A successful enterprise resource planning (ERP) system ultimately requires loyal useÑproactive, extended use and willingness to recommend such uses to othersÑby employees. Building on interactional psychology literature and situational strength theory, we emphasize the importance of psychological commitment, in addition to behavioral manifestation, in a multilevel model of loyal use. Our empirical test of the model uses data from 485 employees and 166 information system professionals in 47 large Taiwanese organizations. Individual-level analyses suggest that perceived benefits and workload partially mediate the effects of perceived information quality (IQ) and system quality (SQ) on loyal use. Cross-level analyses show that IQ at the organizational level alleviates the negative effect of an employee's perceived workload on loyal use; organization-level SQ and service-oriented organizational citizenship behaviors (SOCBs) of internal information systems staff reduce the influence of employees' perceived benefits. Overall, our findings suggest that IQ, SQ, and SOCBs at the organizational level influence employees' loyal use in ways different from their effects at the individual level, and seem to affect individuals' costÐbenefit analyses. This study contributes to extant literature by considering the SOCBs of the internal information systems group that have been overlooked by most prior research. Our findings offer insights for managers who should find ways to create positive, salient, shared views of IQ, SQ, and SOCBs in the organization to nourish and foster employees' loyal use of an ERP system, including clearly demonstrating the system's utilities and devising viable means to reduce the associated workload. > >