You can view a customer's detailed account activity and aged balances at any time. The Display Statements screen can give you a monthly break down of a customer's financial activities, or you can view the entire history in one shot.
If you have the customer open in the Customer screen, you can view their statement by going to Activities → Display Statement. Otherwise, you can reach this screen by going to Receivables → Display Statements.
Select the desired customer to see their statement. To find a customer, start typing their name in the Customer field and ESC will auto-fill the rest. Keep typing until the correct customer is displayed. If you need to search for the customer by something other than their name, click the down arrow to the right of the field instead. Alternately, if you know the customer's number you can enter that in the field to the right.
Once the customer has been selected their current statement will show on the screen. To see items that have been previously paid off use the Entire History button or use the Previous and Next Month buttons to scroll through the customer's billing history month by month. If you need more detail about any invoice simply double click it and it will be recalled on the Sales Invoicing screen. This screen will stay open when you do this so you can drill down into an invoice then return right back to this screen when you're done.
This screen also allows you to email the statement directly to the customer. To send the statement directly to the customer just click the Email button.