Mobile Commerce, a subset of e-commerce includes all commercial transactions carried out using a mobile device. This paper deals with the impact of mobile commerce on the cash management of commercial companies. Today, in Rwanda, there are more than 80.8% of mobile users available. It is also increasing day today and in China, about 1.4 billion mobile phone subscriptions had already been registered. Therefore, mobile commerce has a very important role in modern business. In today's technology world, we can say that, without mobile, we could not live comfortably. Similarly, in business, without mobile commerce, it is impossible to survive in the competitive commerce world. The mobile revolution is transforming livelihoods, helping to create new businesses opportunities, and changing the way we communicate, work, and earn and spend income. We test whether M-Commerce can affect the cash management of commercial companies if it is well implemented. The result shows that COPABU Inganzo Yacu and Guangxi Materials Group Co.ltd used the Mobile internet and realized significant increases in their exports and business activities overall and gained more from the use of mobile commerce.