Deleting associated users in WHMCS if they are not associated with any other client account would involve custom scripting or development work. This is because WHMCS doesn't have a built-in feature for this specific scenario.

Here's a general outline of the steps you would need to take:

1. Identify Associated Users:

   • Determine how you'll identify the associated users who are not linked to any other client account.

2. Develop a Script:

   • Write a script (likely in PHP) that will perform the following tasks:
     • Identify associated users not linked to any other client account.
     • Delete these associated users from the WHMCS database.

3. Backup Database:

   • Before implementing any script that involves deletions, it's crucial to create a backup of your WHMCS database. This ensures that you can recover in case of any unexpected issues.

4. Testing:

   • Test the script in a controlled environment (e.g., a staging or development instance of WHMCS) to ensure it functions as intended.

5. Implement Script:

   • Once you're confident in the script's functionality, implement it on your live WHMCS installation.

6. Regular Maintenance:

   • Set up a schedule to run the script at regular intervals, as needed.

Please note that this is a general outline and the specific implementation details would depend on your specific WHMCS setup, including how associated users are defined and stored in your database.

If you're not comfortable writing this script yourself, or if you have specific requirements, I recommend consulting with a developer or WHMCS expert who can create a custom solution tailored to your needs. They can also ensure that the script complies with best practices for data privacy and security.