To make the government smart has become a crucial issue for sustaining worldwide, competitive advantage. Smart government refers to utilize information and communications technologies (ICT) to improve the national development and the quality of people living. Many developed countries have implemented e-invoice to improve business environment, taxation process, and public service. The Uniform Invoice, with five formats, was originally designed to enhance the taxation mechanism in Taiwan. To improve the administrative efficiency of transaction process and taxation, the e-invoice platform had been developed in the past decade. The focus of this study is to understand the impediments and proposed solutions during the e-invoice implementation and promotion. In this case study, we summarized the e-invoice evolution process into three phases: (1) the paperless phase, (2) the diffusion phase, and (3) the cloud-enabled phase. The coevolutionary adaptation process was drawn as our analytical framework. The findings can provide preliminary understanding of how an integrated e-invoice platform can enable the development of smart government.