General information only, not legal advice. Facts checked October 2026.
Millions of people around the world carry Irish roots. If one of your grandparents — or a parent — was born in Ireland, you may have a legal right to Irish citizenship. This guide sets out who qualifies, what documents you need, what you will pay, and how long the process takes.
Irish citizenship by descent is recognised under Irish law. It is not automatic in every case, but for many people with Irish ancestry, the right is real and worth pursuing. An Irish passport gives you the right to live and work anywhere in the European Union. It is also a formal, legal connection to the country your family came from — something many in the diaspora find deeply meaningful.
The Two Main Routes to Citizenship by Descent
There are two main ways to claim Irish citizenship through ancestry.
Route 1: Through a Parent
If one of your parents was an Irish citizen at the time you were born, you are automatically an Irish citizen from birth — regardless of where you were born. You do not need to do anything to acquire the citizenship itself, though you will need to apply for an Irish passport to travel on it.
Your parent may have become an Irish citizen in several ways: by being born in Ireland, or by having previously registered on the Foreign Births Register (explained below). The key point is that your parent must have been an Irish citizen at the time of your birth, not simply at some later date.
Route 2: Through a Grandparent
If a grandparent was born on the island of Ireland — which includes Northern Ireland as well as the Republic — you have the right to apply for Irish citizenship through the Foreign Births Register.
This is the most commonly used route for the Irish diaspora worldwide. You do not need to have visited Ireland. You do not need to speak Irish or Gaeilge. You do not need to be able to trace your family back further than one generation. The right comes from the fact of your grandparent’s birth on the island.
It does not matter which county your grandparent came from, when they emigrated, or how long they lived elsewhere afterwards. For a deeper walkthrough of this specific route, see our guide to claiming an Irish passport through a grandparent.
What Is the Foreign Births Register?
The Foreign Births Register (FBR) is an official database kept by the Irish Department of Foreign Affairs. Registering on it is how you formally establish your Irish citizenship when you are claiming through a grandparent born in Ireland.
Registration does not create your citizenship — Irish law holds that you already have the right to citizenship by virtue of your grandparent’s birth. What registration does is formally record that citizenship so you can obtain an Irish passport and pass the right on to any children you may have in the future.
That last point deserves emphasis: if you plan to pass Irish citizenship on to your own children, you must register on the Foreign Births Register before those children are born.
Citizenship does not pass automatically to a third generation born abroad unless the intervening generation — your parent — had already registered their citizenship before you were born. If your parent was born outside Ireland and never registered, and was not otherwise an Irish citizen at the time of your birth, then you will need to claim through the grandparent route yourself. Once you register, your own future children born outside Ireland can in turn claim through you — provided you register first.
This is why acting sooner rather than later matters. The right does not expire, but the chain can be broken by inaction.
What Documents Do You Need?
The documents required depend on which route you are using. For the grandparent route via the Foreign Births Register, you will generally need:
- Your own full birth certificate
- Your parent’s full birth certificate
- Your grandparent’s full birth certificate, showing they were born on the island of Ireland
- All marriage certificates that link the generations together (for example, your grandparents’ marriage certificate, and your parents’ marriage certificate if your parent was born under a married name)
- Proof of your grandparent’s Irish nationality at birth, where required
All documents must be originals or certified copies. Documents not in English will need a certified translation. Civil registration records for births, deaths, and marriages in Ireland are held by the General Register Office, and many records are searchable online at irishgenealogy.ie, which can help if you need to obtain Irish certificates. See our complete guide to Irish civil registration records for how to locate and read them.
If records are unavailable — for example, if a birth was never formally registered, which was not uncommon in rural Ireland in the early twentieth century — you may be able to support your application with other evidence such as census records, church baptism records, or school records. This adds complexity but is not automatically disqualifying.
For the parent route, the document requirements are similar, focused on proving your parent’s Irish citizenship and your own birth.
What Does It Cost?
As of October 2026, the fee for registering on the Foreign Births Register is €278 per application. This is the fee paid to the Irish government; it does not include the cost of gathering documents.
You should also budget for:
- Certified copies of birth and marriage certificates from Ireland and your home country — typically a few pounds or euros each, but the total can add up
- Postage and document handling
- Certified translation fees if any documents are not in English
Once your citizenship is registered, you can apply for an Irish passport. As of October 2026, fees are approximately €75 for a standard 32-page passport booklet, €105 for a larger 66-page booklet, and €35 for a passport card. Fees are set by the Irish government and may change; check the Department of Foreign Affairs website (dfa.ie) for current rates before applying.
Some people use a solicitor or a heritage specialist to help with their FBR application, particularly if family records are incomplete or names were changed across generations. Professional fees vary widely. Many applicants do complete the process without professional help, but if your situation is complicated, expert guidance can prevent expensive delays.
How Long Does It Take?
Processing times for the Foreign Births Register have been lengthy. Demand surged significantly after 2020 as many people in Britain with Irish grandparents applied to retain access to EU citizenship and travel rights following the United Kingdom’s departure from the European Union.
Waiting times blew out to two years or more during the post-Brexit surge in applications in the early 2020s, but have since improved substantially — official figures put standard processing at roughly 9 to 12 months from receipt of supporting documents in the most recent published figures. Applications missing documents take longer. There is no premium service or way to pay to speed up an FBR application — the best thing you can do is submit a complete, accurate application the first time, so you do not lose additional time responding to requests for further documents, and check the current estimate on dfa.ie before you apply.
Passport processing, once citizenship is established, is much faster — typically a matter of weeks for a standard application submitted online through the Passport Online service.
Common Questions
Does the right to citizenship by descent expire?
No. If you qualify, the right does not lapse because of the passage of time. A birth certificate from the 1920s is just as valid as one from last year. However, as noted above, the right must be registered in each generation before children are born for it to pass forward.
Does it matter which county in Ireland my grandparent came from?
No. The right applies to people born anywhere on the island of Ireland — north or south, any county, any town or townland.
Can I hold dual citizenship?
Irish law permits its citizens to hold multiple citizenships. Whether your home country allows dual nationality is a separate matter governed by that country’s own laws. Many countries — including the United States, Canada, Australia, and the United Kingdom — do permit it, but you should check your own country’s rules if you are unsure.
My grandparent emigrated as a child. Do they still count?
Yes. What matters is that your grandparent was born on the island of Ireland. Where they lived after emigrating has no bearing on your claim.
What if my grandparent was born out of wedlock?
You may still be able to claim, but the documentation requirements can be more complex. The Irish Nationality and Citizenship Act has provisions for these situations, but it is worth seeking specific advice from the Department of Foreign Affairs or a qualified solicitor.
What about great-grandparents?
There is no direct route to Irish citizenship through a great-grandparent alone. However, if your great-grandparent was Irish, and your grandparent registered on the Foreign Births Register before your parent was born, then your parent may be an Irish citizen — and you could qualify through the parent route. The citizenship chain, if registered in each generation, can carry forward.
How to Start Your Application
The application form for the Foreign Births Register is available on the Department of Foreign Affairs website at dfa.ie. The site includes checklists for different family circumstances and a list of Irish embassies and consulates worldwide.
- If you live outside Ireland: Apply through the Irish embassy or consulate covering your area.
- If you live in Ireland: Apply directly to the Department of Foreign Affairs, Passport Service, in Dublin.
Begin by gathering your documents. Start with your grandparent’s birth certificate — if you do not have it, the General Register Office and irishgenealogy.ie are the first places to look. Work backwards and forwards from there to build a complete chain of documentation.
Take care to read the current requirements on the official government website before you begin, as procedures and fees are subject to change.
This article provides general information only and does not constitute legal advice. Eligibility for Irish citizenship depends on individual circumstances. Always verify current requirements and fees directly with the Irish Department of Foreign Affairs. Facts checked October 2026.
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