Absolutely. Already discussing a maintenance contract.
If you're looking for information on how WHMCS works or its full functionality, here are some general points: whmcsfull work
It sends "Welcome" emails with login credentials, so you don't have to. Keeping customers happy is simplified through: Absolutely
He moved his chaotic spreadsheet into the automated invoicing system. Renewal invoices were sent 14 days in advance, and overdue clients were suspended automatically after three failed attempts. whmcsfull work