The UK system for obtaining a certified translation differs to many other countries. It does not have a system of sworn translators but instead you can obtain a ‘self-certification’ from a UK translator.
According to the UK government, a certified translation should include:
- a statement from the translator declaring that it’s a ‘true and accurate translation of the original document’
- the date of the translation
- the full name and contact details of the translator or a representative of the translation company
Technically any translator based in the UK can carry out this self-certification, however, the UK Home Office and most official bodies require the translations to be carried out by a member of a professional body of translators, such as the ITI (Institute of Translation & Interpreting) or the CIOL (Chartered Institute of Linguists). These institutions provide their members with either a seal/sticker or a member’s logo to prove professional qualification. If a translation agency is a member of the relevant official bodies, they can also provide a certificate of accuracy.
In addition to this, you can get a translation countersigned by a solicitor, signed in the presence of a notary or get certification provided by the applicant's embassy or consulate.
This differs from certification in many other countries. In Portugal, for example, after a translation is carried out by any professional translator, it is then certified by a notary, solicitor or lawyer where the translator swears that it is translated to the best of their abilities.
When obtaining a UK certified translation, it is always worth checking with the authorities involved whether a self-certified translation is sufficient or if they would like it countersigned by a solicitor or notarised.
https://www.gov.uk/certifying-a-document
https://www.iolante.com/certified-uk-translation/information-clients/uk-certification-rules/
https://bellingua.co.uk/2018/10/21/certified-translations-myth-busting-faqs/