Today's rental module only supports stock-based products.

That is, if you are going to add an item for 'expenses' - for example freight cost or other additional expenses, the user will have to remove the flag: "IsNonStock" on the rental article registered as 'Expenses' & class: X.

A Goods received (SSA) will have to be created for this article with a price of 0.00 and we suggest using a high quantity to prevent having to create this document so often.

It will then be possible to add an item to the Rental quote specifiying the extra expenses.