Spain's co-official languages and the place names on signs

The short answer

Spain has one official state language and several regional ones that are official alongside it. Article 3 of the Constitution makes Castilian the official Spanish language of the state and provides that the other Spanish languages are also official in their autonomous communities, in accordance with their statutes.[1] That is why the official name of a place in some regions is not the Castilian one, or is two names side by side.

Which form is official is set by regional law, and the five regions this page covers do not all follow the same rule. In Catalonia, Galicia and the Balearic Islands the regional form is the only official form of a place name; the Basque Country requires bilingual traffic signs; the Valencian Community requires both names where a municipality has one in each language.[15][13][12][10][9] XTOUR has not surveyed what individual signs show; this page reports what the laws say.

Which languages are official where

Each statute of autonomy names its own language. XTOUR quotes the names each statute uses, because they are not identical.

The Statute of Catalonia makes Catalan the region's own language and official together with Castilian, and also makes Occitan, called Aranese in the Val d'Aran, official in Catalonia. The BOE's consolidated text records that the Constitutional Court, in judgment 31/2010, declared void the words "y preferente" ("and preferred") in the sentence describing Catalan as the language of normal and preferred use of Catalonia's public administrations and public media.[2]

The Valencian statute names Valencian as the Community's own language and the Acadèmia Valenciana de la Llengua as its normative institution.[6] The Balearic statute names "the Catalan language" as the islands' own language and protects the Catalan varieties of Mallorca, Menorca, Ibiza and Formentera without prejudice to the unity of the language.[7] XTOUR uses each statute's own term and does not rule on how the two relate.

The Basque statute makes Euskera, "the Basque people's own language", official in Euskadi as Castilian is.[3] The Galician statute makes Galician the region's own language and both Galician and Castilian official.[4]

These five are not the only case. Navarre's statute, the Ley Orgánica de Reintegración y Amejoramiento del Régimen Foral, makes Castilian the official language of Navarre and gives Basque official status in the Basque-speaking areas of Navarre, to be set by a regional law.[5] XTOUR has no destination in Navarre, and this page does not cover its place-name rules.

INE's list of autonomous communities uses some of these languages in the communities' own official names: Comunitat Valenciana and Balears, Illes sit alongside Cataluña, Galicia and País Vasco.[18]

Who decides a place's official name

At the level of the municipality, national local-government law allows two answers. Article 14 of the Ley de Bases del Régimen Local says a municipality's name may be, for all purposes, in Castilian, in the other official language of its community, or in both, and that a change of name is official only once registered and published in the BOE.[8] The regional laws then set the rule for every other place name.

• Catalonia. Catalonia's language-policy law says Catalan place names have Catalan as their only official form, except in the Val d'Aran, where the Aranese form is official, and that public signs must match the legal names.[9]
• Galicia. Galicia's language-normalisation law says Galician is the only official form of Galician place names, set by the Xunta, and that signs must match.[10] A new Nomenclátor de Galicia, approved by Decree 27/2026, was published in the BOE on 7 July 2026.[11]
• Balearic Islands. Since the 2016 amendment, the Balearic language-normalisation law says the islands' place names have Catalan as their only official form.[12]
• Basque Country. The Basque law asks official names to respect a place's original Basque, Romance or Castilian form, requires traffic signs to be bilingual, and makes both names official for road signs where they are substantially different. The same law requires printed matter, notices and announcements on public transport services that start in the Basque Country to be in Basque and Castilian.[13]
• Valencian Community. The Valencian law gives the regional government the power to set official names, requires municipalities with a name in each language to show both, and asks for names to be signed in both official languages as far as the official name allows.[15]

The official names of XTOUR's cities

INE's register of municipalities, dated 1 January 2026, gives the official names XTOUR checks its records against.[16]

• Donostia/San Sebastián. INE lists the municipality under both names, joined by a slash.[16] XTOUR's destination is San Sebastián, and its Spain research records Donostia as the Basque name.
• València. INE lists the city as València, in Valencian only, while the province is Valencia/València.[17][16] XTOUR's destination is Valencia.
• Palma. INE lists the municipality as Palma.[16] XTOUR's destination uses the slug palma-de-mallorca to keep it apart from La Palma and Las Palmas de Gran Canaria; see Palma.
• Bilbao. INE lists Bilbao.[16] XTOUR's Spain research records Bilbo as a Basque form, but it is not the name in INE's register. See Bilbao.
• Barcelona and Santiago de Compostela. INE lists a single name for each, Barcelona and Santiago de Compostela.[16] See Barcelona and Santiago de Compostela.

The provinces show the same pattern. INE's list gives Girona, Lleida, A Coruña (listed as "Coruña, A") and Ourense as single names, and pairs such as Alicante/Alacant, Castellón/Castelló and Araba/Álava.[17] The Basque provinces have been officially Araba/Álava, Gipuzkoa and Bizkaia since a state law of 2011 replaced Álava, Guipúzcoa and Vizcaya.[14]

How XTOUR handles two names

XTOUR's Spain research gives each destination an English or Castilian name where one is in common English use and records the regional form as a local name. A slug is an address chosen to avoid collisions, not a statement of the official name. XTOUR's reading is that both names on a sign refer to one place; it never treats Donostia and San Sebastián, or València and Valencia, as two destinations.

What XTOUR does not tell you

XTOUR has not surveyed road signs, station names or street signs in any Spanish region, and it does not say which name a particular sign, ticket or timetable will use. It does not publish language-use statistics or advice on which language to speak. For the regions themselves, see the Spain travel guide, the guide to choosing between Bilbao and San Sebastián, and the Spain country page.