Route-by-route checklists of which documents need certified translation for UK visa, settlement and citizenship applications, what UKVI checks on each, and the errors that trigger refusals.
Every UK immigration route has its own document list, and every document on it that is not in English or Welsh needs a certified translation meeting the Home Office standard. These pages take each route in turn and say which documents, which ones people forget, and what the caseworker is checking when the translation lands on their desk. The certification standard itself is explained once, in What is a certified translation, and applies everywhere.
Official Translations: certified translations from £29.95 per page, delivered within 24 hours, accepted by the Home Office, UKVI, and UK courts.