cPanel PartnerNOC invoicing is run on the 15th day of every month. To ensure the upcoming invoice reflects an accurate number of accounts on each license, it is required that Partners review licenses 24 hours prior to invoicing. Should accounts be removed within 24 hours of invoicing it's possible removed accounts may be on the invoice and can't be removed.
Important Information! Licenses for decommissioned servers or suspended accounts must be expired by the Partner to prevent them from being invoiced. cPanel's billing system will always invoice a license if it is active regardless of the state of the server or the accounts within the server.
Additional details about Partner Invoicing can be found in the following article: Partner Monthly Invoice