When a company or individual needs to translate official documents — birth certificates, contracts, deeds, academic diplomas — two terms frequently appear that seem interchangeable but are not: certified translation and sworn translation. Using the wrong format can result in the document being rejected by the receiving authority, delaying legal, administrative, or immigration procedures.
What is a sworn translation
A sworn translation (also called an official translation or authorised translation) is produced by a translator who holds a formal appointment from a public authority — a court, ministry, or government body — and who has taken an oath to guarantee the accuracy of their work. The sworn translator signs and stamps the translation, taking on legal responsibility for its contents.
This type of translation is required in contexts where legislation specifically mandates the involvement of an officially appointed translator, such as:
- Documents for court or legal proceedings
- Documents for notarial registration
- Certificates submitted for nationality applications
- Documents for immigration authorities
The specific title and appointment mechanism varies considerably by country. Germany has *vereidigte Übersetzer*, Spain has *traductores jurados* appointed by the Ministry of Foreign Affairs, and France has *traducteurs assermentés* appointed by courts of appeal. Portugal's equivalent framework is less formalised — the receiving authority should always be consulted to confirm what format it will accept.
What is a certified translation
A certified translation is a professional translation accompanied by a formal declaration — signed by the translator or the translation company — attesting to the accuracy and completeness of the translation relative to the original document. It does not require the translator to hold a state appointment, but the certification statement must clearly identify the responsible party, and depending on the destination country or institution, may need to be notarised or accompanied by an apostille.
Certified translations are the most widely accepted format for private institutions, universities, chambers of commerce, and international organisations. Many embassies accept certified translations for visa and consular procedures, provided the source document has been apostilled where required.
Apostilles, notarisation, and legalisation
Translations — whether certified or sworn — may require additional formalities depending on the destination country:
- Apostille (Hague Convention): A simplified legalisation mechanism for documents circulating between the 125 signatory countries of the 1961 Hague Convention. In Portugal, apostilles are issued by district courts or the Ministry of Foreign Affairs, depending on the document type.
- Consular legalisation: Required for countries that are not signatories to the Hague Convention. The document is authenticated by the destination country's embassy or consulate.
- Notarial recognition: Some institutions require the translator's signature to be notarised, regardless of whether the translation is certified or sworn.
The combination of translation + apostille, or translation + notarisation, is common in immigration processes, recognition of academic qualifications, and company registration abroad. The exact requirement always depends on the receiving authority and the destination country — it is advisable to confirm this before beginning the process.
How to determine which format is required
The starting point is always the institution receiving the document. The key questions are:
- Does the authority require a translation by a state-appointed sworn translator, or will it accept a certified translation from a recognised professional company?
- Is an apostille or consular legalisation required for the source document?
- Does the destination country have specific requirements for the language pair involved?
For documents submitted to Portuguese authorities (IRN, AIMA, courts), a certified translation with a formal declaration of accuracy is generally accepted. For documents destined for countries such as Germany, France, or Brazil, requirements can differ significantly and should be verified case by case.
How M21Global can help
M21Global provides certified translations with declarations of accuracy for the principal language pairs across all major document types, including legal, academic, and corporate documentation. ISO 17100:2015 certified and with over 20 years of experience in official documentation, the team advises on the correct format for each destination authority — reducing the risk of rejection or delays. Where a sworn translation by a state-appointed translator is specifically required, M21Global can direct clients to the appropriate qualified professional in the relevant country.
