Bulgaria cannot refuse to amend the gender records of a national who has moved to another European Union country, the Court of Justice of the European Union ruled Thursday in a judgment that legal scholars say could reshape transgender rights across the 27-member bloc.

The preliminary reference came from Bulgaria's Supreme Court of Cassation. It arose from the case of K.M.H., a Bulgarian citizen born in 1990 who now lives in Italy with her partner. She asked Bulgarian authorities to correct her civil registry entries — sex, family name, patronymic, first name and personal identification number — so her documents would match her gender identity.

Bulgarian courts refused. In February 2023, the Supreme Court of Cassation issued a binding interpretation finding no procedure under domestic law for courts to approve changes to gender markers. That ruling tracked a Bulgarian Constitutional Court decision holding that "sex" is fixed at birth.

What did the Court of Justice decide?

EU law "must be interpreted as precluding legislation of a member state which does not permit the amendment of gender data, such as the sex, family name, patronymic, first name and personal identification number, recorded in the civil status registers of that member state, of a national of that member state who has exercised his or her right to move and reside freely in another member state," the Court of Justice held.

The judges also rejected an argument raised in Bulgaria that constitutional rulings blocking legal gender recognition should bind national courts when they apply EU law. National courts, the Luxembourg judges said, cannot treat such interpretations as binding where they conflict with EU law.

What does the ruling change?

The Court of Justice framed the gap between documents and lived gender as more than a bureaucratic issue. When identity papers fail to reflect a person's lived gender, the court said, the mismatch can create serious day-to-day difficulties. It undermines both private life and a person's ability to function normally in another EU country.

For practitioners, the ruling forces a collision with national constitutional limits. A domestic ruling denying legal gender recognition cannot override the EU-derived rights of a citizen who has crossed borders. The decision also pushes free-movement doctrine deeper into identity law, tying the right to amend civil-status records to the practical exercise of EU citizenship.

What did scholars say?

Pieter Cannoot, a law and diversity professor at Ghent University, said the court has "taken an important step towards recognizing a right to legal gender recognition in the EU," linking the ruling to free movement, privacy and nondiscrimination.

Uladzislau Belavusau, senior researcher in European law at the University of Amsterdam and the T.M.C. Asser Institute, framed the judgment as part of a broader shift in EU constitutional law. The ruling, he said, points toward the rise of "sexual citizenship," where recognition of gender identity becomes part of how free movement rights operate.

What does the ruling mean in practice?

Marie Ludwig, senior strategic litigation adviser at ILGA-Europe, which supported K.M.H., said the judgment strengthens the EU's legal basis to act against member states that still block legal gender recognition.

Richard Köhler, expert adviser and litigation lead on transgender rights at Trans Europe and Central Asia, put it more bluntly: "Everyone should have the right to documents recognizing, not denying, who they are."

Denitsa Lyubenova, an attorney and co-chair of the Bulgarian LGBTI organization Deystvie who represented K.M.H., said the ruling addresses a long-standing legal vacuum in Bulgaria. "This case concerns the dignity, equality and legal certainty of trans people," she said. Pending domestic cases must now move forward, she added, even though trans people still living in Bulgaria lack a legal path to update their personal data.

Co-counsel Alexander Schuster said the ruling sends a clear signal to countries that still block legal gender recognition. He pointed to Hungary, Slovakia and Bulgaria as states where many trans people still cannot obtain documents reflecting their identity.

What does the ruling mean for K.M.H.?

For the woman at the center of the case, the judgment carries personal weight. "This decision will finally allow me to have a Bulgarian passport that respects what I have always been since I can remember, since my childhood: A woman," she said. "I chose to live in Italy a long time ago and this formal step will finally allow me to find a job without being discriminated against."

What happens next?

The case returns to Bulgaria's Supreme Court of Cassation, which must apply the CJEU's interpretation. There is no appeal on the point.

The ruling places Bulgarian judges in direct conflict with their own constitutional court. Bulgarian authorities did not immediately respond to a request for comment.