The Eastern Caribbean dollar (EC$) is the island currency. US dollars are often accepted by taxi drivers and larger hotels - be sure when negotiating taxi fares and room rates that you are both talking about the same currency. Traveler's checks can be exchanged in banks and in larger hotels without issue.
Visa, American Express and MasterCard are widely accepted at hotels, car-rental agencies and high-end restaurants. You can get cash advances on your credit card through bank machines (provided your card has a security code or PIN). Also, bank cards that have either the Cirrus or the Plus symbol will usually work in bank machines. Royal Band and Scotia Bank readily accept foreign cards and are available inCastries and Rodney Bay.
An 8% tax and 10% service charge are added to the bill at all but the cheapest hotels and restaurants; there's no need for additional tipping.