Today, Cuba currency is:
Cuban Peso is the currency used in Cuba, the national Cuba currency. It is the currency in which most Cubans are paid. It is equivalent to 100 centavos. The notes come in denominations of 1, 3, 5, 10, 20, 50, and 100 pesos. There are also coins for 1, 2, 5, and 20 centavos, and also 1 and 3 pesos. Coins for 1 and 2 centavos are now very rare.
Cuban Convertible Peso is valid only in Cuba. It comes in denominations of 1, 3, 5, 10, 20 and 50, and coins equal to 1, 5, 10, 25, 50 cents and 1 and 3 convertible pesos. It is basically tourist's currency in Cuba the one used at stores, most restaurants and in most places visited by tourists.
Since November 8, 2004, circulation of dollars and any other foreign currency was banned in Cuba and a 10% tax was established for the exchange of US dollars cash. This measure is applied not only to foreigners, but also to locals. So, you can exchange US currency in Cuba, but be aware that though 1 American Dollar equals about 1.08 Cuban Convertible Peso (CUC), you are charged an extra 10% tax if you exchange cash. This tax is not applied to any other foreign currency. So, I find it better to bring UK Pounds, Euros, Canadian Dollars or any other currency, except US dollars. You can exchange them in Cuba and if at the end of your stay you still have some convertible pesos left you can exchange them back.
Currency Exchange Office,
CADECA
You better don’t exchange money on the street; you can go to a bank or to one of the many currency exchange offices around. They are called CADECA (Casa de Cambio) in Cuba. At a CADECA you can buy and sell Cuban convertible pesos (CUC). One Cuban convertible peso equals $0.80 US dollars. If you want to buy Cuban pesos, one Cuban convertible peso is equivalent to 24-25 Cuban pesos.
However, when you travel to Cuba don’t forget that though Cuban Peso is Cuba national currency, tourists wouldn’t have many chances to use them, except for a bus or some fruits in the market. I don’t think you need to get any Cuban pesos at all.
You can also use credit cards in Cuba not only to pay for goods and services, but also to draw cash from ATMs, but make sure they are not issued by American banks or their branches. In Havana, there are ATMs in the banks, hotels, at some of the Exchange Offices (CADECAS) and generally every where around the city. In other main cities and resort areas such as Matanzas, Cienfuegos, Holguin, Santiago de Cuba, Varadero, it is also easy to find ATMs. Common credit cards accepted are: MasterCard, International Visa and CABAL. If you are planning to travel around the island and visit small towns, you better take cash with you.