The purpose of this paper to identify the factors that influence corporate customers adoption of Internet banking services in Kenya, Uganda, Tanzania and Rwanda. The hypotheses are empirically evaluated by using Trade Finance customers of an East African bank as the target sample. Technology Acceptance Model (TAM) is the primary basis for the study. The information gathered from former studies that are mainly concentrating on private customer acts as a foundation for building an extension of TAM suitable for corporate customers. The study involved 137 respondents from Kenya, Uganda, Tanzania and Rwanda. Due to the quantitative nature of the study, the results are analysed with statistical measures. This included the use of SPSS to carry out regression analysis. The analysis reveals that corporate users are not motivated by the same factors as private users. In order to become Internet banking customers, it is extremely important for corporate users to have a system that is easy to use and operate with full support from the bank.