You upgraded to the LTE version of the Galaxy Watch8 (44mm) precisely so you could leave your phone at home, yet right now your watch will not make a call, send a message, or pull notifications on its own. When the cellular connection drops out, the watch falls back to feeling like a Bluetooth-only accessory, which defeats the whole reason you paid for the LTE model. The good news is that most cellular faults on this watch come down to a toggle, a plan that needs reactivating, or a connection that simply needs to be reset, and you can usually fix it in a few minutes.
Work through the steps below in order. They start with the safest, fastest checks and only move toward a full reset at the very end, so you avoid erasing anything you do not have to.
First, Confirm You Actually Have the LTE Model and an Active Plan
Cellular only works on the LTE version of the Galaxy Watch8 44mm, which carries the SKU SM-L335U (for example SM-L335UDADXAA in Graphite or SM-L335UZSDXAA in Silver). The Wi-Fi and Bluetooth-only 44mm model, SM-L330, has no cellular radio at all, so if that is the watch on your wrist there is no cellular feature to repair. Confirming the model first saves you from chasing a fix for hardware that was never there.
If you do have the LTE SKU, the next thing to verify is that the watch plan itself is live. With the LTE version you are meant to be able to make calls, send messages, stream music, and receive notifications without your phone nearby, but only when a matching carrier plan is active.
- 1.Open the Galaxy Wearable app on your paired Android phone.
- 2.Go to Watch settings (or the Home tab), then tap Mobile plans.
- 3.Select your mobile service provider and check that the switch is On, which means the plan is activated.
- 4.Tap Plan details to confirm the eSIM has been added.
US LTE service for this watch is supported on AT&T, T-Mobile, and Verizon, so the watch plan needs to be set up with one of those carriers to connect.
Switch Off Airplane Mode and Any Data Usage Limit
Airplane mode disables the cellular radio along with Wi-Fi and Bluetooth, and it is one of the easiest settings to leave on by accident. A data usage limit can also quietly cut off the connection once the watch thinks it has hit a cap, so both deserve a look before anything more involved.
- 1.From the watch's Home screen, press the Power key.
- 2.Rotate the bezel to select Settings.
- 3.Swipe to and touch Connections.
- 4.Make sure Airplane mode and Data usage limit are turned off, which turns the cellular radio back on.
You can also reach Airplane mode faster from Quick settings. Swipe down from the top of the screen to open Quick settings, then swipe to and tap the Airplane mode icon to turn it off.
Make Sure Mobile Data Is Switched On
Even with airplane mode off, the watch will not use the network if Mobile data itself is disabled or set to the wrong connection mode. This is the setting that actually lets the watch send and receive data over LTE rather than relying on your phone.
- 1.On the watch, go to Settings > Connections > Mobile networks.
- 2.Confirm Mobile data is turned on.
- 3.Set the data connection to Auto switch or Always on.
If you are travelling outside your normal coverage area, enable Data roaming from this same screen so the watch can use partner networks. The Mobile networks menu is also where you can review Network operators and the Access Point Name (APN) settings if your carrier asks you to check them.
Force Restart the Watch to Clear a Stuck Connection
A cellular session can hang in a bad state, and a force restart reloads the system without touching any of your data. This often clears a connection that refuses to come back on its own, and it is a safe move to make at any point.
Press and hold the Home button (also labelled the Power button) and the Back button at the same time for at least seven seconds. The screen turns black and the Samsung logo appears, after which you can release both buttons. The watch will boot back up on its own and try to reconnect to the network.
Install Any Pending Watch Software Update
Cellular and eSIM behaviour is handled by the watch's software, so an outdated build can be the reason calls and messages will not go through. Keeping the watch on the current version is one of the more reliable ways to resolve connection bugs that a restart alone cannot fix.
- 1.On the connected phone, open the Galaxy Wearable app.
- 2.Tap Watch settings.
- 3.Tap Watch software update, then Download and install.
You can also update directly on the watch by going to Settings > General > Watch software update and confirming. Either way, make sure the watch has at least a 30% charge before you start, since an interrupted update can cause its own problems.
Run the Built-In eSIM Self-Diagnostics
Samsung includes a diagnostic tool that tests the watch's eSIM directly, which takes the guesswork out of whether the problem is on the watch or the network side. It runs from the Samsung Members app on the phone the watch is paired with.
- 1.On the paired Galaxy phone, open the Samsung Members app.
- 2.Tap Support.
- 3.Choose your Galaxy Watch under Connected device diagnostics.
- 4.Tap Install, then Get started.
- 5.Tap the eSIM icon to run the test.
If the diagnostic does not resolve the issue, it points to something the carrier needs to handle, so contact your service provider at that stage.
Re-Add and Re-Activate the Cellular Plan
If the plan looks present but the watch still will not connect, re-activating it forces the watch to search for the LTE network again and re-establish the eSIM profile. This often clears activation states that got stuck partway through setup.
- 1.In the Galaxy Wearable app, go to Watch settings or the Home tab, then tap Mobile plans.
- 2.Follow the on-screen prompts to activate; the app searches for an eligible LTE network.
For AT&T or Verizon, a QR code obtained from the carrier is required to complete activation, and a watch that has been reset needs a new QR code rather than an old one. If activation still cannot complete, contact your carrier for network-specific assistance, since the issue may sit with the plan rather than the watch.
Reset the Watch and Re-Pair as a Last Resort
If nothing above brings cellular back, a full reset and re-pair is the final step. Be aware that resetting erases the watch's data, and resetting from the watch itself may leave some watch data still saved on the phone, so back up anything important before you begin.
Resetting through the Galaxy Wearable app is the recommended method.
- 1.In the Galaxy Wearable app, go to Watch settings > General > Reset.
- 2.Confirm Reset.
You can also reset on the watch itself via Settings > General > Reset, then confirm Reset. After the reset completes, re-pair the watch in the Galaxy Wearable app and re-activate the cellular plan under Mobile plans, requesting a new carrier QR code if you are on AT&T or Verizon. If the problem persists even after a clean reset and re-pair, contact your carrier and Samsung Support.
Frequently Asked Questions
How do I know whether my Galaxy Watch8 44mm has cellular at all?
Only the LTE version supports cellular, identified by the SKU SM-L335U (such as SM-L335UDADXAA in Graphite or SM-L335UZSDXAA in Silver). The Wi-Fi and Bluetooth-only 44mm model is SM-L330 and has no cellular radio, so it cannot make calls or send messages on its own no matter what you change in settings.
Which US carriers work with the Galaxy Watch8 LTE?
US LTE service for this watch is supported on AT&T, T-Mobile, and Verizon. You need a matching watch plan from one of those carriers, set up and shown as On under Mobile plans in the Galaxy Wearable app, for cellular features to function.
Will a force restart erase my data?
No. Holding the Home (Power) button and the Back button together for at least seven seconds simply restarts the watch and often clears a stuck cellular connection without deleting anything. A factory reset is the only step here that erases data, and it is reserved for the last resort.
Do I need a new QR code after resetting the watch?
For AT&T or Verizon activation, a QR code obtained from the carrier is required, and a watch that has been reset needs a new QR code rather than the one used previously. After resetting, re-pair in the Galaxy Wearable app, open Mobile plans, and follow the prompts, contacting your carrier if you need that fresh code.
What should I do if none of these fixes work?
Run the eSIM self-diagnostics in the Samsung Members app first, since it can tell you whether the issue is on the watch or the network. If the diagnostic and a full reset still leave cellular broken, the problem likely needs carrier or manufacturer support, so contact your carrier and Samsung Support for further help.
