mileage expenses claim rules for informal hybrid workers

An employee's contract states their placed of work is the company's office. There is no reference to hybrid working in their contract. The company has adopted a hybrid working policy whereby staff can choose to work from home (wfh) up to 2 days per week. Employees are free to choose which days they wfh and which days they work in the office. An employee visits a customer site on a day they chose to wfh. Do they deduct normal home to office travel from the mileage claimed on that day as they wouldn't have travelled to the office that day? Are the rules different on a wfh day from those that would ordinarily apply if it was a day they chose to work in the office (where normal home to office mileage would be deducted from any mileage claim)? Do they always have to deducted home to office mileage as their contract states their place of work as the company's office? Does it matter that they already worked in the office 3 days in that week, and this was on their final wfh day in the week.

Hi 

The rules are the same.  Home to office travel is not allowed for claiming expenses.  This travel would need to be deducted from any expenses claimed.

Thank you