How do you recognize that a customer has open items (unpaid invoices)?
In the sign in you see a red exclamation point next to the customer's name. By clicking on it you open a pop-up where you click on 'Open items'.
How can you correct it?
You see an overview with all invoices of the customer. Click on the three points on the right and then on 'Pay open amount'.
Select the payment method on the left side. The open amount is entered by default on the right side. If necessary, correct this, e.g. if you make a partial payment. Finally, you click on the bottom right on 'Without' or bottom left on 'Print receipt', if you want to print a receipt.
Through one click on 'back to invoice overview' you will get back to the overview website.
As soon as you close the overview you can refresh the data in the Sign In and the exclamation mark will be gone then.