Apple’s iOS 9 operating system, which rolled out to the public on Wednesday, technically has the capabilities to enable Wi-Fi calling for AT&T customers with iPhones. According to a new report, however, AT&T can’t activate it until it gets the green light from the appropriate authorities.

Speaking with Phone Scoop recently, AT&T said that it just needs the FCC to say it’s OK to roll. The news site explained that there’s some relation to TTY functionality, which adds additional functionality for folks hard of hearing, and proper support for operation over Wi-Fi networks. Apparently once that kink is worked out, and the FCC says AT&T is golden, support will be activated.

“AT&T tested Wi-Fi calling through the iOS 9 beta and we are prepared to support commercial launch of the service once approved by the FCC,” AT&T told Phone Scoop. The service apparently still works for early beta testers, but there’s currently no timeline for the full launch for everyone else.