Apple's connectivity article explains how a GPS + Cellular watch chooses a link. It uses Bluetooth when the iPhone is near to save power; if Bluetooth is not available it tries Wi-Fi; and if neither is available and you have set up a plan, a cellular model connects to the mobile network. It will join a Wi-Fi network only if the iPhone has connected to it before while linked by Bluetooth, and only if the network is 802.11b/g/n on 2.4 GHz or 5 GHz;
the article says the Series 5 and earlier and the first SE support 2.4 GHz only, and the watch will not join public networks that need logins, subscriptions or profiles. To check signal, open Control Center: the cellular icon turns green with a connection and its bars show strength, and it turns white when your plan is active but the watch is using the iPhone or Wi-Fi. A cellular model can disconnect from Wi-Fi in Control Center; it will not rejoin until you turn Wi-Fi back on, move, or it reaches 5:00 a.m. local time.
Differential
Likely causes of “Apple Watch cellular service is not working”, and how to tell them apart
- 1
The watch is a GPS-only model
What separates it There is no cellular icon and no plan option because the watch is a GPS only model
How to confirm Check the model number; only GPS + Cellular models connect to mobile networks
- 2
The cellular plan is not activated
What separates it The plan is missing in the Watch app because the cellular plan is not activated
How to confirm Add the watch to the plan through your carrier
- 3
The watch is using the iPhone or Wi-Fi
What separates it The cellular icon is white because the watch is using the iPhone or Wi-Fi
How to confirm This is normal, since the watch is saving power, so no action is needed
- 4
Weak signal or Airplane Mode
What separates it There are no bars and no calls because of weak signal or Airplane Mode
How to confirm Move to better coverage and turn Airplane Mode off
- 5
Wi-Fi was manually disconnected
What separates it The watch does not rejoin because Wi-Fi was manually disconnected
How to confirm Apple says it will not rejoin until you turn on Wi-Fi, move, or it is 5:00 a.m.
Before you touch a setting
Record this first — changing settings destroys the evidence
- The model number and whether it is GPS or GPS + Cellular
- The carrier, whether the plan is active and the watchOS version
- The color and bars of the cellular icon in Control Center
- Whether the watch works over Wi-Fi and Bluetooth
Try in this order
0 of 7 completedCheck the model
ReversibleCheck the model, by reading the model number and the Identify page to confirm it is GPS plus Cellular.
Check Control Center
ReversibleCheck Control Center, and look at the cellular icon color and the bars, and then test again to see whether it helped.
Check the plan
ReversibleCheck the plan, and confirm that the watch is on your carrier plan, and then test again to see whether it helped.
Turn Airplane Mode off
ReversibleTurn Airplane Mode off, on the watch and on the iPhone, and then test again to see whether it helped.
Test Wi-Fi
ReversibleTest Wi-Fi, by joining a Wi-Fi network that your iPhone has used before, and then test again to see whether it helped.
Restart both
ReversibleRestart both, by restarting the watch and the iPhone, and testing again, and then test again to see whether it helped.
Remove and re-add the plan
ReversibleRemove and re add the plan, and only if the carrier asks, unpair and pair again keeping the plan.
Model-specific
What is true of this model and not of its siblings
- Cellular models
- Apple's Identify page lists separate GPS + Cellular model numbers for each watch, for example A3001 to A3003 for the Series 10 cellular aluminum, and Apple's Identify page says cellular models carry a colored ring on the Digital Crown.
- Wi-Fi bands by model
- Apple's tech specs list 2.4 GHz and 5 GHz on the Series 6, 7, 8 and Ultra, and Wi-Fi 4 (802.11n) on the Series 10, Ultra 2 and SE 2.
- Repair cost
- Checking signal and the plan costs nothing; the plan itself is a carrier charge. A radio that never connects is hardware: Apple's out-of-warranty battery service is $99 and repair fees ran from $199 for an SE 2 to $499 for an Ultra at launch, per MacRumors.
- Other models this page answers
- These steps also fit models Apple Watch Ultra 2, Apple Watch Ultra, Apple Watch Series 8, Apple Watch Series 7, Apple Watch Series 6.
Stop boundary
When this stops being a self-service repair
- !If the plan is active and the watch shows no signal anywhere, contact the carrier, then Apple
- !If you switched carrier or number, ask the carrier to re-provision
- !If the watch never shows a cellular icon and is a cellular model, book Apple service
Evidence ledger
Sources behind this answer
How the watch chooses Bluetooth, Wi-Fi or cellular, compatible Wi-Fi, the 5 a.m. rejoin and signal icons.
Keeping or removing the cellular plan.
Reconnecting the pair.
GPS versus GPS + Cellular model numbers.
The Apple Watch line and its generations.
Exact questions
Common questions
How do I know if I have cellular?+
The model number differs for GPS and GPS + Cellular; Apple's Identify page says the cellular models have a colored ring on the Digital Crown, red on most and orange on the Ultra.
What does a green cellular icon mean?+
Apple says it turns green when you have a connection, with bars for strength.
What does a white icon mean?+
The plan is active but the watch is using the iPhone or Wi-Fi.
Why will my watch not join Wi-Fi?+
Only networks your iPhone has used, and not public networks needing login.
Does the SE support 5 GHz?+
Apple says the first SE and the Series 5 and earlier use 2.4 GHz only.
When does it rejoin Wi-Fi?+
After you turn Wi-Fi on, move to a new place, or it is 5:00 a.m. local time.
Can I use the watch without my phone?+
Yes on Wi-Fi, and on a GPS + Cellular model on a plan.
Should I keep my plan when unpairing?+
Keep it if you will pair again; remove it if you sell the watch.
Do the Ultra and Series 10 differ?+
Both have GPS + Cellular versions with different model numbers.