Purpose: Firms are increasingly making customers key stakeholders in their greening processes, requiring them to voluntarily use their resources to benefit the firm. In this context, this paper develops a new construct – tangible customer citizenship behaviour (CCB), i.e. voluntary participation of customer in operational processes of the company beyond normal requirements of exchange. This requires more involvement than the already documented intangible CCB. The purpose of the paper is to then explore whether service quality (SQ) (online and offline) influences such voluntary customer reciprocity in greening. Design/methodology/approach: This study used a virtual survey among 400 customers of e-commerce firms that have adopted greening practices requiring customer engagement and regressions were used to test the hypotheses. Findings: The authors find that both online and offline SQ positively impact intangible CCB but have no impact on customer greening reciprocity (tangible CCB). Additionally, the authors find that offline SQ positively impacts customer greening awareness. However, in spite of the presence of greening awareness and display of intangible CCB, SQ does not have any impact on greening reciprocity. Originality/value: This study introduces to literature a more tangible form of voluntary behaviour on the part of the customer, i.e. tangible CCB or reciprocity. To the best of the authors’ knowledge, it is also one of the first to study the customer as an important stakeholder and participant in a business-to-consumer firm’s operating processes, particularly in greening which has no direct impact on the firm’s core offering. The focus on greening in the Indian context is also novel given the greening costs and requirements and the price competition are very different in emerging market contexts where e-commerce firms are experiencing the maximum growth. © 2021, Emerald Publishing Limited.