Abstract: A method and system for determining the weight of an object, such as a shipping container, comprises a plurality of portable weighing units. The weighing units are attachable to the ISO corner connectors of the shipping container. The shipping container is lifted and its weight is then supported by the portable weighing units. The portable weighing units are arranged such that the load applied by the weight of the shipping container passes through respective load cells in each weighing unit in the required direction of loading to ensure an accurate reading from each load cell. The system also includes software enabling a customer to book a weighing service and software to facilitate weighing of the shipping container and transmitting weight data for the shipping container to the customer or to a third party.