To completely delete an account in WHM, you must check the following points.
User account in cPanel
It is possible that the user in cPanel has been left saved. To delete it, as always, we will access WHM > Account Functions > Terminate an account
Entries for the user in /etc/passwd
Within the /etc/passwd file, residues of the user may remain. To delete it, we will only have to edit it and search for the last line, which will correspond to our new user.
nano /etc/passwd
User home directory
Sometimes, even if the copy fails, the home directory for the user remains created, so it is not possible to try the copy again.
To delete their home directory, we will run the following command:
rm -dfr /home/user
DNS zone of the domains
It is also very likely that DNS zones have been created for the domains. So we will have to delete them from WHM > DNS Functions > Delete a DNS zone
User group
The user's file group may have been saved. To delete it:
groupdel user
Delete entries from the httpd.conf file
Finally, we will have to edit the httpd.conf file and delete the virtualhost for the domain:
nano /usr/local/apache/conf/httpd.conf