Most Irish banks will not accept U.S. $100 bills. Many Irish financial institutions have recently stopped accepting or cashing traveler’s checks. Credit cards are widely accepted throughout Ireland. ATMs are widely available, but some, particularly in rural areas, may not accept debit cards from U.S. banks.
Some airlines have advised their passengers that their passport must remain valid for six months after their entry into Ireland; however, the Government of Ireland states that this is a recommendation of the airline industry and is not an Irish legal requirement. Travelers must be in possession of a valid passport to enter Ireland.