If you need to take a "quick look" of whether a Sales Invoice has been paid from the Sales Invoice transaction list, you may consider pulling out additional fields such as "DatePaid" and "AmtPaid" onto the Sales Invoice transaction list.
From the Sales Transaction list, go to the Edit menu and select Customise List View function, then add the “AmtPaid” and “DatePaid” fields to the Sales Transaction List. DatePaid will show the last payment date (if you have received multiple partial payment for the invoice) and the AmtPaid will show the accumulated amount paid for the invoice.
If you need to find out the full payment detail, such as the cheques that paid for an invoice, then you may have to use the Payments History function from the Enquiries menu.