Inter-organizational information systems (IOS) play a critical role in today’s organizations and their relationships with business partners. While large organizations began utilizing such systems since their dawn in the 1970’s, SMEs have largely been reluctant to adopt and use these technologies. Given their relative commonness among enterprises, SMEs and micro-firms are particularly well suited to provide the critical mass of adopters needed to exploit network externalities exhibited by IOS. However, studies on adoption of IOS featuring micro-firms have remained scarce. Hence, a special focus on adoption decisions in micro-firms can be of great value to advance the understanding of IOS adoption. A survey is conducted on the influence of inhibitors on adoption of IOS for electronic invoice exchange among German SMEs and micro-firms. Several inhibitors are identified from extant literature restraining SMEs from adopting. In particular, results show that reasons restraining micro-firms are significantly different from reasons restraining larger SMEs
