Volvo Car Open in Charleston will be become the first WTA event to use electronic line calling system on clay. The tournament will use Foxtenn, which is similar to the popular Hawkeye system used on the ATP and WTA tours.

Though electronic line calling systems are thought be generally accurate, questions have been raised about the the possibility that the mark on clay would show the errors of the electronic system. This would cause players and fans to doubt the results of these electronic play calling systems.

Foxtenn system uses 40 high-speed cameras, which generate 100,000 images per second.  These images assist the umpire in calling whether the ball is in or out. In 2018, WTA approved Foxtenn for use on hard courts.