The currency in Zante is the Euro, which is also used across the whole of Greece. You’ll find ATM machines across the island, although these are most common in resort locations and towns. Be aware that some banks may charge you for using your credit or debit card abroad, so it’s highly recommended to buy your travel money in advance.
If you’re in need of Zante currency, you’ll find Foreign Exchange facilities in most resorts and towns; look out for those offering the most competitive rates. Avoid buying your currency at the airport if possible, as you’ll usually end up paying more for the convenience.