Purpose – Different from the previous organizational citizenship behavior (OCB) literature, this study aims to propose an OCB-O (organizational citizenship behavior toward organizations) and OCB-I (organizational citizenship behavior toward individual coworkers) driven mechanism for the formation of OCB-C (organizational citizenship behavior toward customers). Based on the social exchange and agency theories, the authors propose that perceived leadership support and work autonomy contribute to both OCB-I and OCB-O, which contributes to proactive and reactive customer service attitude as well as OCB-C. Design/methodology/approach – A three-wave survey was conducted in five-star hotels in Mainland China, and a sample of 410 hotel frontline employees was used to test the model. Findings – Findings of the study suggested that perceived leadership support positively led to OCB-O and OCB-I while work autonomy led to OCB-I, demonstrating the importance of employees’ perceived leadership support on motivating employees to perform OCB-I and OCB-O. OCB-I and OCB-O directly improved OCB-C, confirming the proposed spillover effect from OCB-I and OCB-O to OCB-C. OCB-I supported both proactive and reactive customer service attitudes, revealing OCB-I as more effective than OCB-O on influencing employees’ service attitudes. Furthermore, OCB-I, OCB-O and proactive customer service attitude lead to OCB-C. Practical implications – This study suggests that it is important for leaders to show care and support to employees and design jobs with a certain level of flexibility, so that employees are motivated to go the extra mile to do a good job. When employees make helping others a habit, they will provide more genuine care to customers and do a better job in serving customers. Originality/value – This study supports the spillover mechanism of OCB-I and OCB-O on OCB-C. Specifically, the spillover mechanism starts from a workplace-driven model with employees’ perceived leadership support and work autonomy to enhance OCB-O as well as OCB-I. Then, spillover effects stem directly from OCB-I and OCB-O to OCB-C and indirectly to proactive customer service attitude.