Using a Smartwatch with its Own SIM and Mobile Number: What You Need to Know
Smartwatches with mobile connectivity are becoming increasingly popular. They allow you to make calls, receive messages, stream music, track workouts, and stay connected without carrying your phone everywhere.
One question we hear quite often is:
"Can I have my smartphone and smartwatch on separate SIMs with different mobile numbers, while still having everything mirror between the two devices?"
The short answer is:
Yes, to a point. But there are some important limitations that apply across most mobile networks and smartwatch platforms.
Let's take a closer look.
The Ideal Scenario
Many customers imagine a setup like this:
Mobile phone
- Own SIM
- Own phone number
- Receives calls and texts
Smartwatch
- Own SIM or eSIM
- Different phone number
- Receives its own calls and texts
While at the same time:
- Notifications appear on both devices
- Contacts stay synchronised
- Calendars stay synchronised
- Health and fitness data sync automatically
- Apps work seamlessly between devices
This is a perfectly reasonable expectation, but the reality depends on which functions you're talking about.
Not Everything Mirrors
Modern smartwatches are very good at synchronising information with your phone.
Most Apple Watches, Samsung Galaxy Watches and Google Pixel Watches can synchronise:
- Contacts
- Calendars
- Email notifications
- App notifications
- Health and fitness data
- Weather information
- Reminders
- Music controls
As long as the watch remains paired with the phone and both are signed into the same Apple, Google or Samsung account, these services generally work very well.
However, phone calls and SMS messages are a different matter.
The Difference Between Notifications and Mobile Services
A smartwatch can mirror information from your phone through:
- Bluetooth
- Wi-Fi
- Cloud services
These are account-based services.
Phone calls and SMS messages, however, rely on your mobile number and the mobile network that delivers them.
This means a watch with its own SIM and its own mobile number effectively becomes another mobile device.
For example:
Phone
- Number: 07123 123456
Watch
- Number: 07456 654321
A call to the phone number will normally ring the phone.
A call to the watch number will normally ring the watch.
The two numbers are independent of each other.
Why Don't Both Devices Ring?
Many customers assume that if a watch and phone are paired, a call to either number should ring both devices.
Unfortunately, this requires specialist network functionality that is not universally available.
Features that would be needed include:
- Multi-device call delivery
- Simultaneous ringing
- Shared calling identities
- Shared SMS delivery
- Network-level call routing between multiple devices
While some large network groups offer proprietary wearable services for specific devices, these solutions typically require dedicated platform support and are not part of standard mobile service provision.
As a result, having two separate mobile numbers normally means having two separate calling and messaging identities.
What This Means for 1pMobile Customers
At present, 1pMobile customers should think of a smartwatch with its own SIM as a separate mobile device.
If your watch has its own mobile number:
- It can make and receive its own calls
- It can send and receive its own texts
- It can use its own mobile data allowance
- It can still be paired to your phone
- It can still receive many notifications from your phone
- It can continue to sync contacts, calendars and other account-based services
But not:
- Calls to your phone number will not automatically ring your watch
- Calls to your watch number will not automatically ring your phone
- SMS messages sent to one number will not automatically appear on the other device
- The two numbers remain separate and independent
The Best Setup for Most Customers
For customers who want maximum flexibility, we recommend Separate Phone and Watch Numbers
This is ideal if you want your smartwatch to operate independently.
You'll benefit from:
- A completely standalone watch
- Mobile connectivity without your phone nearby
- Separate contact numbers for different purposes
- Independent calling and texting
While still enjoying:
- Notification mirroring
- Fitness tracking
- Calendar synchronisation
- Contact synchronisation
- App notifications
For many users, this provides the best balance between independence and convenience.
When Is a Separate Watch Number Useful?
A dedicated smartwatch number can be particularly useful for:
Runners and Walkers - Leave your phone at home while remaining reachable.
Children and Teenagers - A smartwatch can provide a communication device without the distraction of a smartphone.
Elderly Relatives - A simple wearable device can offer easy communication and location sharing.
Outdoor Activities - Useful for cycling, hiking, sailing and other activities where carrying a phone may be inconvenient.
Backup Connectivity - Provides an additional way to stay connected if your phone battery runs flat or becomes unavailable.
Our Recommendation
If you're considering a cellular smartwatch, it's worth thinking about what is most important to you.
If your priority is: Complete independence from your phone: Choose a smartwatch with its own SIM and number.
If your priority is: Sharing calls and texts across multiple devices: Check carefully whether your chosen watch, phone and network support this functionality before purchasing.
For most 1pMobile customers, the simplest and most reliable approach is to treat the smartwatch as a companion device that synchronises notifications and account-based services, while recognising that each SIM and mobile number remains a separate communications endpoint.
By understanding this distinction, you can choose the setup that best matches the way you want to stay connected.