You can disable any user from your database by following the path below:

Screen of a specific user

To mark a user as inactive, you will access the "Users" section in the [Users & Clients] menu. Then, access the specific page of the user in question and in his registration panel, access the [Permissions] tab.

When the screen loads, just disable the options below:

This tool aims to extinguish the access of certain users who have broken their relationship with your business, however if your case is a duplicate registration, has the option of merging entries, which can make it easier for you to keep more information about the user, such as reservation history and joining different contacts.

How to merge entries?