Management literature has suggested that the advent of mass customisation marks the end for trade-offs between customisation and other competitive priorities (Pine et al. 1993; Westbrook and Williamson 1993; Tu et al. 2001). However, evidence supporting this proposition is anecdotal. This paper examines the impact of product customisation on four competitive priorities, drawing upon the results of a recent survey of 102 U.K. manufacturing firms from eight industry sectors. The study indicates significant compatibility between customisation and quality, volume flexibility, delivery reliability and non-manufacturing costs. On the other hand, trade-offs remain between customisation and manufacturing costs and delivery lead times. The results contradict the initial proposition that customisation can be “free,” and have important implications for firms embarking upon a mass customisation strategy.