T-Mobile just revealed its answer to AT&T’s NumberSync technology, which lets customers use one phone number across all their connected devices. T-Mobile’s version is called Digits and it will launch in a limited, opt-in customer beta beginning today before rolling out to everyone early next year.

“You can make and take calls and texts on whatever device is most convenient,” the company said in its press release. “Just log in and, bam, your call history, messages and even voicemail are all there. And it’s always your same number, so when you call or text from another device, it shows up as you.” When it leaves beta, Digits will cost an extra monthly fee, but T-Mobile isn’t revealing pricing today. “This is not going to be treated as adding another line to your account,” said COO Mike Sievert. “Expect us to be disruptive here.”

It’s basically Google Voice turned up to 11

And while its main feature is one number for everything, Digits does offer T-Mobile customers another big perk: multiple numbers on the same device. This will let you swap between personal and work numbers without having to maintain separate lines and accounts. You can also give out an “extra set” of Digits in situations where you might be hesitant to give someone your primary number; this temporary number forwards to your devices like any other call. You can have multiple numbers for whatever purposes you want, based on T-Mobile’s promotional video.

In some ways, this sounds like an evolved take on Google Voice. “Businesses can give their employees Digits to use on their personal smartphones — even if those phones are on AT&T, Verizon and Sprint,” T-Mobile says. And a single Digits number can also be set up to ring multiple people at once. Like Google Voice. Some account relationship with T-Mobile will be required to use Digits on other carriers.

But on a conference call with press, Sievert claimed — as you’d expect — that T-Mobile has worked up a superior option compared to Apple’s Continuity, AT&T NumberSync (which “tacks on” to Continuity’s ideas) and Google Voice. T-Mobile claims it’s been working on the new feature for years.

T-Mobile’s engineers built an entirely new IMS (IP Multimedia Subsystem) service management layer and Identity Management solution. Instead of authenticating devices through SIM cards, DIGITS gives customers their own identity. When someone calls you, they reach you regardless of the device you have in your hand.

“This solution will work across pretty much anything. I’d almost go so far as to say any consumer electronics device,” said CTO Neville Ray. “There are no constraints as there are with these other systems.” He said T-Mobile holds “seven patents and counting” on the backend of Digits. “Nobody is coming up with as pure and as integrated and as simple as a solution for the customer to manage.” When The Verge asked about security and spoofing risks, Ray confidently stated that Digits numbers carry the same security precautions as any other T-Mobile line.

There’s one big, big problem though: Digits doesn’t currently work with iMessage. T-Mobile is encouraging beta participants to turn off Apple’s massively popular messaging platform for the smoothest experience, which might dissuade some people from trying it out in the first place and become a hurdle for adoption.

If you are interested in trying Digits, you’ll need a postpaid T-Mobile account. The beta will be compatible with devices running Android 5.0 and above, iOS 9 and above, and Chrome and Firefox on the desktop. Support for Digits is already built into the dialer on recent Samsung phones (Galaxy S6/S7, Note 5).