Create a balance customer invoice and reconcile the payment to the invoice

You can check customer balance in Odoo by using the Customer Balance in Invoice/Print module. You can also post original customer invoices with the original data or carry over balances as asset accounts if you do not have the original invoices. Also, the user can reconcile a payment to an invoice directly on the invoice itself by selecting the outstanding payment near the totals at the bottom under “Outstanding Payments” and reconciling it. You can also use batch reconciliation feature within Odoo to reconcile all outstanding payments and invoices at once.

To create a balance customer invoice,

1. Go to the Sales Order Module and select the relevant Sales Order. Then click on CREATE INVOICE.

2. From here, select "Regular Invoice" and then click CREATE AND VIEW INVOICE. (Make sure deduct down payments field is ticked)

3. Then you will be directed to the invoices list of this particular sales order, here you can select the final invoice which is in the draft status

4.  Now you can update the details (Ex. Invoice Date) and click on CONFIRM

To reconcile payment to Invoice,

1. Go to the relevant feed where the payment has been made. Then click "RECONCILE XX ITEMS". 
2. Find the relevant feed in the list on left the side and search for the counterpart entry through the search bar for the invoice  
3. select the counterpart entry  and click on VALIDATE.

4. Once you validate and go back to the invoice, invoice will be updated with the PAID tag