Currencies in Cuba
It is important that you gain a sense for both currencies, since it is not always clear whether the CUC or the CUP are being used, and the price is only given with a $ symbol. Rule of thumb is: in private restaurants, a Mojito or a Cuban beer will cost about 2-3 CUC, a pizza at the street vendor about 15 CUP (therefore approx. 0.60 CUC).
You can exchange money everywhere in Cuba. This can be done either in Cuban banks, in Havana for example you have the Banco Metropolitano, or alternatively the CADECA state exchange offices. Exchange rates at the banks are somewhat better anyway. Most important currencies can be changed, particularly advantageous are the Euro, the Swiss Franc, and the Canadian Dollar.
Tip: Avoid the US Dollar! You should absolutely avoid using US DOLLAR since there is a 10% fine for this, which can cause you an enormous financial loss.
Please note that there is a certain dress-code expected when you go to banks. Shorts, sleeveless shirts, and flip-flops are not quite welcome here.
Alternatively, tourists can also use their credit cards to get money in Cuba. The network of ATMs is relatively well spread in cities. The most efficient card is a VISA, irrespective of whether it is a prepaid or credit card. There can be problems with Mastercard; these usually only work at the bank counters. Cards of US banks cannot be used in Cuba. Take into consideration the costs that your bank exacts from you for any cash withdrawal.
You can find the current exchange rate at http://www.bc.gob.cu/ resp. http://www.cadeca.cu/en
Attention: changing money outside state-owned banks and exchange offices is completely forbidden and will be severely punished!