P87 Mileage Claim Guide
Use P87 when your employer paid less than the approved amount and the claim sits outside Self Assessment.
At a glance
- Use P87 when you are claiming tax relief on job expenses and you are not putting the claim through Self Assessment.
- HMRC says claims of GBP 2,500 or less can be made online, by post, or by phone; larger claims go through Self Assessment.
- Mileage relief is based on the shortfall between the approved amount and what your employer already paid.
When P87 is the right route
P87 is for employees claiming tax relief on job expenses outside Self Assessment. For mileage, that usually means your employer paid less than the HMRC approved amount and you want relief on the gap.
The page to keep in mind is not 'how much did I drive' but 'how much of the approved amount was left unreimbursed'. If your employer already paid the full AMAP amount, P87 is not the route because there is no shortfall left to claim.
What to prepare before you submit
The friction on P87 claims usually comes from weak records, not from the form itself. Have the mileage totals, vehicle type, tax year, and employer reimbursement figures ready before you start.
- Keep a journey log with date, destination, business reason, and miles.
- Separate business travel from ordinary commuting before you total the year.
- Pull employer payslips, expense reports, or payroll summaries showing what was already reimbursed.
- Use the relief calculator first if you want the approved amount and shortfall laid out clearly.
When Self Assessment replaces P87
HMRC directs larger job-expense claims into Self Assessment. That is the main branching rule to remember when the claim value grows or your wider tax affairs already run through a tax return.
For most small mileage claims, the clean workflow is records first, shortfall second, P87 last. That sequence keeps the form as an output step rather than a guessing exercise.
Official references
Covers P87, claim routes, and the GBP 2,500 threshold.
Explains mileage allowance relief for employees using their own vehicle.
Continue with tools
Move from policy guidance into the calculator, rate page, or template that fits the same workflow.