Hi jsteffens,

Thanks for joining us here. I can see how convenient it would be to set a pop-up alert when a certain payment is received.

As mentioned on this thread, this feature is not available in our product. Feel free to submit your feedback directly to our product development team using the steps shared on this thread. Your comments are crucial in driving innovation to offer the best QuickBooks experience we can.

At this moment, the best way to keep track of which invoices have been paid is by using the invoice Status column on the Invoices tab in QuickBooks Online's Sales section. If you have Payments set up, the invoice status will automatically change to Paid once the payment is received.

To learn more on QuickBooks Payments, here's a useful article: Sign up for QuickBooks Payments

Have a great day!