This paper examines the sworn translation of certificates delivered by the British General Register Office in the English–Spanish and English–Galician language combinations. It has a two-fold aim. First, it seeks to provide a preliminary overview concerning the specialised vocabulary, in addition to the legal expressions and formulas frequently employed in the aforementioned documents, while offering translation proposals for the target languages referred to. Second, the usefulness of multilingual glossaries extracted from textual corpora for the translation practice is also considered. Although there is a vast body of literature on legal and sworn translation in the English–Spanish language combination, existing resources on the subject in Galician, a minoritised language, are extremely limited. This may represent a hindrance in identifying appropriate translation solutions in that language, but simultaneously makes this piece of research relevant as a starting point for the sworn translation from and into Galician. The paper begins with an introduction to sworn translation and an examination of its main characteristics. The cultural implications present in the translation of official documents are then considered, followed by an examination of the construction of multilingual glossaries as a useful resource for sworn translation. A sample glossary containing vocabulary from documents issued by the British General Register Office, together with translation proposals into Spanish and Galician is then provided, following which the paper is concluded.