The application, training and admission process for a Notary is robust and involved. It takes years of legal training to become a Notary Public in the UK.
The following is a simplification of the very involved process that includes studying particular areas of the law as part of a law degree. If those areas were not studied at degree level, they must be made up for later on. After this there is a further two years of distance learning provided by the University College London. Then the prospective Notary must be admitted by the Faculty Office of the Archbishop of Canterbury.
Further details are available here.
To qualify as a Notary Public in the UK, a candidate must:
Be at least 21 years old
Take an oath under Public Notaries Act 1843
Be a Solicitor or be appointed as an ecclesiastical legal advisor
Complete academic training
Complete 2 years of professional training
Be admitted by the Faculty Office of the Archbishop of Canterbury