Mileage Allowance Relief and Form P87: how to claim from HMRC
When your employer reimburses below the AMAP rate, you can claim the gap from HMRC. Here's how.
When MAR applies
Mileage Allowance Relief (MAR) is the tax relief available to UK employees whose employer reimburses business mileage at less than HMRC's AMAP rates (45p / 25p for cars, 24p for motorcycles, 20p for bicycles).[^hmrc-p87-79] MAR doesn't put cash in your pocket directly: it reduces your taxable income by the gap between AMAP and what your employer actually paid you.
Worked example
Sarah is an account manager. In tax year 2025/26 she drove 9,000 business miles in her own car. Her employer reimburses at 30p/mile (a flat "car allowance" company policy).
- AMAP eligible: 9,000 × 45p = £4,050. - Employer reimbursement: 9,000 × 30p = £2,700. - Eligible MAR: £4,050 − £2,700 = £1,350.
Sarah claims relief on £1,350. At her marginal rate of 20%, that's £270 back from HMRC. At higher rate (40%), £540.
How to claim
**Option A — through Self-Assessment.** If you already file a Self-Assessment return (rental income, self-employment, high earner), include MAR in the employment section.
**Option B — Form P87 (online).** Most PAYE-only employees use this route. Available at gov.uk/tax-relief-for-employees and submitted online with a Government Gateway account. You list:
- Tax year - Name and address of employer - Total business miles and AMAP-eligible amount - Amount actually reimbursed - Difference (the relief claimed)
If MAR + other expenses exceed £2,500 in a year, you must register for Self-Assessment instead.
Documentation HMRC may request
While you don't submit it with the claim, HMRC can request supporting evidence within 4 years:
- Mileage log with date, origin, destination, miles, business purpose. - Payslips or year-end summary showing employer reimbursement. - Any P11D entries related to the vehicle.
Quilometragem's digital receipts include all five fields plus an integrity hash, satisfying HMRC's contemporaneous-log standard.
Time limits
You have until 4 years after the end of the tax year to claim. So claims for the 2021/22 year had to be in by 5 April 2026.
Pitfalls
- Including commuting miles. Will be rejected. - Claiming when your employer pays AMAP or more (no relief available). - Mixing MAR with capital allowances on the same vehicle (you can't have both unless it's a self-employed activity). - Forgetting passenger payments. If you carry colleagues on business journeys, your employer can reimburse 5p/mile/passenger tax-free; you don't get separate MAR for this.
When MAR is significant
Flat car-allowance schemes (£4,800–£6,000/year) often work out worse for high-mileage drivers than AMAP-based reimbursement. If your business miles are above ~10,000/year and your allowance falls below 45p × first 10,000 + 25p × remaining miles, MAR can recover £500–£2,000 per year.
Bottom line
If you drive substantial business miles and your employer is below AMAP, MAR is one of the most overlooked reliefs in the UK PAYE system. Five minutes online and you reclaim hundreds.