HMRC is due to publish its latest Advisory Fuel Rates from September, with the quarterly review potentially changing how much employers reimburse staff for business travel in company cars. What are HMRC's Advisory Fuel Rates? Joe Lytwyn, personal finance expert at thimbl.com, said: "HMRC's Advisory Fuel Rates are designed to reflect the average fuel cost of running a company car for business journeys." Instead, the Advisory Fuel Rates only apply to company cars. It's worth noting that the September rates have not yet been published, so drivers should continue using the current HMRC Advisory Fuel Rates until the updated figures are officially released.