Hi,

Please refer to the following links:

1. https://www.odoo.com/documentation/18.0/applications/sales/sales/invoicing/down_payment.html

2. https://www.youtube.com/watch?v=KSolUpwQzcs

3. https://www.youtube.com/watch?v=WY88M5PNgUY

Hope it helps.

Starting with Odoo 18 there is no Downpayment Product anymore. Reverting back to something like this by applying customization will increase your troubles in future upgrades.

The Downpayment Account now can be defined per Product Category. To mange these, go to Sales -> Configuration -> Product Categories and set the relevant Downpayment Account on each one.
If not set, Odoo will fall back to the Income Account applicable for the Product in question.

If you must, you can change the Account of the Downpayment line in the generated Invoice as well.