Information Systems (IS) sourcing consists of the delegation of all or any part of the technical resources, the human resources, and the management capabilities associated with providing IT services to the external vendor. This can range from insourcing to domestic outsourcing, offshore outsourcing, nearshore outsourcing and any such variants. The sourcing organizations (clients) increasingly look at the capabilities of the vendor as a benchmark for the quality of the service rendered by the vendor. The capability maturity model is one such preferred scale for assessing the capabilities of the vendor. However, such a capability model does not exist for a client which ventures or is about to venture in a sourcing relationship. The purpose of this paper is to isolate the key IS capabilities that a client could develop to succeed in a sourcing relationship. This represents the first step in developing a client sourcing capability model.