Making purchases while traveling in Ireland is relatively easy. Cash is the most immediate form of payment and accepted everywhere, but major credit cards are also widely accepted. The only hiccup with cash is to be aware of what currency you're using, since the island of Ireland is made up of two different countries: the Republic of Ireland, which uses the euro, and Northern Ireland, which is part of the UK and uses pound sterling. The good news is that, in the border regions, both currencies tend to be accepted, but this should never be taken for granted.
Overall, using cash or plastic in Ireland should cause no problems, but it's always important to brush up on your knowledge of local money and the methods of monetary transactions available when traveling overseas. A little preparation will prevent you from making any simple mistakes with your cash.
Euros and Cents
One euro has 100 cents and coins are available in denominations of 1, 2, and 5 cents (all copper); 10, 20, and 50 cents (all golden); and 1 and 2 euros (silver with gold). While the design of the side bearing the numerals is standardized throughout the eurozone, the reverse is of local design—in Ireland, you will find a design with an Irish harp.
Non-Irish euro coins are legal tender, but take note that some machines will only accept non-Irish euro coins with a bit of persuasion (try, try again) or not at all. Spanish coins are notoriously tricky and can be a headache on automated toll booths on the motorways.
Banknotes are totally standardized throughout the eurozone and most commonly available in denominations of 5, 10, 20, and 50. Higher denominations (100, 200, and even 500 euros) are available, but rare, and some traders may refuse them.
In Ireland, a “rounding system” was introduced in 2015, so that the total of a transaction will generally be rounded (up or down) to the nearest five euro cents. So if your coffee (or Guinness) comes out to 4 euros and 22 cents, you'll only pay 4 euros and 20 cents. But if the price comes out to 4 euros and 23 cents, you'll pay 4 euros and 25 cents.
In the long run, you won’t be off any better or worse than before.
Pounds and Pennies
Here are the most important facts you need to know about the pound used in Northern Ireland.
One pound has 100 pence, and coins are available in denominations of 1 and 2 pence (all copper); 5, 10, 20, and 50 pence (all silver); 1 pound sterling (golden); and 2 pounds (silver with gold). The 50 pence and 1 pound coins can have commemorative or local designs on the reverse.
Banknotes are commonly available in denominations of 5, 10, and 20 pounds. The higher denomination 50-pound notes are available, but rare, and some traders may refuse them.
Banknotes in the United Kingdom are issued by individual banks rather than by a central authority, and you will find that each bank uses its own design. Apart from notes issued by the Bank of England, you will encounter notes from Northern Irish banks and the Bank of Ireland, plus you may also receive Scottish notes as change. All are valid currency but the different designs can be confusing. In addition, Northern Bank is now part of Danske Bank, which is issuing pounds sterling with a Danish company name. All of this will really only cause problems for you if you have a lot of leftover cash when you head home. Notes not issued by the Bank of England may be harder to exchange back in your home country, so spend them first.
Rounding to the nearest five cents as with the euros is not the practice in Northern Ireland.
Many shops in the border counties are flexible with currency and accept the foreign Irish currency at their own (sometimes quite favorable) exchange rate. You will, however, only receive change in the local currency. The only other place where you will find some flexibility in currency is at the odd parking meter that will accept euros in Northern Ireland.
Plastic Is Fantastic
Credit cards are widely accepted everywhere in both the Republic of Ireland and Northern Ireland, with Visa and Mastercard being the most popular. Acceptance of American Express and Diners cards is decidedly lower and JCB cards are nearly unknown. As in the US, there might also be a minimum purchase clause in many shops—for example, no credit card transactions below 10 euros or even 20 pounds—and beware of the trader charging you in your own currency "for convenience." Insist on being billed in pounds or euros when purchasing goods, not in dollars. When charging you in your own currency, the merchant uses their own exchange rate which will more than likely leave you paying extra.
Debit cards are also widely accepted, but you should also check with your card provider for information on fees before traveling. In Ireland, the "cashback" feature when making purchases is possible in some stores. Most ATMs (colloquially called "Hole in the Wall" or simply cash machines) will also accept credit cards for cash withdrawal, but check the fees for cash advances and foreign transactions with your credit card company first. Credit card skimming is on the decline, but still a risk. So watch out for any contraptions at ATMs that look suspicious.
In Northern Ireland, only credit cards using the "chip and PIN" system are accepted in shops.
Personal and Traveler's Checks
Traveler's Checks used to be a secure and convenient alternative to cash and credit cards but even historically were not actually accepted outside the major tourist centers. Most traders will not accept them anymore and you will even have problems exchanging them in most banks.
Personal checks are, generally speaking, not accepted at all, especially not those from non-Irish banks.