MLD5 - obligation to inform clients of the requirement to register?

We are a small but long running firm and have therefore potentially created many trusts in the past that would now be registerable with the TRS under MLD5.

We have conducted an initial review of past files within the private client department and identified a number of registerable trusts, however, we are now considering whether it would be appropriate to take a more ‘belt and braces’ approach and send a mailshot, potentially to all past and present clients of the firm.

Generally our retainer does not extend to advising clients about future changes to the law, though of course clients may be unhappy if they are not informed.

It would be most helpful to have an idea of how other firms have approached this, or if anyone is aware of Law Society guidance (I cannot find any).