Also, I have heard back from Quickbooks Online support that there is no existing email alert for a failed credit card transaction (including Sales Receipt). There is only an on-screen error message. And I think that means no Sales Receipt actually gets created in Quickbooks. Is this why the PandaDoc failures are not showing up in the Quickbooks Online credit card history (https://app.qbo.intuit.com/app/masfailures)? Is PandaDoc team continuing to work on the PandaDoc/Quickbooks integration, so that we can get notified whenever there are failures? Because it's looking like the current integration wouldn't allow Quickbooks Online to capture PandaDoc failures even if we could get Quickbooks notifications. (Perhaps it would be better if the PandaDoc/Quickbooks integration instead created an Invoice? or saved the customer's card details? Instead of trying to create a Sales Receipt, since Sales Receipts sometimes fail without any kind of alert).

Side note: Some of our franchise teams use Quickbooks Payments (a different service than Quickbooks Online, but it is connected to the Quickbooks Online account). For the teams that use Quickbooks Payments, it looks like their Quickbooks Payments history is able to capture the PandaDoc payment failures. This is not a good solution for all our teams, since only some of our teams use Quickbooks Payments (whereas all our teams use Quickbooks Online)-- Plus, it was my understanding that the integration is for PandaDoc to connect with Quickbooks Online. But I am telling you this observation in case it helps the development team. :)

Currently when a payer added the card details, the document status changed from waiting for payment into paid. I hope it will stay in waiting in payment unless the payment was successful and a confirmation has been received. A two-way sync between PandaDoc and the payment gateway in this case.