Business Mileage Calculator

When you use your personal vehicle for business journeys, HMRC sets Approved Mileage Allowance Payments (AMAP) that your employer can reimburse free of tax. For cars and vans the rate is 55p per mile for the first 10,000 business miles in a tax year, dropping to 25p per mile beyond that threshold. The first-10,000 rate rose from 45p to 55p on 6 April 2026, announced on 21 May 2026 and the first change since 2011, while the 25p rate was left alone. Motorcycles are paid at 24p, bicycles at 20p, and carrying a colleague on the same business trip adds 5p per mile per passenger. The rates are meant to cover fuel, insurance, wear and tear and depreciation together, not fuel alone.

Employers are free to pay less than the approved rate, and many do. Where that happens you can claim Mileage Allowance Relief on the shortfall, worked out as the difference between the AMAP figure and what you were actually paid, multiplied by your qualifying business miles. Employees claim it on form P87 online or through Self Assessment, and HMRC can also collect it by adjusting your tax code. Paying more than the approved rate has the opposite effect: the excess counts as a taxable benefit and gets reported on your P11D.

Which journeys qualify is where most claims go wrong. Commuting between home and your regular workplace does not count, however far it is. Travel between offices, to client sites, to training and to meetings away from your normal base does count, and so does a temporary workplace, meaning an assignment expected to last under 24 months at a site that is not your permanent one. If you detour from your usual commute for a business call, only the extra mileage above the commute is claimable.

Self-employed people use the same rates from the other direction. You can either claim the AMAP figures as a business expense under the simplified expenses method, which keeps the paperwork light, or claim a proportion of your actual vehicle running costs based on business use. The two approaches cannot be mixed for the same vehicle, so it is worth working out which suits your mileage and your car before the first claim.

Records are the part HMRC actually checks. Keep a log for each journey with the date, start and end postcodes, the business purpose and the miles covered, and hold it for 5 years after you file the relevant Self Assessment return. Compliance checks routinely ask for a sample, and estimates reconstructed after the fact do not satisfy an inspector, which is how a good many tribunal cases were lost. Tracking apps such as MileIQ, TripLog and QuickBooks Self-Employed log trips automatically by GPS for £5 to £10 a month and remove most of the admin.