How long should I keep mileage records?

Up to 5-6 years

As a self-employed person or a company, you are required by HMRC to keep accurate mileage records of all your expenses as proof of the tax return.

HMRC can request any tax records from an individual up to 22 months after the end of the tax year, up to 5 years from the end of the tax year for the self-employed or partnerships, and up to 6 years from the end of the tax year for a company.