To find payments and credits that are yet to be applied, you can run the Open Invoices Report and with the filter options, you can view payments and credits only.
- Go to Billing.
- On the Reports tab, under Receivables, select Open Invoices.
- Adjust filters, specifically the Open Transactions option to show Only Credits and Payments. From this report, you can open and review and even apply payments and credits if there are available open invoices.