How can I clear an invoice when I recieved payment before the invoice was generated?
I usually send invoices on a monthly basis—at the start of the month, billing for all the previous month’s work on one invoice. One customer paid me at the times of service, and I entered those payments as usual, but there was no invoice they applied to since I hadn’t generated it yet. At the start of the next month, I generated my invoices as usual, including one for this customer, but that invoice # still shows as red even though the customer’s balance is $0.

In the recieve payments section, I tried checking the invoice these payments should apply to, but it says:

"You need to delete this payment from the deposit before you can delete or edit its name or amount.”

How can I mark this invoice as paid and how should I handle situations like this in the future?