Many families do not know whether their ancestors were Czech or Slovak, and the answer decides which country’s route applies. The two routes have different generations, different documents and a built-in interaction: the Czech declaration is closed to people who are Slovak citizens. This guide helps you reason through the choice, using what the embassies say, and it is not a legal opinion. This guide reflects official pages we checked in October 2026. Rules, fees, forms and waiting times change and differ between embassies, so confirm every detail with the embassy or consulate that will receive your application.
Start with the ancestor’s birthplace
The Slovak route asks for a parent, grandparent or great-grandparent who was a Czechoslovak citizen born in the territory of present-day Slovakia. The Czech route asks for a former Czech or Czechoslovak citizen who lost citizenship before 1 January 2014 or an adult child or grandchild of one. The Czech embassy in Ottawa says that in very general terms a person born in the territory of the Slovak Republic before 1953 and his or her direct descendants might be or should be considered Slovak citizens. So an ancestor born in Slovakia points toward the Slovak route, and an ancestor born in Bohemia or Moravia points toward the Czech route.
| Ancestor born in | Likely route | Why |
|---|---|---|
| Bohemia, Moravia or Czech Silesia | Czech declaration, Section 31 | A former Czech or Czechoslovak citizen who lost citizenship |
| Present-day Slovakia | Slovak descent route | The Slovak route is built on birth in Slovakia, and the Czech route is closed to Slovak citizens |
| Carpathian Ruthenia, now Ukraine | Often neither, depending on residence | As a rule only people from Ruthenia who resided in the Czech Republic after 1945 might be eligible for Czech citizenship, according to Ottawa |
| German-speaking Bohemia | Czech route, with a caution about the 1945 decree | A loss under the decree on persons of German or Hungarian nationality excludes the declaration |
Compare the two routes
| Czech | Slovak | |
|---|---|---|
| Generations | Parent or grandparent of the declarant, or the former citizen | Parent, grandparent or great-grandparent |
| What you must prove | How and when the ancestor lost citizenship, and the line to you | That the ancestor was a Czechoslovak citizen born in Slovakia, and the line to you |
| Form | A declaration | An application |
| Children | Declared for by parents under Section 31(5) | Under 14 may be included, 14 and over apply separately |
| Delays reported | 3 to 6 months after the file reaches the Czech Republic, longer with archival research | Appointments of about 6 to 12 months at the Washington embassy in June 2026 |
The Slovak citizen bar
Under Section 31(3), a person may declare only if he or she is not a citizen of the Slovak Republic on the date of the declaration, and the declaration requires a form stating that you have not acquired Slovak citizenship. If you first acquire Slovak citizenship, the Czech route closes for you. Under Section 31(1), the Ottawa embassy also lists, among the conditions that exclude a declaration, that a person acquired citizenship of the Slovak Socialist Republic or the Slovak Republic after 1 January 1969 and still holds it. Ask both embassies about the order in which to proceed if you think both routes could apply.
The exclusions and the borderlands
- The 1945 decree. The Czech declaration does not apply to those who lost citizenship under the decree on persons of German or Hungarian nationality. See our Sudeten guide and our Hungarian-speaking guide.
- Transcarpathian Ukraine. It is excluded where citizenship was lost under the agreement between Czechoslovakia and the Soviet Union. See our Carpatho-Rusyn guide.
- Those who left before 1953. Their files require comprehensive archival research, according to Ottawa.
Questions to answer before you choose
- Where was each ancestor born, and which state governed that place? See our regions guide.
- When and how did each ancestor leave, and did he or she naturalize? See proving loss of citizenship.
- Which generation is the closest to you with a link to Czechoslovakia?
- Do you or a parent already hold Slovak citizenship?
- What documents exist for each route? See our document guide.
- Do you have other family members whose routes differ?
Use the genealogy first
The choice usually becomes clear when the research is done. Identify the village and the parish, find the baptism, and read the registers. See our complete tracing guide and how to find the village of origin. A family story that the ancestors were Czech or Slovak is a starting point, not an answer.
Illustrative composite (not a real family): A reader’s great-grandfather’s naturalization record gives a village that turns out to lie in present-day Slovakia, with a Slovak baptism in the parish register. His great-grandmother was born in Moravia. She sees that the Slovak route applies through the great-grandfather, and that the Czech route might apply through the great-grandmother, but that acquiring Slovak citizenship first would close the Czech declaration, so she asks both embassies how to proceed.
Common mistakes
- Choosing by family story. Birthplace and documents decide.
- Acquiring Slovak citizenship without considering the Czech route. It closes the Czech declaration.
- Assuming Ruthenia counts as Czech. It is excluded in most cases.
- Ignoring the decree cases. They are excluded.
- Skipping the embassy. Each case is decided by the authorities.
Continue with the Czech declaration guide and the Slovak descent guide, and browse Czech & Slovak Citizenship by Descent. Sources: the Czech Embassy in Ottawa (updated 6 January 2025), the Slovak Embassy in Washington (updated 18 June 2026) and the Czech Consulate General in New York.
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