How to Become an Irish Citizen
Genealogy 101: Irish Jus Sanguinis
It’s March and that means St. Patrick’s Day is upon us, which may have you wondering about your Irish Heritage.
You’ve always known there was a bit of the Emerald Isle in your blood. Maybe it was a grandmother with a lilting accent, a great-grandfather who came over during the Famine, or a family surname that has been spoken about at every family gathering with an air of reverence because it was Irish. From time to time, you’ve considered, “Wouldn’t it be wonderful to reclaim your ancestral roots and become an Irish Citizen?”
Well, I have good news: that dream and your heritage might be worth more than just a fun fact at the dinner table. Ireland allows people born outside the country to claim citizenship through their ancestry, and the process—while document-heavy—is more accessible than you might think.
This is known as jus sanguinis, which is Latin for “Right of Blood.”
And, since we’re all family historians here—there is also a good chance you have, or at least know where to find, all the documents you need to obtain your dual citizenship.
According to the Nomad Passport Index, the Irish passport ranked first overall as the strongest passport to obtain in 2025. That means:
Visa-free or visa-on-arrival access to over 180 countries,
the right to live and work anywhere in the EU, and
access to UK universities and healthcare through the Common Travel Area.
It’s no wonder interest in Irish citizenship by descent is surging. (And it is, so let’s keep that in mind as you read on.)
I put this guide together to help walk you through everything you need to know about the process of obtaining Dual Citizenship in Ireland, from figuring out if you’re eligible to submitting your application.
Step 1: Determine If You’re Eligible
This is the most important step—and where genealogy research becomes essential. Irish citizenship by descent works differently depending on which generation of your family was Irish.
There are three main eligibility tiers based on ancestry: an Irish-born parent, an Irish-born grandparent, or in some limited cases, an Irish-born great-grandparent.
Here’s how each tier works:
If one or both of your parents were born in Ireland: You automatically qualify as an Irish citizen by descent—this is considered a birthright. You don’t need to register on the Foreign Births Register; you can apply directly for an Irish passport. But, there is a date that you need to be aware of in this regard. If you were born on or after January 1, 2005 and you have a child who was born outside of Ireland, their status will depend on your citizenship status at the time of their birth.
If one of your grandparents was born in Ireland: You can become an Irish citizen by registering on the Foreign Births Register. This is the classic “grandparent rule” that many people with Irish heritage use to connect with their ancestral citizenship. Having an Irish grandparent doesn’t make you a citizen automatically—you must go through the registration process. That process includes a strong documentation thread, which means you will need to document birth, marriage, and death records to show a direct path from you to your Irish Grandparent. To learn more about the process—head here.
If your connection is through a great-grandparent: Your eligibility depends on whether your parent registered with the Foreign Births Register before you were born. If they did, you may still qualify by becoming a naturalized citizen. This registration is a crucial, and often-missed, detail—the timing of your parent’s registration matters enormously. To learn more about becoming a naturalized Irish citizen—head here.
Important boundary to know: Unless at least one parent or an Irish-born grandparent was an Irish citizen at the time of your birth, you have no automatic right to Irish citizenship on the basis of extended previous ancestry. You also cannot claim citizenship on the basis of a cousin, aunt, or uncle who was an Irish citizen.
Step 2: Start Your Genealogy Research
Before you fill out a single form, you need to build a paper trail connecting you to your Irish ancestor. This is where the genealogy work begins. I cannot express how important this step is. Do not schedule an appointment with the Irish Consulate until you have every document needed. If you are not sure what documents you need. Luckily, Ireland.ie is a wonderful resource that lists every document you need to find (and what type of document) prior to filling out those forms.
What you’re trying to establish: You need to create an unbroken documentary chain from yourself back to the Irish-born ancestor (parent or grandparent) through whom you’re claiming citizenship. Every link in that chain needs supporting documents.
Where to look for records:
Ancestry.com, FamilySearch.org, and Findmypast.ie — These are your starting points for digitized Irish records including census data, birth registrations, and emigration records. NOTE: The documents you find on these sites are NOT the documents they will want. The consulate will require CERTIFIED copies, but using these sites to locate where they are being held and that they exist is a great place to start.
The General Register Office of Ireland (GRO) — Holds civil registration records for births, marriages, and deaths in Ireland from 1864 onward. You can order certified copies directly. The GRO has all types of vital records neatly laid out, making it easy to navigate, and even a link to contact them directly. (Saving you time searching for a “contact” or “help me!” link)
IrishGenealogy.ie — Ireland’s official free genealogy portal, with church records dating back to the 1600s for some parishes. Best part, this is a no-cost resource.
The National Archives of Ireland — Contains census records, Griffith’s Valuation (a mid-1800s property survey), and estate records useful for locating ancestral townlands. This will come in handy if you are not sure exactly where in Ireland your ancestors lived. Once you learn that information, you will be able to begin the search for vital records in that area. The National Archives also offer help with research and learning opportunities.
Ellis Island and Ancestry ship records — If your ancestor emigrated to the US, ship manifests often include their county or town of origin in Ireland. Please know that you can also order a certified copy of the ship passenger list from the National Archives (USA).
Step 3: Gather Your Official Documents
Once your research has mapped out the family tree, you need to collect official, certified documents—not photocopies, not screenshots of Ancestry records. (As stated above and again below)
Only originals or certified true copies issued by government agencies are accepted; regular copies will not suffice.
Here is what you will typically need:
Your own full birth certificate (long form, not the short version)1
Your parents’ birth and marriage certificates
Your grandparents’ birth and marriage certificates (the Irish-born grandparent’s Irish birth certificate is critical)
Death certificates for any deceased ancestors in the chain. (these should also be long from)
If your Irish ancestor’s records are incomplete, damaged, or were lost (as many were in the 1922 Four Courts fire that destroyed much of Ireland’s Public Record Office), a professional genealogist with Irish record expertise may be able to help reconstruct the lineage using alternative sources like church baptismal records, land valuations, or newspaper archives.
To find a genealogist in Ireland for dual citizenship, search directories like Accredited Genealogists Ireland (AGI), the Association of Professional Genealogists (APG), or specialized services like Timeline.ie, Ancestor Solutions, and Oak Ancestry.
Key experts such as Genealogy.ie and Irish Research Specialists can help secure necessary birth/marriage records for Foreign Birth Registration.2
Step 4: Register on the Foreign Births Register
For most people claiming through a grandparent (or a great-grandparent whose child registered before you were born), the pathway to citizenship runs through the Foreign Births Register (FBR), maintained by Ireland’s Department of Foreign Affairs.
Persons born outside of Ireland who have an Irish national grandparent born in Ireland may obtain Irish citizenship through registration in the Foreign Births Register.
Here’s how the process works:
Start your application online at the Department of Foreign Affairs website (dfa.ie). Create an account and complete the online application form.
Upload your supporting documents — scanned copies of all the certified birth, marriage, and death certificates in your chain.
Submit your physical application — after completing the online portion, you will print, sign, and mail the application along with your original documents to the appropriate consulate or Irish embassy for your region.
Pay the application fee — currently €2783 for a Foreign Births Register application.
Wait for processing — the process for acquiring Irish citizenship based on foreign birth registration currently takes nine months but may take up to 24 months.
Receive your Foreign Birth Registration certificate — this is your proof of Irish citizenship and allows you to apply for an Irish passport.
Step 5: Apply for Your Irish Passport
Once your Foreign Birth Registration is confirmed, you are officially an Irish citizen. The final step is applying for your passport through the Passport Online system at passportsonline.dfa.ie.
You will need:
Your Foreign Birth Registration certificate
Two passport photos
Passport application fee (currently €75 for a standard 10-year passport)
Your Irish passport is your gateway to everything dual citizenship offers.
What Dual Citizenship Actually Gets You
Ireland allows dual citizenship, which means you can become an Irish citizen and remain a citizen of another country. (Always verify your home country’s rules on dual citizenship, as some countries do not permit it.)
As an Irish citizen, you gain:
EU freedom of movement — the right to live, work, and study in any of the 27 EU member states. Here is a list
UK access — through the Common Travel Area, Irish citizens can live and work in the United Kingdom
One of the world’s strongest passports — visa-free or visa-on-arrival to over 180 countries
Education benefits — access to Irish and EU universities at domestic tuition rates rather than international student fees
The ability to pass citizenship on — you can then pass your citizenship on to your minor and future children, securing the Irish heritage line for future generations
A Few Common Pitfalls to Avoid
Don’t assume you qualify based on a famous Irish surname alone. Eligibility is strictly about documented, direct lineage—not cultural identity or family lore. As the saying goes, the proof is in the pudding. No proof. No pudding for you.
Don’t wait if you’re close to the great-grandparent threshold. If your parent is still living and eligible to register through a great-grandparent, they should consider registering before you apply, as it opens the door for you.
Don’t submit uncertified copies. Applications are rejected for documentation issues regularly. Order official certified copies from the issuing government authority in the relevant country. If you try to trick them, you will not win. All documents required must be certified. This can get costly, so price things and buy them as you can. Once you have all your copies, proceed.
Don’t expect a quick turnaround. Processing times can stretch to two years. Apply early and be patient.
In the end…
Claiming Irish citizenship through ancestry can be very meaningful aspect of learning about genealogy and family history. You are not just building a family tree, you’re activating a “right of blood,” aka a legal birthright, that connects you to your heritage in a concrete way.
Remember, your ancestors most likely came here due to circumstances out of their control. Like, the Great Potato famine, oppression, and economic conditions which drove them out of their home country to the United States (or wherever they ended up). Now, with your dual citizenship process, you have the chance to lead the family back home.
Whatever their reason was to leave Ireland, their story is part of your story. And with the right documents in hand, their story can head back once-they-came, through you.
Start with what you know, dig into the records, and let the paper trail lead you home. Need help? Send me a message.
To learn more, visit me at GenealogyByAryn.com.
Long-form birth certificates are comprehensive copies of the original record, featuring details like birth hospital, time, and parents’ residence, required for passports, immigration, and international uses. Short-form certificates (abstracts) list only basic info—name, date, place, and parentage—and are usually sufficient for domestic needs like school or driver’s licenses
You may need to hire a genealogist in both Ireland and in the United States depending on which documents you are searching for.
That’s $322.86 at the time I posted this. Check current currency rates before you begin this process.
I applied in June 2025. I check my email everyday now as I should be receiving notice soon. It was definitely an ordeal to gather all the verified documents (Took me about 6 months). Praying that they don’t ask for additional documents. If all goes well, I should have my Irish passport by July. Planning to move abroad in October.
I hadn’t heard this Aryn. It’s very interesting and I have no doubt there will be many who apply