Once added, you are unable to delete contacts from your database, but you can deactivate them.
Deactivated contacts can’t be sent emails and no longer count toward your account level.
Deactivated contacts, are essentially deleted contacts. Deactivated contacts don’t count toward your contact billing level. The reason we keep deactivated contacts in your account is only to ensure that they are not re-added accidentally, sent to after unsubscribing… etc. If you are wanting to make room for more contacts (besides upgrading), we suggest deactivating “unengaged” contacts. We can help you with that process.
Check out our article on deactivated contacts for more information.
The only time you could have contacts removed from your account is if you have imported your list but have not sent any emails the contacts yet. You are able to undo your import.