You can only use Cuban Convertible Pesos (CUC) inside Cuba. Convert other currency e.g., CAD or USD to CUC when you go in and convert what's left after your trip back to CAD or USD when you leave the country.
The rate from CAD to CUC is 1.31:1, and from CUC back to CAD is 1:1.21.
The rate from CAD to CUC is not very good, but if you convert from USD to CUC, you will be charged a special fee. I suggest you use credit card whenever possible.
Cuban people prefer USD as tips. You will find those 1 dollar US bills very handy.
