The availability of social media and 4G Mobile Internet services boosts e-commerce markets. The online payment systems are an integral part of e-commerce. It becomes the increasing need for online shopping and trading to use secure and low cost third-party payment systems. In this paper, we present an online purchase system of BulaPay that is capable of integrating common e-commerce frameworks and shopping cart systems. Using a set of Web services and simple HTML as its interfaces, BulaPay supports complete payment transactions for a business process in a worldwide way. BulaPay not only enables consumers and shop owners to carry out their daily business on the Internet, but also provides them secure, flexible, reliable, and efficient services. This paper presents an overview of the BulaPay system. The comparisons of our system to the existing third party payment systems are given. We also report the results of the end user evaluation on BulaPay.