This guide shows you how to change the payment date on a bill that is already registered as paid.
The payment date is the date on which you have registered that you have paid your supplier.
First, select the bill.
Click on the small bank icon
Click on the red void button
Then, click on Yes, void the payment
A confirmation will be then showing up in red. Go back to your bill (which is linked under the description).
Press register payment
Insert the new date
Click on Register
You have now changed the payment date on the invoice.