'Mileage (A to B)' settings

Go to Settings > Expenses > Expense types > Edit

By default, the Mileage (A to B) claiming process is not enabled. Click on Inactive for Mileage (A to B) to make it active.

Now click on Edit for Mileage (A to B) to add default costs per mile for each currency.

You can also add mileage costs on each staff profile for any special circumstance for different custom mileage rates per staff. Go to Staff profile > Rates tab and by adding a rate per mile here it will override the global rate for this person.