The currency on Trinidad and Tobago is the Trinidad and Tobago dollar, also known as the TT pronounced teetee. US dollars are also widely accepted. Visa and Mastercard credit cards are accepted at many stores. American Express, Diners' Club, Discover, JCB and others are only accepted in a few places. ATM ABM cards using Cirrus and Plus networks will work in local ATMs and will allow you to make withdrawals in TT dollars converted to your home currency. The exchange rate when withdrawing from the ATM is slightly better than when exchanging cash. There are also ATMs in a few places such as shopping malls that will dispense US dollars. Be advised that Trinidad and Tobago ATMs do not accept PINs longer than four digits. Consider changing it to four digits before you travel. As of December 2011, Republic Bank ATMs Blue Machines accept six-digit PINs.
Prices in shops and stores are generally displayed and do not change according to the customer. Outdoor vendors, however, are another story: they are likely to charge a different, higher price for a foreigner than for a local. A few will even suggest or demand payment in US dollars. You can try haggling, or just grin and bear it.
Most items except necessities and certain other items that are zero rated attract Value Added Tax VAT at the rate of 15%. The tax is collected at the time of sale.
Weights and measures are officially in Metric, however it is not uncommon for imperial English units to still be used. Though the other units are the same, the imperial gallon is not the same as the U.S. gallon.