Request for advice: creation of credit note

We have customers who receive a “Bonus” in the form of a credit note if they reach a certain billing amount over a period.

We therefore need to create a credit note for this customer which is not related to a shipment.

In your opinion, it is better to:

Directly create a negative customer invoice without product code (account selection only) via the financial module?

OR

It is better to create a negative sale with a service type product (BONUS)?

THANKS

This what is called in french “ristourne” (I do not think there are different terms).
Normally it should be booked in a specific account (in Belgium: 608 and 708, in France: 609 and 709).
The proper tax must be set depending on what kind of product/service is rebated. It seems also that it is possible to skip the taxes.

So I do not think a tryton product should be filled on the invoice line because this is a purely financial operation.

But now I’m wondering if it would be good to have a way to apply the rebate to the unit price of the corresponding stock moves like it is done with landed cost. This way the margin reports are more accurate.