Irish citizenship through your grandparents: how the Foreign Births Register works

If one of your grandparents was born in Ireland, you can probably become an Irish citizen, but only once your name is on the Foreign Births Register.

The short version

• Irish-born grandparent? You qualify. So do people whose parent was an Irish citizen when they were born, even if that parent wasn't born in Ireland [1].
• If your parent was born in Ireland, skip the register. You're already Irish and can apply straight for a passport [1].
• Fees in 2026: €278 (about USD 310) for adults and €153 (about USD 171) for under-18s, including the €8 postage and handling fee [1].
• The wait: applications are handled in strict date order, and the Department of Foreign Affairs said it was taking about 12 months [1].
• You're a citizen from the date of registration, not from birth. That matters for your own kids [1].

USD conversions in this guide use the Federal Reserve H.10 rate of October 30, 2026 (EUR 1 = USD 1.1163).

Who qualifies

Millions of Americans claim Irish roots on St. Patrick's Day, but the law draws a clear line. The Department of Foreign Affairs (DFA) sets it out like this [1]:

The DFA uses the phrase "the island of Ireland" for parents, which covers Northern Ireland too. If your grandparent was born in Belfast or Derry, ask the DFA's customer service hub to confirm how your case is treated before you pay.

The timing trap for the next generation

Here's the fine print that trips families up. The DFA says that if an expectant parent isn't already on the register when the child is born, that child isn't entitled to Irish citizenship [1]. In other words, if you register after your kids are born, they can't claim through you. If you're planning a family, register first. The DFA lets expectant parents who might not make it in time contact its Foreign Birth Registration Customer Service Hub [1].

The documents you'll need

The checklist for an adult applying through an Irish-born grandparent has three parts, and the DFA wants originals unless it says otherwise [1]:

About you - The completed, signed and witnessed application form - Your original civil birth certificate showing your parents' details (the long form, not a hospital certificate) - Your original civil marriage certificate or other name-change document, if your name changed - A photocopy of your current government photo ID, such as a US passport or driver's license, certified by your witness - Two separate original proofs of address - Four color photos, two of them signed by your witness

About your parent (the link generation) - Their original civil birth certificate showing their parents' details - Their civil marriage certificate or name-change document, if relevant - A certified copy of their current photo ID, or their original civil death certificate

About your Irish-born grandparent - Their original civil birth certificate showing their parents' details - Their civil marriage certificate or name-change document, if relevant - A certified copy of their photo ID, or their original civil death certificate

Most American applicants end up ordering certified copies from county vital records offices back home, plus the grandparent's Irish birth record. Tracking down a 1920s birth certificate from a small Irish parish can take months, so start there.

Who can be your witness

Your witness has to know you personally, can't be a relative, and has to be currently practicing in their profession [1]. The DFA's list includes police officers, teachers and school principals, clergy, doctors, nurses, pharmacists, dentists, lawyers, notaries, bank managers, accountants, elected officials, vets and chartered engineers [1]. The same witness signs the form, two photos, and certifies the copy of your ID, and uses an official stamp or adds a business card [1]. A notary at your local bank branch stateside is often the easiest choice.

How to apply, step by step

1. Check the line. Make sure the Irish-born person is your grandparent (or that your parent was already a citizen when you were born).
2. Gather the civil records for all three generations. Name differences across documents (a maiden name, an anglicized spelling) need marriage or name-change records to bridge them.
3. Start the online application on the DFA's Foreign Birth Registration site and pay online [1].
4. Print, sign and get it witnessed, along with the photos and ID copy.
5. Mail the original documents as the online system tells you. Use tracked mail.
6. Wait. Applications are processed in date order, about 12 months when we checked [1]. Incomplete applications are sent back unprocessed [1], which puts you at the back of the line.
7. Get your certificate. Once you're entered on the register, you're an Irish citizen and can apply for a passport [1].

Fees and timelines in 2026

Registration fees are from the DFA's FBR page [1] and passport fees from its passport fees page [2]. The postage and handling part of the FBR fee isn't refundable [1].

After registration: your Irish passport

Your FBR certificate is your proof of citizenship. With it you can apply for an Irish passport through Passport Online, which the DFA calls the quickest and cheapest way to apply [2]. Irish citizens living in eligible countries can apply for first passports online at the standard fees [2]. You can also add a Passport Card for €35 [2], a wallet-sized card version of your passport.

Once you're registered and living in Ireland, your FBR certificate also counts as identity for a PPS number, as long as you pair it with an Irish or UK driver's license or learner permit, or you use your new Irish passport [3].

What it means for an American

Becoming Irish doesn't end your US citizenship. You'll be a dual national, and a few things follow from that:

• Enter and leave the US on your US passport. Use the Irish one for Ireland and the EU.
• You can live and work in Ireland and across the EU without any of the work permits or immigration registration that other Americans need. That alone is the reason many people apply.
• Uncle Sam still taxes you. Irish citizenship doesn't change US citizenship-based taxation. US citizens are taxed on worldwide income wherever they live [4].
• Your kids. A child you have after registration is Irish through you [1]. Their US citizenship goes through a CRBA if they're born abroad.

A US expat tax preparer can check how a move to Ireland affects your US return, and the Irish citizenship side is worth a chat with the DFA's customer service hub if your family history is messy. People who've been through it are a great resource too, and our community group for Americans in Ireland has plenty of them comparing notes on parish records and wait times.

Sources

1. Department of Foreign Affairs: Registering a foreign birth
2. Department of Foreign Affairs: Passport fees
3. Citizens Information: Personal Public Service (PPS) number
4. IRS: US citizens and resident aliens abroad

Keep reading

• Moving to Dublin as an American: visa routes
• Getting a PPS number in Dublin
• Dual citizenship and US law
• Registering a child born abroad: the CRBA