Nicaragua has its own currency: the córdoba. The US dollar is also virtually everywhere accepted. Often prices are based on dollars but quoted in córdobas. If you pay in dollars, you will receive your change in córdobas.
Prices in córdobas are given using the letter ‘c’ and a dollar sign (for example, C$100).
Credit cards are accepted in most stores, hotels, and restaurants throughout the country (not in little towns and off-road destinations). You can get cash from the ATMs, located in banks and gas stations.
Around the 15th and 30th of every month, banks are more crowded because people receive their paycheck on those days. Keep this in mind when you have to visit the bank. In general, the banking system in Nicaragua is old fashioned and slow. But if you only use the ATMs, you will not be bothered by this.