount an employer can pay for the things a hotel stay generates: a phone call home, a newspaper, laundry. The limit is £5 a night in the UK and £10 a night abroad.
It is deliberately modest, and it has a sharp edge. Exceed the limit and the whole amount becomes taxable, not just the excess. That is unusual in the tax system and it can catch employers who round the figure up to something tidier.
What to keep
| Mileage | Subsistence | |
|---|---|---|
| Evidence | A contemporaneous log | Receipts, or a benchmark rate |
| Rate published | Yes, approved mileage rates | Yes, benchmark scale rates |
| Depends on the journey qualifying | Yes | Yes, entirely |
The practical fix
The reason subsistence goes unclaimed is that the receipt and the journey get separated. The journey is in an app or a spreadsheet; the receipt is in a coat pocket, then a bin.
Attaching the cost to the trip it belongs to, at the time, is the whole solution. Milometry lets you add parking, tolls and other charges to the journey they came from with a photograph of the receipt, which is not a clever feature so much as the only arrangement that survives contact with a real week.
If your employer does not reimburse meals on genuine business trips, you may be able to claim tax relief on what you actually spent, provided you kept the receipts.
Sources
- Expenses and benefits: travel and subsistence (HMRC)
- Expenses and benefits: travel, what to report and pay (HMRC)
- Expenses rates for employees travelling outside the UK (HMRC)
- EIM30240: payments at a benchmark rate (HMRC manual)
- EIM30225: removal of the checking requirement from 6 April 2019 (HMRC manual)
- EIM05231: the earlier benchmark scale rates, to 2015-16 (HMRC manual)
- EIM02730: incidental overnight expenses, the permitted amount (HMRC manual)
- Travel, mileage and fuel rates and allowances (HMRC)
- Ordinary commuting and private travel (490: Chapter 3) (HMRC)
General information, not tax advice. Benchmark and overseas rates change: check the current figures with HMRC or your accountant.
