I bill for hosting quarterly, but have a few customers that pay by mail annually. I have billing automation settings set for 14 days as the default with annually set to 30 to give them enough time to process and send a payment. My issue is getting my annual hosting customers to have their domain renewal included. The due dates doesn't always match up so it generates separate invoices. Even if I set the next due date to the same dates and merge the invoices, the next time cron runs it creates a new domain invoice. problem is for mail in payment customers, once they receive an invoice they send payment and I don't really want to have them receive another invoice a month or two later for the domain renewal.
Any tips on how to deal with syncing domain and hosting invoices so they appear on the same invoice?