A salary sacrifice was a valid and binding contractual term, and subsistence payments under the scheme were round sum allowances, but the mileage payments and public transport payments under the scheme were not. 

A dispute arose between the appellants and HM Revenue and Customs (HMRC) about the income tax and National Insurance contributions (NICs) implications of payments made by the appellant under a salary sacrifice scheme made available to the appellant’s employees whose salaries generally exceeded the national minimum wage by £1, in respect of three categories of travel and subsistence expenses payments over the four tax years 2012/13 to 2015/16 inclusive: (1) payments in respect of mileage undertaken by participants in going to and from their temporary places of work by car, motorcycle or bicycle; (2) payments in respect of expenses incurred by participants in going to and from their temporary places of work by public transport; and (3)