How can I block a customer for non-payment?

For a customer (Basic Data > Customer > Customers (v2), you can set a credit limit in the customer's “general” tab.

You can also manually set a customer order to “credit limit exceeded”. You do this in the customer order itself using the button “Credit limit exceeded”.

You will get a pop-up stating - then click ok.

The status of the customer order is now changed to “credit limit exceeded” and you can no longer click “to deliver”.

This is also filed away in the history, so you can see who and when this was done.

You will also now see “Check credit limit” and “Approve credit” buttons at the top.

If the credit is ok and you want to approve it, you can do so via the “Approve credit” button. The status is changed to “new” and you can proceed with this order.