Update WHMCS's tax configuration when sales tax rates change. Make sure to do this as close to midnight or the system cron run as possible.
Update the PayPal® webhook URL. If your WHMCS system URL has changed because you moved the installation, some PayPal modules require this.
Recalculate the Recurring Amount value for a service. You must do this after certain actions, like expiring a cPanel Licensing license.
To ensure that your WHMCS installation can function, your system URL setting must be correct at all times.
You can use the Automatic Updater feature to update WHMCS from directly within the Admin Area.
Upgrade or downgrade a service from the Admin Area or Client Area. If you do this in the Admin Area, you will have additional options.
You can configure Google as your mail provider using SMTP.