150.24. The net obligation refers to the total value of the goods, namely the aggregate of the retail value of the goods and the preparation, delivery, installation and other charges, minus the payment on account.
The payment on account includes the agreed value of goods given to the merchant as a trade-in, the first instalment and any sum received by the merchant before the beginning of the leasing period, including the value of a negotiable instrument payable on demand and the instalments paid in advance, if any.
The instalment obligation refers to the aggregate of the residual value and the periodic instalments other than those included in the payment on account.