In this paper, we present a crossover experiment with a remote usability testing to validate a User Centered Design process applied to a point-of-sale user interfaces redesign, in which the original software product interfaces had a low grade of usability. It was developed as a structured usability remote test plan applied with two samples of users through a crossover experiment. Each sample was composed by 6 participants that had close knowledge about information systems features and other personality attributes obtained by the cashier profile designed through the personas technique. Cashiers are a fundamental role, since they use this software many hours per day, and are very rotative employees, that tend to be young people between 18 and 25 years old. We obtained favorable results, as each sample decreased their execution time in completing the 10 given tasks in more than one minute, which is a valuable time in sales, and it reduced their dependency to ask for help or making operational mistakes in the sale’s process. They emphasized some improved points such as “more understandable labels”, “more striking and pleasant colors”, “better visualization of the components”, and “much easier process to use”.