The currency for the Republic of Ireland is the Euro and for Northern Ireland is the Pound Sterling. Proper currency is required when traveling between the Republic and Northern Ireland.
You can exchange your current money for Euro or Pounds at the airports, Ireland banks and local ATM machines. While the Dublin area is reasonably well served with ATMs, the same can't be said for smaller towns and villages where there may be at most one ATM in the locality.
Acceptance of Visa and MasterCard is almost universal for retailing and most services, including supermarkets, accommodation, railways, restaurants, gas stations, department stores, payment of parking tickets, airport parking charges, etc. American Express and Diners Club cards are also accepted by some service establishments. Very few if any establishments accept the Discover Card.
Currency Convertor: Click here to get current exchange rates for your country.