Termination removes the account and all its data permanently. Treat it as final, because it is.
BEFORE YOU TERMINATE
Take a full backup of the account and store it somewhere off the server. Even for a client who left badly, having the data is better than not having it. Give the client notice and a reasonable opportunity to retrieve their own data. Your terms should say how long. Confirm you are terminating the right account. Usernames look alike. Consider whether a domain registered through you needs transferring to them first.
TERMINATING
WHM > Account Functions > Terminate an Account. Select the account, choose whether to keep the DNS zone, and confirm.
AFTERWARDS
The account, its files, databases and mailboxes are gone. Server-level backups will also age out. Do not plan on recovering it.
A BETTER DEFAULT
Suspend, wait out your notice period, take a backup, then terminate. The extra step costs nothing and has saved a great many awkward conversations.
IF A CLIENT IS LEAVING AMICABLY
Give them a full cPanel backup to take to their new host. It costs you a few minutes and is the difference between a bad ending and a referral.
