Since the fast-inflating sucre was replaced by the US Dollar in the year 2000, currency has become a much easier issue for foreigners in Ecuador.  All notes are US currency, while US and Ecuadorian coins can be used interchangeably (the Ecuadorian coins are in the same denominations and sizes as their US counterparts).  Euros can be changed at a few places, pounds less so; it’s best to stock up on dollars in your home country if you’re from outside the US.  Travelers checks can be cashed at  just a few banks, but are hard to cash outside of the major cities and even within Quito itself (and prepare yourself for lines at the bank).  American Express is the most widely-accepted brand. You are better relying on ATMs which are readily available in Quito.

While many ATMs are affiliated with international networks, be forewarned that service can be sporadic.  Despite logos, your card may be rejected for no apparent reason.  Don’t despair, and try two or three times at an ATM before moving to another bank.  Small towns often have zero to one ATMs, and that one may or may not work, so be sure to stock up on cold hard cash in the larger towns, and use a moneybelt or pouch to foil would-be pickpockets.  Theft at ATMs is a common event, so always be aware of your surroundings when making a withdrawal.

There was a rash of counterfeit $100 bills in 2005 and most businesses refused them at that point, but the bills were still acceptable at banks.  Bills of $20 and smaller are best, also because change is a precious commodity in Ecuador. 

Credit cards are fairly widely accepted, particularly Visa, MasterCard and Diners (American Express less so).  Be forewarned that a logo on the restaurant window does not mean that they will accept the credit card “at the moment,” so be sure to doublecheck if you are relying on paying with plastic.  Surcharges may also apply when credit cards are used, or discounts offered for payment in cash. 

In a pinch, Western Union has offices throughout Ecuador; significant fees apply.