There is, generally, no direct legal requirement as such. Organisations choose whether or not to implement the requirements of ISO 27001 based upon the benefits that would be gained by doing so.
However, you should pay close attention to any contractual obligations you may have for protecting the information of clients and other stakeholders.
There is an increasing trend where customers require third party suppliers to implement or certify to ISO 27001, thus making it a legal requirement, by way of a contract.

Transitioning to ISO 27001:2022
If your organisation is looking to transition to ISO 27001:2022, URM’s blog provides practical and invaluable guidance on meeting the new requirements.
URM’s blog explains how the principles of confidentiality, integrity and availability (CIA) can help align your information security controls with best practice
URM’s blog explores ISO 27001 Clause 9.1, what it requires and practical guidance on how to implement this Clause in full conformance with the Standard.
URM’s blog explains the purpose & requirements of ISO 27001 Clause 6.3, types of ISMS change it covers, and key considerations when putting it into practice.

