The Plaintiff, a freight forwarder acting as agent for a cargo shipper (Shanghai Technology Co., Ltd., hereafter referred to as “Jingao”), engaged the Defendant, an NVOCC, to arrange for carriage of 18 forty-foot containers (FEUs) of cargo from Shanghai to Acajutla in El Salvador. The Plaintiff requested the Defendant to ask for seven days of “free stack” and 14 days of “free use” at the container terminal at the port of destination, meaning 7 days without charge while the containers were on a stack and 14 days without charge while they were elsewhere in the container terminal at the port of destination. The Defendant later confirmed that it had applied for a mixture of 7 + 14 “free stack and use” at the port of destination, and undertook to pay any expenses for time used in excess of the amount requested. The 18 containers were stacked at the port of destination for 23 days before being collected by the consignee, which led to a container demurrage fee in the sum of USD13,356. The consignee paid that fee in order to take delivery of the cargo, but then claimed the sum from the shipper, which in turn claimed it from the Plaintiff. After paying the container demurrage to its client, and after being required to pay the Defendant the container demurrage fee as a result of a court decision in unrelated proceedings, Plaintiff now sued Defendant to recover the sum in these proceedings. The Court held that the Defendant was liable to reimburse the Plaintiff for the container demurrage fee that it had paid to its client, because the Defendant had undertaken to pay any expenses in excess of the amount requested, which constituted a modification of the original agreement between Plaintiff and Defendant.