Using an extended SERVQUAL model, this study identifies and compares the importance of service quality to Muslim consumers with an Islamic or non-Islamic bank account in a non-Muslim country, Britain. Eight group discussions and a survey of 300 Muslims were conducted. Five dimensions of service quality were identified, i.e. responsiveness, credibility, Islamic tangibles, accessibility and reputation. These differ in structure and content from the original SERVQUAL developed in a western context and the subsequent CARTER model constructed in a Muslim country. In addition, significant differences were found in the importance of items between Islamic bank account and non-Islamic bank account holders. This study is one of the first to identify and compare the importance of service quality between Islamic and non-Islamic bank account holders in a western non-Muslim country. The results advance our understanding of the impact of culture on SERVQUAL. The study provides insight into Muslims’ bank choice and helps bank managers of both Islamic and non-Islamic banks to focus their attention on the service quality dimensions that matter most to Muslim customers.