Back in December, T-Mobile unveiled a new service called Digits, making phone numbers less reliant on a SIM card, and expanding the simple phone number into the smartphone age.

Now that service is live and available to all T-Mobile customers for free on May 31. It's a re-imagining of the phone number, but it's also a way to entice more people to sign up to more expensive T-Mobile One plans.

And for all of its big talk, Digits is a bit confusing, so let's break it down.

What is Digits?

At its core, Digits is T-Mobile's way of utilizing its new IMS (IP Media Subsystem) backend to dynamically direct calls to any device, or store multiple numbers on a single device.

Basically, without the technical mumbo jumbo, it's a way to free the phone number from its legacy place, and to utilize the flexibility data-based nature of Voice over LTE and Voice of Wi-Fi to allow a call to take place, or to be received, in the most convenient place. This is very similar to Google Voice, and to many other Voice over IP services like Viber and Skype, but T-Mobile has one major advantage: it owns the network, and it distributes the phones.

So what can Digits really do for me?

Provided you're on one of T-Mobile's compatible postpaid plans (yes, this is yet another way for T-Mobile to upsell you), Digits can make it easier to manage phone calls in the increasingly inevitable situation you have multiple devices.

The basic idea is that if you receive a call on your traditional T-Mobile number, your phone should ring, along with any device — another phone, a computer, a tablet, even a connected smartwatch — at the same time. You can also make calls from any of those same devices without your phone nearby, and without the need to have a SIM card.

A secondary but for many people equally important feature is the ability to have more than one number available on a single device. So instead of having separate personal and work phones, you can have a single smartphone make and receive calls from two or more numbers.

This sounds a lot like Google Voice

Yes, it does. The major difference here is that T-Mobile is committing to a couple of things that even Google, which creates both Android and Google Voice, can't do:

  • It is integrating Digits directly into the Android phones it sells, working with manufacturers like Samsung to seamlessly add Digits support into devices like the Galaxy S8, Galaxy S7 and Gear S3.
  • It is making it easy to do so-called "SIM replication," which allows you to duplicate a phone number onto a second device, such as another smartphone or a connected smartwatch.

This is in addition to the Google Voice-like Digits app that's available for Android and iOS, to make and receive calls and texts from any device, anywhere. There's also a Digits portal on the web for people who sit in front of a computer all day and want to be able to initiate communications that way. And because the app is available natively and through an app, devices with SIM cards from AT&T, Verizon or Sprint — any carrier, really — can access Digits messages. If you lose your phone, for instance, you can download the Digits app onto a friend's device and make and receive calls and texts from there, too.

Like many cross-platform messaging services, call logs and messages also sync in real-time between devices, which is a huge boon to productivity if you don't always have your phone in front of you.

It's tailor-made for Android

Android is the only platform on which T-Mobile can rely to help Digits grow.

Digits is a cross-platform play, sure, but it is tailor-made for Android. Not only does iOS have its own cross-device communications protocol in iMessage, which may mess with Digits' ability to route texts, but Apple doesn't allow for any system-level alterations, rendering one of Digits' primary use cases moot.

Indeed, Android is the only platform on which T-Mobile can rely to help Digits proliferate, but by potentially limiting half of the population to merely an app-based experience, it is almost immediately cut off at the proverbial knees. Still, Digits has a five-device limit, and can easily be tuned to be used on an iPhone or iPad, especially since as of iOS 10 VoIP apps can take over the lock screen like a regular dialer.

The best Digits experience will always be on Android, and initially is only natively available on the Galaxy S8, Galaxy S8+, Samsung Galaxy S6, Galaxy S6 edge, Galaxy S6 edge+, Galaxy S7, Galaxy S7 edge, Galaxy Note 5, or LG G5 purchased through T-Mobile.

Unlike using the app, which will enable T-Mobile Digits when you log in for the first time, users of the native Digits experience on the above phones need to explicitly enable it in the T-Mobile account app by.

  1. Open the T-Mobile app.
  2. Tap Menu.
  3. Tap on Usage & Plans.
  4. Tap View line details.
  5. Scroll down to the DIGITS tile.
  6. Tap Unlock.
  7. On the unlock page, tap the Unlock button.

Does it cost anything?

All postpaid T-Mobile numbers can now access Digits for free. There is no additional fee at all, which is nice. That means that you'll be able to use Digits on a T-Mobile number and, through the app, any non-TMobile phone over Wi-Fi or cellular.

T-Mobile is also running a pretty nice promotion starting May 31 for those who want a second Digits line for, say, giving to online account signups or Craigslist ads. As long as you start the process with a T-Mobile One plan, upgrading to a T-Mobile One Plus or One Plus International line ($5/mo and $25/mo respectively) gets a second Digits line for free as long as that account type is active.

If you don't want to upgrade to a T-Mobile One Plus plan, an extra Digits line costs $10/mo when AutoPay is enabled.

Learn more

Where do I download the app?

Right here!

On May 31, you'll be able to log into the Digits app and begin using it on any device you want, receiving phone calls and text messages like you would on your main line.

So should I sign up?

Digits is an intriguing product, and an example of what it looks like when a carrier turns next-generation core technology like IMS and HLR (which works to virtualize SIM data on the core network) into something that is truly compelling to consumers.

At its core, Digits is about making the phone number more flexible by putting it — phone calls and text messages — on practically any device regardless of screen size or type. Tablet? Sure. Smartwatch? Absolutely.

The use cases for Digits are plentiful, and that may be its downfall; unless you know exactly why you should use such a service, I feel many people will be intimidated by the prospect of juggling one number across multiple devices or, even more so, multiple numbers on one device. The service's bugs have certainly been ironed out during the beta period, and there's no cost to try Digits once it launches May 31.

See Digits at T-Mobile

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