The legalisation office (the FCDO) can legalise all UK documents with an apostille.
Documents that carry an original seal, a stamp, or signature from an official or a public organisation in the UK, don’t need to be certified before legalisation.
A UK document is defined as having originated in the UK or being executed in the UK.
Copies/photocopies of documents
Sometimes, photocopies of the original can be legalised—more on this below.
For photocopies to be legalised, a notary public, or solicitor in the UK, must certify that the photocopies are authentic.