On the other hand, an increase in the needs of the parties may encourage the parties to expand their relationship beyond their initial parameters. If the parties accept the amendment and sign additional documents, the duration of an existing agreement may be extended Contract changes are also useful in cases where you and the other party have handled the cases differently from what the contract requires. Suppose Hats for Less sells fascinators to a store called Wedding Hats and the contract guarantees that you send shipments within 14 days. Last year there were some delays because you can`t always get the springs you need to make the fascinators as quickly as you want. Wedding Hats understands the delays and has agreed to the shipment to last 30 days.