Web Services composition is a new emerging approach of developing Web Services. It consists of aggregating a set of Web Services to create more complete Web Service with wider range of functionalities. It is an implementation of Service Oriented Architecture (SOA) that aims to achieve loose coupling among interacting software agents. In this project, we employed this new technology to develop an integrated online payment system (iPayment). This system composes multiple online payment Web Services in one application. iPayment provides users with cost-effective way to handle all their payment's transactions of different agencies using a single online application. iPayment speeds up the payment process, reduces the amount of registration information submitted by the clients and provides wide range of payments services to potential clients. It is designed to be scalable, so it can integrates easily new payment service of other agencies.