Notarised copies of professional qualifications, and many other types of certificates, are often required in order to combat fraud (e.g. identity theft) and to establish intellectual competency for a job application abroad
More commonly, if you are getting a job outside of the UK, almost certainly your new employer will want to know that you have the academic and professional qualifications you claim to have. Of course, you don’t want to part with the originals, so a popular option is to have certified copies made. Your notary will know just what to do. Some countries (receiving jurisdictions) may want the copies to be legalised, and to be notarised in a certain way. For example, documents for the UAE must not have a notarial cover sheet, and the wording, specified by the UAE, is to be placed on the back of the document.
As for legalisation, the UK Government’s Foreign and Commonwealth Office has certain restrictions: click here recognised body to check to see if the UK issuer (the academic institution of University) is an officially recognised body.