Any UK document may require attestation for use in another country. Common documents include:
Educational certificates - degrees, PhDs, diplomas, awards
Teaching certificates - PGCE, QTS, TEFL
Professional membership certificates - Accounting, Architecture etc.
Marriage certificates
Birth certificates
Criminal record checks - ACRO, DBS
Commercial documents - contracts, business agreements, Companies House certificates
This is just a small sample of documents we process. It is not an exhaustive list.