Citizenship by descent through a grandparent
You can claim citizenship through a grandparent in several countries, each on its own terms. Ireland registers anyone with a grandparent born on the island of Ireland in its Foreign Births Register. Germany and Poland pass citizenship down more than one generation when no one in the line lost it first. Canada, since 15 December 2025, reaches beyond the first generation born abroad. Italy, since Law 74/2025, only through a grandparent who held Italian citizenship alone. The proof is always a chain of documents: a birth certificate for each link, marriage or name change records where names changed, and proof of the grandparent's citizenship. You can map that chain free in your cases.
Which countries allow it, and on what condition
The routes Rootdossier organises, as their sources stated them when we last read them on 28 September 2026. Each row links to the country page, where every rule is listed with its source.
| Country | Route | Condition in brief |
|---|---|---|
| Ireland | Foreign Births Register | A grandparent born on the island of Ireland. You become Irish on the day you are entered in the register, not from birth. |
| Germany | Ordinary descent, or the section 5 declaration | Each parent in the line was German at the child's birth and did not lose it first; or the old rules on mothers and fathers left a parent out. |
| Poland | Confirmation of citizenship | Citizenship passed down without a loss, for example by a foreign naturalisation before the next birth. |
| Canada | Descent beyond the first generation | Automatic for people born abroad before 15 December 2025; later births depend on the parent's time in Canada. |
| Italy | Only-Italian grandparent (narrowed) | The grandparent held Italian citizenship alone. Great-grandparent lines no longer qualify on this route. |
The paperwork is about three people
A grandparent claim links three people: you, the parent through whom the line runs, and the grandparent. Each link needs a record that names both sides: your birth certificate naming your parent, and your parent's birth certificate naming the grandparent. Where a name changed, usually at marriage, the marriage certificate or a name change record joins the two names.
Then comes proof of the grandparent's own status: an Irish civil birth record, an old German passport or citizenship card, a Polish identity document or civil record, a Canadian birth or citizenship certificate, an Italian birth record plus proof the person never took another citizenship. Some routes add papers about you alone, such as a police certificate for the German declaration or proofs of address and photographs for the Irish register.
How a line breaks
- A naturalisation abroad before the next child was born. For Poland and for ordinary German descent, a grandparent who took another citizenship before your parent's birth may have ended the line.
- A generation limit. Italy now stops at the grandparent on its main route. Ireland's register stops at the grandparent too: a great-grandchild can register only through a parent who was entered in the register before the great-grandchild was born.
- A date cut-off. Canada treats births before and after 15 December 2025 differently.
- A missing record. Where a civil record never existed, a baptismal record may stand in: Ireland accepts one for grandparents born before 1864.
Worked example: an Irish grandmother
In the invented Irish sample, Maeve claims through her grandmother Bridget, born in Queenstown in 1931. The register lists 11 documents: five for Maeve, three for her father and three for Bridget. The discrepancy check compares what each of Bridget's documents says and finds 9 mismatches: three on her name, three on her birth date and three on her birth place.
Two of those explain themselves. "Queenstown, County Cork" and "Cobh, Ireland" are the same town, renamed. The birth date reads 2 November 1931 on one record and 11 February 1931 on the other: the day and month were swapped. The rest need a note on how they were settled before filing. Open the sample from your cases to see it.
Common mistakes
- Ordering short-form birth certificates. Most routes want the long form that names the parents, because that is what links one generation to the next.
- Starting with the grandparent. Start with yourself: your own records are the quickest to get, and they tell you exactly what names to search for further back.
- Ignoring a naturalisation date. For Poland and ordinary German descent, when a grandparent naturalised abroad matters as much as whether they did.
- Assuming a great-grandparent counts. Ireland's register and Italy's narrowed route stop at the grandparent; in Ireland a child born before the parent was registered is not entitled through that parent.
- Treating a guide as the rule. Rules change; read the current official page before you order documents, and ask the consulate or a lawyer when the case is unusual.
Start your dossier
Pick your country and route, add the people in your line, and the register lists every document the route asks for, with the rule behind each one. Free for one case. Your family's records stay in this browser.
Frequently asked questions
Can I get citizenship through a great-grandparent?
Sometimes. Germany, Poland and Canada can reach further back when the line was never broken, but Ireland's Foreign Births Register and Italy's main route after Law 74/2025 stop at the grandparent. In Ireland the one way further down is through a parent who was entered in the register before you were born.
Do I need my parent's documents if my parent is not applying?
Yes. Your parent is the link between you and the grandparent, so their birth record, and their marriage or name change record where a name changed, are part of your file on every route.
Is Rootdossier a citizenship service?
No. It organises your own paperwork: the chain, the documents each route lists, their status, costs and mismatches. It does not decide eligibility or file anything. Confirm your route with the consulate or a lawyer.
Sources
Last reviewed 28 September 2026 against:
- Registering a foreign birth (Foreign Births Register), Irish government, foreign affairs service, undated page, read 28 September 2026. Used for: Who can register through a grandparent, and the documents for each of the three people.
- Nationality Act (StAG), section 4, German federal statute database (gesetze-im-internet.de), current consolidated text, read 28 September 2026. Used for: Descent from a German parent, and the generation cut-off for parents born abroad after 1999.
- Confirmation of possession or loss of Polish citizenship, Polish government, interior administration pages (gov.pl), undated page, read 28 September 2026. Used for: How Polish citizenship could be lost before 1999.
- Change to citizenship rules in 2025, Government of Canada (canada.ca), date modified 24 December 2025, read 28 September 2026. Used for: The 2025 rules for births abroad beyond the first generation.
- Citizenship by descent, Italian consular network, Los Angeles office pages, page with checklists dated 29 May 2026, read 28 September 2026. Used for: The routes still open after Law 74/2025.
This guide is our own summary of the sources, not legal advice. Rules change: if it disagrees with the current official page, the official page wins, and the consulate or a lawyer should confirm your case. Rootdossier is not affiliated with, endorsed by, or connected to any government, consulate, embassy, ministry, court or law firm, including the German, Irish, Polish, Canadian and Italian authorities that decide citizenship cases.