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MOD Mileage Tax Relief Calculator (HMRC rules)

Armed forces personnel using their own vehicle for duty journeys to temporary workplaces can claim tax relief on the difference between HMRC's approved rates (55p/25p from 2026/27; 45p/25p before) and any MOD mileage payment received.

Postings under 24 months normally count as temporary workplaces; permanent duty station moves do not.

Written by RefundCalculator Editorial TeamLast checked

Estimate your MOD mileage relief

Duty journeys in your own vehicle to temporary workplaces. Enter business miles per tax year and what the MOD reimbursed.

Vehicle
Tax years to include

Claims can go back four tax years. Each year uses its own rates.

Where do you pay income tax?

Service journeys that typically qualify

  • Travel in your own vehicle between a home station and a temporary duty location (under 24 months expected).
  • Journeys between bases, training areas and ranges during a posting.
  • Courses at another unit where you drove yourself and received nothing (or a partial rate) from the MOD.
  • Trips to ports/airfields for deployments where personal-vehicle use was authorised.
  • Never qualify: home-to-duty commuting to your permanent stationed base.

The 24-month rule that decides everything

HMRC treats a workplace as 'temporary' — and thus claimable — only if you are there (or expect to be) for under 24 months, and for under 40% of your working time when it's longer-running. Most service postings qualify on length; a permanent duty station never does. JSP 752 governs what the MOD pays you; HMRC's AMAP rules govern the tax relief on the gap between the two. The refund lives in that gap.

Evidence the claim actually needs

  • A journey log — date, start and end, purpose, miles. A notebook or spreadsheet kept at the time is ideal.
  • Posting or assignment orders showing the duty was temporary.
  • Any MOD allowances received (so the shortfall is calculated honestly).
  • Claims go through form P87 like any employee expense — four tax years back.

What this estimate can't tell you

  • Home-to-duty (commuting to your permanent station) does not qualify.
  • MOD allowances already received reduce the claim.
  • Eligibility of specific postings depends on length and orders — JSP 752 governs allowances, HMRC governs tax relief.

The free HMRC route

Everything this calculator estimates can be claimed directly from HMRC at no cost — usually online in a few minutes or via a short form. Refund companies charge a percentage of money that is already yours. We never handle claims and are not affiliated with HMRC.

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