The official currency in Bhutan is the Ngultrum. It holds the equivalent value as the Indian Rupee, which is also accepted in Bhutan. Occassionally, stores may also accept USD.
The Druk PNB Bank ATMs in Thimphu (near Clock Tower) and Paro (Sharee Square) accepts ANZ cards and dispenses local Ngultrums.
Generally only bigger tourist souvenier stores, restaurants and hoteliers accept credit cards. Small store fronts, supermarkets, local cafe, bars and restaurants are cash only.