I'm new to Upwork and might have my first project through this service. It's a project that takes place in another country and therefore there are travel costs (train and accommodation), which the client has agreed to pay for. Does Upwork also charge 20 percent on costs like that? Or only for the part of the payment that is part of my fee?
The fees apply to all amounts paid by the client. I would suggest that the client pays himself for your transportation and accommodation, and it would be safer for you since you don't know that client.