The online payment for products or for the access to payment-based services can be made by means of a range of (mobile) electronic payment systems -(M)EPS. Both the industrial sector and research community, mainly World Wide Web Consortium (W3C), are working on facilitating these payment methods on Web and supporting the multiple users on how they can select the suitable (M)EPS. However, to the best of our knowledge, there were no thorough studies considering consumer's preferences when they support multiple (M)EPS. To address this issue, we have performed a survey on an international participants (n=272) aiming to (i) developed a theoretical model to determine their preferences when they are supporting more than one (M)EPS, (ii) find the most valuable option according to them and (iii) determine the surrounding conditions that support their decision to use a specific (M)EPS. The theoretical framework of this study was based on the Technology Acceptance Model (TAM). According to our statistical analysis (Chi-square test), consumers that can pay using different (M)EPS during their online payment transaction, have a preferred payment system based on its security, fees, usefulness, and ease of use as well as on their favorite Web browser for these transactions. Factor analysis was also performed to identify factors that much influence the (M)EPS. Results revealed that the factors influencing online payment preferences differ from those involved in traditional payment methods. Our findings allowed, therefore, providing practical suggestions for supporting payment processes with Web browsers and the W3C payment Application Program Interface (API).INDEX TERMS Electronic payment systems, mobile payment systems, payment preference, ease of use, perceived security, technology acceptance model (TAM).