Electronic Commerce has greatly improved business by giving it an online platform where a supplier and an institution can do business. The digital firms in Nairobi County are facing challenges such as poor transaction efficiency among others. Digital firms which have not embraced electronic Commerce have been found to be incomplete in operation. The specific objective of the study was to establish the influence of transaction efficiency. The study was anchored on the theory of planned behavior and resource-based view theory. The study was guided by descriptive research design. Stratified random sampling was used to select the target populations of 35 digital firms in Nairobi County. Census sampling was used to select the entire 70 respondents as the sample size. The findings revealed that transaction efficiency, has a significant effect (β=0.659; p<0.05) on performance of digital firms. It can be concluded that the significance of e-commerce in an industry have been recognized. It can be concluded that e-Commerce allows a business transaction to be conducted within a short time. Moreover, it allows real-time business through direct payment therefore improving the performance of firms. The study recommends that digital firms ought to regularly train their personnel on new trend of digital platforms. This will enhance profitability, customer base and online sales.