A construction company contracted to purchase 100 windows in four equal shipments; They paid one-fourth with each delivery; The manufacturer demanded full payment before further shipments on June 1. Which statement is true?

• A. The company must pay one-fourth upon each delivery.
• B. The company has no duty to pay until final delivery.
• C. The company must pay the entire remainder now.
• D. The manufacturer waived its right by failing to demand earlier.

Answer: (A)

Installment contracts lead to payment as shipments occur. Here, the four equal shipments come with the understanding that each delivery triggers a payment of one-fourth of the total price. Because the contract specifies payment per delivery, the buyer’s obligation remains to pay one-fourth with each shipment.

The manufacturer’s demand to pay the entire remaining balance before any further shipments would be an acceleration of payment beyond what the contract provides unless the parties agreed to that change or the buyer breached. A seller’s failure to demand payment earlier does not by itself waive the right to require payment per installment. So the correct statement is that the company must pay one-fourth upon each delivery.