Multimodal transport is also known as combined transport and in this transportation of goods under a single contract, but performed with at least two different means of transport; the carrier is liable for the entire carriage, even though it is performed by several different modes of transport . The carrier does not have to possess all the means of transport, and in practice usually does not; the carriage is often performed by sub-carriers. The carrier responsible for the entire carriage is referred to as a multimodal transport operator, or MTO.