It is really difficult to explain the cuban currency because there are some things from Cuba that you must live to understand. Fidel Castro has revaluated the cuban currency in 8% from April 2005 on.

First of all you should know that most of the foreign currency trading (forex trading) websites provide the exact exchange from any currency to peso convertible.

Fidel Castro talked on March 24 about changes that took effect starting April 2005 and as he said that the Cuban peso convertible will be revaluated in 8%. Last year the Cuba government decided that the American Dollar was not accepted any more in Cuba. The direct consequences are not for tourists but for Cuban people. As a general view the new changes will be the following:
-- American dollar is not accepted on government business from Nov 8 2004 on(99% of Cuban places);
-- All stores that used to sell in American dollars changed to PESOS CONVERTIBLES (see below for the explanation of this term);
-- Pesos convertibles now cost the equivalent of $1.18 American Dollars (if you exchange dollars into pesos convertibles) because of the 10% penalty to USD and 8% of the revaluation of the CUC;
-- If you trade Canadian dollars or euros or any other strong currency into pesos convertibles the exchange 1.08 taking as reference the American dollar for example if 1 euro is 1,30 USD. son taking the 8% of the revaluation 1 euro is about 1.20 CUC.

So, according to a recent government regulation US dollar is not any more freely circulaing in Cuba from November 8th, 2004. The National Cuban bank has released the so called 'PESO CONVERTIBLE' in substitution of foreign currencies. You can acquire 'pesos convertibles' at the airport, banks and at the Money Exchange Offices, called "CADECA" (you can find these offices everywhere in the city). In addition, the American Dollar was not accepted any more in Cuba (18% less). However, the penalty of 10 % IS ONLY APPLIED TO US-dollars and NOT for any other foreign currencies such as Euros and Canadian dollars (among others). Other currencies than US-dollars will be exchanged according to the daily exchange rate of the international currency market. Taking into consideration the 8% of revaluation of the Cuban Peso Convertible.

In Cuba,  people trade every day with different foreign currencies and it is a normal fact for them the different foreign exchange currencies because the Cuban peso is very unstable and they use to exchange it every day. There are places that accept only Pesos Convertibles and other places only Cuban pesos. USD dollars are not any more accepted by the government business.

The national cuban currency is the Cuban Peso, which is equivalent to 100 centavos (cents). Notes can be of 1, 3, 5, 10, 20, 50 and 100 pesos. Coins can be of 1, 5 and 20 centavos, and there are others of 1 and 3 pesos.
The exchange to the Pesos convertible into American dollars is fixed, one to one to the equivalent of 1 American dollar, as established by the Central Bank of Cuba.

At the Money Exchange Offices (CADECAs) created for the population to sell - buy USD's or Cuban Convertible Pesos, the exchange can vary now between $24.00 and $26.00 Cuban pesos to the peso convertible. Once again you can visit websites about foreign currency trading to clarify the fact about trading pesos convertibles and knowing the exact exchange from any currency to Cuban peso convertible.

As you can see there is a big confusion for a traveler relative to the several currencies that are used in Cuba (Cuban currency).