Immigration or cross-border legal procedures often call for an official translation of documents such as birth, marriage or death certificates, custody arrangements, passports, visas or other identity documents. But what is an official translation?
In the UK: certified or notarised translation
According to the UK government's guidelines, a "certified translation" must include the date, the name, qualifications, professional membership and contact details of the translator, and a declaration by the translator that they have provided a ‘true and accurate translation of the original document’. Qualified members of the Chartered Institute of Linguists or of the Institute of Translators and Interpreters are entitled to produce certified translations.
For another layer of safety, and to satisfy foreign authorities, you can request a sworn translation. This is a certified translation which has then been endorsed by a solicitor. Similarly to a certified copy of official documents, it involves your translator taking an oath, i.e. swearing that the certified copy is the exact translation of the original document.
Finally, some service may have requested that you provide a notarised translation which requires the involvment of a qualified notary and implies an additional fee.
In France: traduction assermentée, or sworn translation
This is a France only scenario, whereby a translator is endorsed by their local court as guaranteed to produce accurate and faithful translations. There is no such thing as a traduction assermentée outside of France. The nearest alternatives are the certified or notarised translations described above.
Apostilled translation
It applies to certain procedures in countries which have signed the Hague Convention of 1961 may require an Apostille. In the UK, it is dispensed by the Foreign Office. You'll need to obtain the apostille first, then talk to your translator about producing a certified translation of the documents (the apostille is already tri-lingual in English, French and Spanish and therefore doesn't need to be translated in these languages).
Pitfalls of certified translations
Always make sure that the certified translation you work with is duly qualified and authorised to produce official translations. Even if it seems more expensive, a rejected document will not only delay your applications but may end up costing more than you were trying to save. If money is tight, try and find a freelance certified translator who will probably be cheaper than an agency.