Born outside Ireland?
Foreign Birth Registration - Guidelines for Applicants Resident in Great Britain
You are automatically an Irish citizen if one of your parents was an Irish citizen who was born in Ireland.
You can become an Irish citizen if one of your grandparents was born in Ireland, or you can become an Irish citizen if one of your parents was an Irish citizen at the time of your birth, but was not born in Ireland. If you're eligible, you can register your birth on the Foreign Births Register.
Information on Foreign Birth Registration Fees are available on this page at Tab 5 (headed Fees).
Getting a replacement FBR certificate
Find out more if you’re already an Irish citizen through Foreign Births Registration, but you need to apply for a replacement certificate.