Being able to refuse -decline requests, offers, invitations or suggestions -is necessary in the workplace. Native English speakers (NES) and non-native English speakers (NNES) often use different strategies to form the speech act of refusals (Riddiford & Holmes, 2015). This study investigates the refusal strategies of NESs (n=5)and NNESs (n=5) in Canadian customer service. Six role-plays were conducted to determine the refusal strategies of both groups. Stimulated recall interviews (SRI) provided insights into the participants' use of these strategies. Role play analysis show both groups use reason/explanation the most. NES formed successful refusals more often than NNES. During the SRIs NES were concerned about workplace expectations, and the difficulty of refusing while NNES voiced justifications for refusing. SRIs also uncovered that NNES and NES may use the same strategy for different reasons. Pedagogical implications for language learners working in customer service are given.This thesis is the result of many individuals. I would like to acknowledge my supervisors, Dr. Eva Kartchava and Dr. Michael Rodgers, for all of their insight, support, and encouragement. Thank you so much for your guidance throughout my time in this program. I would also like to acknowledge my fellow research assistants, Fatima, Gillian, and Alexis, who I learned so much from. I am lucky to have had the chance to work with each of you, and it was a pleasure to see the realization of your own projects, and of the projects we worked on together. At Carleton, I also want to thank Codie, Tarah, Alicia, and Ashleigh from SALaDS, the graduate student society, who (during a pandemic) have done a commendable job at organizing online events and reaching out to grad students in Applied Linguistics to keep in touch, provide feedback, and create a sense of community during such an isolating year. I would also like to thank Hiba, Mazen, Alexis, Alex, and Karyn from OCISO, for their help, support, and enthusiasm for this project. I feel truly blessed to have worked with all of you.Finally, I would like thank all my friends and family.