A sworn, or certified, translation is one that is officially recognised. A sworn or certified translation may be required of any document, of whatsoever nature: the seal and signature of the sworn translator (also known as official, public or certified, depending on the country) gives the translated document the quality of an official document, with the same legal validity as the original. Sworn translations are often required by certain authorities (ministries, courts, education establishments, etc.). 

Gabinete Internacional de Traducciones (GIT) has sworn translators duly recognised by the Spanish Ministry of Foreign Affairs and Cooperation to do, certify and sign sworn translations.

Legalisation: Legalisation is an administrative formality recognising the validity of a public document, confirming the capacity in which the authority signing the document has acted and that the signature on that document is genuine. Legalisation may occur at two instances in the sworn translation of a document. One, prior to translation, refers to the original document and is processed in the country issuing the document. The most common form of legalisation is to append the Hague Apostille to the original document. This is a simplified method of international verification of the authenticity of the document that can be used by the 103 countries that signed the Hague Convention (consult list here). Depending on the type of document, you must take it to one of the authorities competent to issue the apostille: the Secretary of the Governing Body of the High Court of Justice of the corresponding Autonomous Community or the Dean of the corresponding Notarial Association.

Prior to translation, the original document must have all the necessary legalisations (Hague Apostille, if the host State is a signatory of the Convention, or notarisation, endorsed by the corresponding Notarial Association and legalised by the Ministry of Justice, if the host State is not a party to the Convention), as those legalisations must be included in the sworn translation.

The second instance of legalisation refers to the translation itself. According to the Regulations of the Office of Language Interpretation of the Spanish Ministry of Foreign Affairs and Cooperation (published in the State Gazette –BOE– No. 47 of 23/2/96), the signature of the sworn translator must be legalised on any sworn translations into a language other than Spanish (reverse translations). That legalisation must be requested by prior appointment at the Ministry of Foreign Affairs and Cooperation. Sworn translations into Spanish (direct translations) are exempt from legalisation of the sworn translator’s signature.