Electronic payment (e-payment) is a subset of an e-commerce (EC) and critical to enhance customer loyalty. A well-designed e-payment service creates new commercial advantage and should be protected as intellectual property. This research develops an ontology roadmap using computer assisted methods to classify e-payment patents. The results of roadmap provide patent portfolio visualization which helps EC enterprises utilize strategic information for competitive advantages. This research also employs patent value indicators to benchmark patent portfolios. In the case implementation, two leading EC enterprises, Amazon and Alibaba, are studied using their e-payment patents as input to implement the proposed methodology. The roadmaps and value assessment results help to describe their underlying competitive advantages and provide management implications for business development.