There is no limit on foreign currency, traveler's cheques, etc. brought to Mongolia. Foreign currency must be registerd at Mongolian customs.
The Banks have a network of branch and exchanging bureau at most hotels. There are duty free shops where convertible currencies are accepted. In these a wide range of goods may be bought for foreign currency at favorable prices - typical Mongolian souvenirs, furs, cashmere garments, camel wool blankets, national costumes, horns, etc. in all other local shops only local currency is used. It is advisable to keep receipts as these may be required at customs on departure. Diners Club, American Express and Visa Card are accepted for payment at major hotels, shops, restaurants, bars and duty free shops.