Background Who takes a consequential role in decision-making during the design process certainly has an effect on the end product. A designer who eventually makes decisions also considers multiple factors, and an important one is that of the customer. The characteristics of the relationship between a designer and a customer have changed over time and are influenced by changes in the fashion system. The purpose of this study is to identify and compare the design authorities in the relationship between haute couture designers and their privileged customers. Methods The design cases of eminent haute couture designers from different periods, Charles Fredrick Worth and Oleg Cassini, were selected. Additionally, their underlying design authorities were examined based on various social events and anecdotal evidence. Result The study shows that the structure of the fashion system in society affects the relationship between haute couture designers and their privileged customers and eventually design processes and products. Design authority, which is the degree of the designer`s obedience to customers` requests, determines design decisions. Conclusion The fashion system in the current industry may not follow these results exactly; however, this study can provide a good research basis for design authorities in the design process and allow practitioners to learn about the importance of a customer`s thoughts versus a designer`s.