How Smartwatch Number Sharing Works (NumberShare, DIGITS, One Number)
What Is Number Sharing?
Number sharing lets your cellular smartwatch use the same phone number as your smartphone. When someone calls or texts your number, both your phone and your watch ring simultaneously. You can take calls, send texts, and stream music from your watch even when your phone is at home, in another room, or powered off. The watch uses its own cellular connection but shares your phone's number and plan through a carrier feature that goes by different names depending on the carrier: T-Mobile calls it DIGITS, AT&T calls it NumberSync, and Verizon uses NumberShare. The functionality is essentially identical across all three — the branding is the only difference.
How Number Sharing Works Technically
When you activate number sharing, the carrier provisions your watch with its own eSIM and connects it to your phone number through their network infrastructure. Calls and texts are duplicated and routed to both devices. Your phone and watch share the same phone number but have separate cellular connections — the watch has its own signal strength, its own data usage, and its own connection to the nearest cell tower. When your phone is nearby and connected via Bluetooth, the watch routes most communications through the phone to save battery and data. When the phone is out of Bluetooth range, the watch switches to its own cellular connection automatically. This transition is seamless — you do not need to do anything, and the other person does not know whether you answered on your phone or your watch.
Carrier-Specific Number Sharing Features
T-Mobile DIGITS
T-Mobile's DIGITS service allows number sharing between your phone and a compatible smartwatch. The wearable line add-on costs ten dollars per month and includes unlimited talk, text, and data for the watch (data on the watch uses your phone plan's data allotment for some usage, though basic messaging and calling consume negligible data). DIGITS also allows you to use your phone number on multiple devices — not just watches but also tablets and secondary phones. T-Mobile supports Apple Watch, Samsung Galaxy Watch, and Google Pixel Watch. Setup is done through the T-Life app: add a paired DIGITS line, then activate the watch through the watch's companion app.
AT&T NumberSync
AT&T's NumberSync works similarly at ten dollars per month for the wearable line. NumberSync supports Apple Watch and Samsung Galaxy Watch models with cellular capability. Activation is handled through the myAT&T app or at an AT&T store. NumberSync gives your watch its own phone number for billing purposes, but all calls and texts are routed to your primary phone number. The watch line includes its own small data allotment for watch-specific functions, with most data usage counting against your phone's plan. AT&T also supports NumberSync for tablets and secondary devices.
Verizon NumberShare
Verizon's NumberShare adds a smartwatch to your plan at ten dollars per month. It supports Apple Watch, Samsung Galaxy Watch, and Google Pixel Watch with cellular capabilities. Setup is through the My Verizon app — select Add a Device, choose the wearable category, and follow the activation prompts. Verizon NumberShare works the same way as the T-Mobile and AT&T equivalents: your watch shares your phone number, rings when your phone rings, and can make independent calls and texts when your phone is not nearby.
Which Watches Support Number Sharing?
Not all smartwatches support cellular connectivity and number sharing. You need a watch with a built-in cellular modem — WiFi-only watch models cannot use number sharing. Apple Watch SE (second generation) with cellular and Apple Watch Series models with cellular support NumberSync, NumberShare, and DIGITS on all three carriers. Samsung Galaxy Watch models with LTE support all three carriers. Google Pixel Watch with LTE supports T-Mobile and Verizon, with AT&T support expanding. Always check your carrier's compatible device list before purchasing a cellular watch. The cellular version of a watch typically costs fifty to one hundred dollars more than the WiFi-only version.
Is Number Sharing Worth Ten Dollars Per Month?
The ten-dollar monthly fee adds up to one hundred twenty dollars per year — a meaningful cost. Number sharing is worth it if you regularly leave your phone behind (gym workouts, short errands, dog walks) and need to remain reachable, if you work in environments where carrying a phone is impractical but wearing a watch is fine, or if you are a parent wanting a connected device for a child without giving them a full smartphone. It is not worth it if your watch is always within Bluetooth range of your phone (the watch handles calls and messages through the phone for free in this scenario) or if you rarely need to make calls from your watch. Try going a week without the cellular feature by keeping your phone nearby — if you never miss it, skip the add-on.
For a complete overview of smartwatch plans and features, see our Complete Smartwatch Plan Guide.
Setting Up Number Sharing Step by Step
The setup process is similar across carriers but starts from your carrier app. First, ensure your smartwatch has cellular capability — check the model specifications. Open your carrier app (T-Life for T-Mobile, My Verizon, or myAT&T). Navigate to Add a Device or Manage Devices and select the wearable option. The app will prompt you to pair the watch with your account and choose the line whose number you want to share. Follow the on-screen prompts to activate the eSIM on the watch — this may require the watch to be near your phone and connected to WiFi. Once activation completes, your watch will show a cellular signal indicator. Test by moving away from your phone (beyond Bluetooth range) and making a test call from the watch. The entire process takes ten to twenty minutes.
Battery Life Impact of Cellular Mode
Using cellular connectivity on a smartwatch significantly reduces battery life compared to Bluetooth-only mode. An Apple Watch in Bluetooth mode typically lasts eighteen to twenty-four hours. In active cellular use — making calls, streaming music, or using data-heavy apps — battery life drops to four to eight hours. For most users, the watch spends the majority of time in Bluetooth mode (connected to the phone) and only switches to cellular when the phone is out of range. To maximize battery life on days when you know you will be using cellular, disable always-on display, reduce notification frequency, and avoid streaming audio over cellular when WiFi is available.
Frequently Asked Questions
What is NumberShare, NumberSync, or DIGITS?
These are carrier-branded names for the same feature: number sharing between your phone and a cellular smartwatch. Verizon calls it NumberShare, AT&T calls it NumberSync, and T-Mobile calls it DIGITS. All cost ten dollars per month.
Can my watch make calls without my phone?
Yes, if your watch has cellular capability and you have activated a number sharing plan. The watch uses its own cellular connection and your phone number to make and receive calls independently.
Do I need a cellular watch for number sharing?
Yes. WiFi-only smartwatch models cannot use number sharing. You need a watch with a built-in cellular modem, which typically costs fifty to one hundred dollars more than the WiFi-only version.
Does the watch use my phone's data?
When connected to your phone via Bluetooth, the watch routes data through your phone. When using its own cellular connection, the watch has a small dedicated data allotment, with heavier usage counting against your phone plan.