Business Mileage Calculator

When you use your personal vehicle for business journeys, HMRC sets Approved Mileage Allowance Payments (AMAP) rates that your employer can reimburse tax-free. For cars and vans, the rate is 45p per mile for the first 10,000 business miles in a tax year, dropping to 25p per mile for each additional mile beyond that threshold. These rates are designed to cover fuel, insurance, wear and tear, and depreciation.

If your employer pays less than the AMAP rate, you can claim Mileage Allowance Relief (MAR) on the shortfall through your Self Assessment return or by contacting HMRC to adjust your tax code. The relief equals the difference between what HMRC allows and what your employer actually paid, multiplied by the number of qualifying business miles driven.

Commuting between home and your regular workplace does not count as business mileage. Qualifying journeys include travel to temporary workplaces, client sites, and locations that are not part of your ordinary commute. You must keep a contemporaneous mileage log recording dates, destinations, purposes, and distances for each claim.

HMRC Approved Mileage Allowance Payments (AMAP) 2026/27. Cars/vans: 45p/mile first 10,000 business miles, 25p/mile thereafter. Motorcycles: 24p/mile. Bicycles: 20p/mile. Passenger payments: 5p/mile each additional passenger. Rates unchanged since 2011 despite inflation — significantly undercompensates actual costs at 2026 fuel prices. Employers can pay LESS but employee claims tax relief on the difference.

What counts as business mileage. Travel between offices, client sites, training, meetings (excluding regular work location). NOT commute (home to permanent workplace). Detours from commute for business: only extra mileage above commute counts. Temporary workplace exception: assignments under 24 months to single site count as business if not your normal base.

How to claim. Employer pays AMAP rate or less: no further claim needed (already tax-relieved). Employer pays MORE than AMAP: excess taxable as benefit-in-kind via P11D. Employer pays LESS than AMAP OR nothing: claim relief on shortfall via P87 form (online) or Self Assessment. Self-employed: claim AMAP rates as business expense (simplified expenses method) OR claim actual costs proportional to business use.

Record-keeping requirements. Mileage log per journey: date, start/end postcodes, business purpose, miles. Apps like MileIQ, TripLog, QuickBooks Self-Employed auto-track via GPS. Records must be kept 5 years after Self Assessment filing. HMRC may request samples in compliance checks. Approximations don't satisfy — accurate mileage logs prevented many tribunal losses. Apps cost £5-£10/month, save hours of admin.