The concept of service regime is developed to extend and test Miozzo and Soete's service taxonomy. Derived from the synthesis approach of service innovation, the service regime considers sources of innovation, innovation trajectories, and appropriability. Hypotheses on firm patterns of innovation are tested on a dataset of 5711 Taiwanese service firms. We find that service firms have patterns of innovation that are best described as loosely coupled systems with diversified sources of innovation, multiple innovation trajectories, and jointly appropriable mechanisms. The use of Service Regime provides a framework that offers deeper insights into non-technological innovation trajectories and informal appropriation mechanisms for different types of service firms. In doing so, useful insights are offered to managers of service firms and a more complete theoretical model of the nature of innovation in different types of service firms is offered.