Purpose: Consumer purchasing behaviour has changed substantially in the light of recent developments in E-Commerce. So-called ‘multichannel customers’ tend to switch retail channels during the purchasing process. In order to address changing consumer behaviours, multichannel fashion retailing companies must continue to learn how to provide excellent service to such customers. Drawing on expectation confirmation theory, this paper investigates drivers for service quality from the perspective of multichannel fashion customers. Design: /methodology: This paper approaches the topic of multichannel service quality by adopting a social constructionist research paradigm, utilising an abductive approach and an embedded case study research strategy. It aims to explore the lived experiences and perspectives of individuals in the context of an evolving complex and multidimensional phenomenon. The paper seeks information-rich cases and therefore views service quality through the eyes of experienced German multichannel customers. A customer perspective helps to explain the phenomenon of multichannel service quality and helps to disclose the meaning that these customers give to it. The sample size for this research consisted of 18 in-depth interviews and two focus groups including ten focus group participants. As such, a process of methodological triangulation was followed. Findings: Integration quality is identified as the essence of competitive advantage for multichannel retailers. The paper conceptualises integration quality as a catalyst, which plays a supporting role in reinforcing the reactions of the physical and electronic service quality in order to provide an optimised service quality experience. Originality/value: This paper looks at retailer/customer interactions in the context of purchases of a fashion product at a retailer using different retail channels. It highlights the distinctive requirements of multiple-channel systems within which the focus should not only be to enhance and improve physical and/or electronic service quality, but must also be about the integration of the service offers of each channel. The paper contributes to the interpretation of multichannel service quality with a new concept that explains the phenomenon from the perspective of customers.