If you’re based in France and need a certified translation by a sworn translator do make sure the latter is “assermenté près la Cour d’Appel” i.e. has been sworn in at the Court of Appeal, and is not simply “assermenté près le Tribunal de Grande Instance” (TGI). Linguists who have been sworn in at the TGI are only permitted to interpret for asylum seekers and illegal aliens (étrangers en situation irrégulière) as part of the Code de l’entrée et du séjour des étrangers et du droit d’asile (CESEDA, or ‘Code of Entry and Residence of Foreigners and the Right of Asylum’); they are not authorised to carry out sworn translations. A ‘certified’ translation carried out by someone who is assermenté près le TGI will not be valid, and will have to be re-translated by a sworn translator. You can download up-to-date lists of sworn translators on the Court of Cassation website here.
For more information see the FAQ on the SFT (French professional translators’ union) (in French).