There are Two Currencies in Cuba
There are two currencies in Cuba – a local currency (CUP) and tourist currency (CUC). As a tourist, you’ll use the CUC currency. However, in some remote places in Cuba, you may encounter the CUP currency. You can pay with this, but just understand that the exchange rate is different. At the time of writing, 1 CUC was worth 24 CUP.
Exchange your U.S. Dollars for Euro Before Your Trip
U.S. dollars are not accepted in Cuba and the only place you can exchange them is at the airport (sometimes). If the Cuban airport does allow you to exchange money, they will charge you a hefty tax. The best thing to do for money in Cuba is to travel with Euro in hand and then exchange your Euro once in Cuba. At the time of writing (March 2017), it was about a 1:1 ratio of Euro to CUC.