[Closed] Business mileage expenses and what to charge clients

An interesting topic came up for discussion today in the office and we're unable to come to a conclusion, anyone got an opinion or can say how it is done in their place of work?

The scenario; I work in the service industry where we are sometimes required to visit clients, regularly we will go straight to a clients site straight from home in the morning as this saves time over all on travelling.

So, what do we charge the client?

The return mileage from our office - regardless of where the staff member starts their journey from.

The mileage from my home to the clients and then back to my office.

The mileage difference between my commute to work and my travel to the clients and then the distance back to my office.

It seems that we've all been doing it slightly diffrently here!