From the list of invoices, click on the new button and select the type "Have",
then enter the items as for an invoice.
Take into account the message and click on "Yes", then "Validate", Choose the date to have it and print. It is possible to modify the content of the room according to whether the credit relates to all or part of the invoice this allows easy billing even for the invoice auto entrepreneur and certainly simpler than sky billing
Check "If this invoice is settled by a credit note (partially or entirely) ..." in modification of the invoice
having generated the credit, in order to settle all or part of it.
L ist of regulations
From the Sales - Rules (Entering and Editing) menu or Navigation Pane Policy