Following in the footsteps of competitor AT&T, top four U.S. carrier Verizon is requesting a waiver from the Federal Communications Commission that would allow it to enable Wi-Fi calling.

In the Friday filing, Verizon requested the “prompt approval” of “a waiver of any applicable TTY-related requirements for its IP-enabled wireless services identical to and subject to the same conditions as the waiver recently granted to AT&T.” Since the waiver sought by Verizon would have the same terms as the one granted to AT&T, the carrier argued the approval process should be duly expedited and come without the need for public comment. AT&T’s waiver extends through the end of 2017.

Though Verizon, like AT&T, is seeking a waiver for text telephony (TTY) requirements that are difficult to achieve on IP-enabled services, the carrier said it is in the process of developing and deploying a successor technology called real-time text (RTT) that will “work reliably in an IP environment.” The carrier said in the meantime it will alert customers that TTY services are not supported on IP-based calls to 911 and provide information detailing alternate ways to reach emergency services.

If the waiver is granted, Verizon would be the last of the big four U.S. wireless operators to offer the service to its customers.

After receiving its waiver from the FCC earlier this month, AT&T became the third Tier-1 carrier to add the service. The feature is currently available to AT&T customers with an iPhone 6 or above with iOS 9.

Wi-Fi calling has been offered by T-Mobile to Android users since 2007 and was made available to iPhone customers with iOS 8 within the last year. Sprint also made the service available in April of this year to users of the iPhone 6, iPhone 6 Plus, iPhone 5c and iPhone 5s.

In filing for its waiver, AT&T said the FCC had played favorites in allowing Sprint and T-Mobile to offer the service without filing for the waiver before doing so.