I know you get a refund on the deposit for an oyster card, but do you also get a refund of unused money put in for travel? Also, can you use the oyster card for travel in all zones of London and any mode of travel except taxi?
1) yes 2) yes 3) No, only on: Underground, Overground, commuter rail, DLR, Tram, bus (local only), and some River boats (using pay as you go only gets a discount on on route, pay as you go credit applied to paper ticket only, does not apply towards daily cap - read the fine print carefully). Oyster Cards are NOT valid on: Trains which are beyond the TfL zones, Rickshaws, mini cabs, black cabs, coaches, commuter buses, special buses, most river boats, tour buses,
ducks.
And only use cash for your Oyster card transactions--both the deposit and topping up--if you want an easy refund when you leave.