A bureau de change is a business which, in competition with other similar businesses, makes its profit by buying foreign currency and then selling the same currency at a higher exchange rate. It may also charge commission or fee on the purchase or sale. In setting its exchange rates, the business would keep an eye on changing market conditions, as well as the rates quoted by competitors, and may be subject to government foreign exchange controls and other regulations. The exchange rates charged at bureaux are generally related to the spot prices available for large interbank transactions, and are adjusted to ensure a profit. The rate at which a bureau will buy currency differs from that at which it will sell it; for every currency it trades both will be on display, generally in the shop window. The bureau sells at a lower rate from that at which it buys.