Tracking employee work time is a constant challenge for employers, especially when the employees are not physically working in one location. Unfortunately, at least one court has found that employers can’t use personal cell phone GPS data to establish employees’ hours of work.

A federal district court in Indiana recently held that an employer could not use sales representatives’ GPS data from their personal electronic devices — which were used for both work and personal purposes — to defend an FLSA overtime suit. In this case, the employer wanted to compel the sales representatives to disclose GPS and location data from their phones to show when they were and were not working. The court denied the employer’s request, expressing concern that disclosing GPS data from a personal device would result in tracking the employees’ movements well outside of their working time, which would violate personal privacy standards.

This case serves as a great reminder that employers need to find methods of accurately tracking employee work time without relying on data from personal devices.