Hello, my name is Ben and it is my pleasure to assist you with your question today.
This is somewhat of a legal grey area. According to the Working Time Regulations 1998, ‘working time’ includes ‘any period during which a person is working, at his employer’s disposal and carrying out his activity or duties’.
According to guidance from the UK Department for Business, Innovation and Skills, the definition of working time also includes business travel time, but does not include home-to-work travel and time spent travelling outside normal working hours.
So if you are required to travel to/from clients as part of your working day and duties and at that time you are entirely at the employer’s disposal, you can certainly argue that this time constitutes ‘working time’ and should be taken into account when calculating your maximum working hours per week and your remuneration.