HMRC to Publish Updated Company Car Fuel Rates in September

HM Revenue and Customs will publish updated Advisory Fuel Rates in September 2026 as part of its quarterly review process. These rates reflect average fuel costs and determine the amounts employers reimburse employees for business travel in company cars, as well as the repayments employees owe for private use of company-paid fuel.

Financial experts warn that relying on outdated rates can result in incorrect mileage claims and unexpected tax liabilities. Specifically, reimbursements that exceed the advisory rate without justification may become taxable, while under-reimbursement could potentially allow for tax relief.

Joe Lytwyn, a personal finance expert at thimbl.com, clarifies that these rates apply exclusively to company cars and not to employees using their own personal vehicles. To avoid complications, drivers are urged to maintain detailed mileage logs and verify their employer's mileage policies once the official figures are released in September.