As a provider, there are always cases where you need to check if certain invoices have been paid. Admin Invoice Notifications For WHMCS allows you to set notifications for invoices to be notified when they are paid (or not paid).
The notifications can be sent either via admin support ticket or via the WHMCS notification system. When creating a new notification you can add a text so that your team knows what to do.
Setup or modify invoice notifications:
Setup new notification on payment:
Setup notification if invoice is not paid by date X:
Admin overview page:
Admin ticket notifications:
WHMCS notification system: