St Lucia is not cheap, and you'll pay US and European prices for restaurants and accommodation. St Lucia's official currency is the Eastern Caribbean dollar (EC$), which trades against the US dollar at an official rate of EC$2.70 to US$1 for travellers' cheque exchanges, slightly less for cash conversions. In the case of hotels, car rental, restaurants and practically everything related to tourism, most prices in St Lucia are quoted in both EC and US dollars, and occasionally only in the latter. Note that ATM machines only dispense EC dollars.

Major credit cards such as Visa, American Express and MasterCard are widely accepted for payment. The island's Royal Bank of Canada ATM s accept Cirrus and Plus cards, as well as Visa and MasterCard. Cash machines are located on William Peter Boulevard in Castries, at the Rodney Bay Marina, and on New Dock Road in Vieux Fort. The Caribbean Banking Corporation ATMs at Micoud Street in downtown Castries and Gablewoods Mall, north of town, take the same cards. US dollar travellers' cheques are accepted by many businesses, but it's wise to always carry some cash with you, as taxi drivers, market stalls and many smaller restaurants or guesthouses won't accept credit cards or travellers' cheques.

Banks hours are Monday to Thursday 8am-3pm, and Friday 8am-5pm. The National Commercial Bank exchange bureau at Hewanorra airport in Vieux Fort has extended hours (Mon & Tues 12.30-9pm, Wed 4.30-9pm, Thurs 2-9pm, Fri 12.30-9pm, Sat 2.30-9pm, Sun 1-9pm), and the Royal Bank of Canada branch at the Rodney Bay Marina is open 8am-noon each Saturday. Banks always offer the most favourable exchange rate .