HI, Sorry that i can'd confirm, but AMEX isn't widely accepted in Ireland so you may want to contact the restaurant. Also, if you do pay with credit cards be sure to pay in your local currency, if restaurants perform the exchange for you the rate can be 10% more. My experience is with US dollars and have traveled to Ireland a few times in the past 4 years. Even taking cash at ATM's is a much better rate, i recently was charged 1.10 US per Euro which is great. Enjoy the chophouse!
You could also ask when calling for a reservation if you make one.
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