eSIM allows you to connect your smartwatch to a mobile network without a physical SIM card. When you sign up for a cellular plan with an eSIM, you will be given a QR code or an ID for you to scan or enter into your smartwatch.

The SIM information will be transferred to the eSIM on your smartwatch, and you will be able to make phone calls and send and receive messages without you to carry the phone with you. 

What are eSIM and its purpose in Smartwatch

eSIM is the short form for embedded Subscriber Identity Module. It is an integrated microchip mounted inside your smartwatch, replacing the traditional SIM card which stores all the identity information about the network provider and cellphone user.

The specification of eSIM is defined by GSMA, a global organization formed in 1995 to unify the mobile ecosystem helping businesses and society to prosper. The latest technical specifications are SGP.22 V3.0 published on 19 October 2022.

The SIM information on the eSIM will contain below data:

• Network Provider
• IMEI number
• ICCID
• MEID

With this information, you will be able to make phone calls and allow data traffic sent between different network operators. Your smartwatch will be enabled with cellular capabilities, allowing it to connect to cellular networks and perform functions like sending messages, streaming music, and receiving notifications without the need for a paired cellphone to be nearby.

How eSIMs are embedded in Smartwatches and activated

The form factor for eSIM is MFF2. It is the smallest among all the five SIM form factors. All the other four form factors have to be inserted into a device, except the eSIM form factor which needs to be embedded.

MFF2 stands for Machine-to-Machine form factor. Its dimension is 5mm x 6mm x 1mm. This eSIM form factor will allow any device like a smartwatch to connect to a carrier.

The eSIM will be soldered (embedded) directly onto the circuit board of the smartwatch during manufacturing. Manufacturers continue to innovate and smaller form factors like Wafer-Level Chip-Scale Packages (WLCSP or CSP) are being introduced, with sizes less than 25% of the MFF2.

Currently, the size of the eSIM chip can be smaller at 2.5mm x 2.3mm x 0.2mm in dimension. This allows the eSIM to be embedded in the smartwatch, and still have enough room to cater to other components like Bluetooth SoC, Battery charger SoC, Accelerometer, Gyroscope, etc.

Here are the common smartwatch makers that have eSIM inside their watches:

• Apple Watches
• Samsung Galaxy Watches
• Samsung Gear
• Huawei Watch 2

You can see the video from GSMA to understand how eSIM works:

Advantages of using eSIM over traditional SIM cards

(1) With the eSIM, you can switch from one network operator to another easily, for example switching your cellular plan from T-Mobile to AT&T.

(2) You do not need to take out an existing SIM card from your device and collect a new SIM card from the new network operator. What you need, is to get the new eSIM information from the cellular vendor, and overwrite over existing eSIM data on your device.

(3) eSIM utilizes much smaller space than a nano-SIM card, and this allows smartwatch makers to put the eSIM chip on its circuit board. Since there isn’t any opening slot, your smartwatch will be protected from moisture and dust, making it more reliable.

(4) When compared with a traditional SIM card, eSIM is an environmentally friendly solution. There will be fewer components used like the SIM card slot, connector, and PCB wastage into the environment. It also has lower CO2 emissions.

(5) eSIM enables simplified management of subscriptions and connections. As a user, you no longer have to manage multiple SIM cards. For businesses, it allows remote management of subscriptions and opportunities to expand businesses into new emerging markets.

Disadvantages of eSIM in Smartwatch

(1) In case your smartwatch cannot be used or is faulty, you will not be able to take out the eSIM and use it on another smartwatch. You need to contact the eSIM provider, which is the cellular plan vendor.

(2) Currently not all smartwatch makers accept eSIM, it is not a standard specification, therefore you still have to limit your selection and choose smartwatches with eSIM capabilities.

(3) The activation of eSIM requires the scanning of a QR code or downloading the SIM profile from the cellular operator. This is new to most consumers and may pose a hindrance to people who are not tech-savvy.

(4) Some countries have strict regulations on the usage of SIM services. They still require users to register their identity with the local cellular network operators or insist on using physical SIM cards for security purposes. That may limit you from using your eSIM in the country.

Steps involved in setting up eSIM on a Smartwatch

You can activate your eSIM by pairing it with your smartphone. If you have an Apple Watch, you will pair it with your iPhone.

Before setting up the eSIM on your smartwatch, make sure your carrier supports eSIM Carrier Activation. With that, you will be assigned a unique eSIM when you purchase the cellular plan from them. Activation can also be done using a QR code by scanning it using your smartphone.

(1) Setting up eSIM in Apple Watch

Step 1. Open the Apple Watch app on your iPhone

Step 2. Tap the My Watch tab, and tap Cellular

Step 3. Tap Setup Cellular

Step 4. Follow the instructions on the screen, per your chosen cellular provider

(2) Setting up eSIM in Samsung Watch

Step 1. Open the Galaxy Wearable app on your Samsung phone

Step 2. Pair your Samsung phone with the Galaxy Watch through the Bluetooth

Step 3. Tap the Watch setting and follow by tapping on Mobile plan to scan for the cellular network

Step 4. Follow all instructions on the screen per the cellular provider

(3) Setting up eSIM in Huawei Watch

Step 1. Open the Huawei Health app on your Huawei smartphone and select eSIM management

Step 2. Pair your Huawei phone with the Huawei smartwatch

Step 3. Tap Activate Via QR Code

Step 4. Use your Huawei smartphone to scan the QR code provided by the cellular provider

Step 5. The eSIM profile will be transferred Over The Air to your Huawei smartwatch

eSIM Card You Can Consider To Purchase

Planning to go overseas for a holiday? If your phone has the eSIM feature, you can consider getting any of the eSIM cards or travel eSIM below. This will allow you to use local data, instead of paying huge roaming charges when overseas.

(1) aloSIM

aloSIM is a Canada-based tech company. With its eSIM, you can stay connected in 130+ countries by loading prepaid eSIM data packages onto your smartphone.

Choose a data plan and install it instantly on your device. No need to insert a SIM card or visit their stores to purchase. Everything can be done online.

(2) Airalo

Airalo has eSIMs for more than 200 countries and territories. It partners with local mobile operators to sell plans through its eSIMs conveniently on its platform. It was founded in 2019 and its HQ is located in Singapore.

In Singapore, it works with SingTel (the country’s largest mobile operator) and offers Singapore eSIM called Connect Lah! You can manage your eSIM easily on the Airalo website or its apps (Android and iOS). However, you cannot call or text because it is a data-only eSIM. No Singapore phone number is given.

What makes Airalo different from other eSIM card providers, is that they work with local telco companies all over the world. This allows them to have better local coverage in each country.

(3) Holafly

Holafly is a Spain-based internet company that offers unlimited data plans in many countries, which other eSIM providers don’t. It will be a great saving if your data usage is huge.

You will receive a QR code immediately in your email after you sign up for their travel eSIM. Scan the QR code with your cellphone camera, and within minutes you will be connected to the internet in your visiting country.

Holafly has very good advice on their website for the user who wants to buy their eSIM: Validate your phone is compatible with eSIM and is unlocked by the local mobile network operator before making the purchase. You can also chat with the support team to check if your phone supports eSIM.

(4) Nomad

Nomad is a United States tech company founded in 2020. It offers eSIM services in more than 100 countries and has competitive pricing in Asia, Europe, North America, and Oceania.

They work mainly with cellular operator Truphone but we are seeing them signing deals with others like JoyTelecom (mostly APAC), AIS (in Thailand), and Telkomsel (in Indonesia). This has allowed them to offer faster and more competitive data-only plans.

(5) SimOptions

SimOptions is headquartered in Hong Kong and it offers eSIMs with local phone numbers and SMS messaging and calling capabilities.

The company was established in 2016 and has various eSIM packages, ranging from 1GB to 100GB, depending on the country you want to visit. Currently, SimOptions covers 160 countries for its eSIM services.

(6) Ubigi

Ubigi is a relatively new player. It is backed by NTT DoCoMo from Japan, the largest mobile operator in the country. It offers eSIM services in over 190+ countries with a wide range of prepaid data plans.

The company also offers global cellular connectivity solutions for Connected Cars such as Alfa Romeo, Jeep, Fiat, Maserati, Jaguar, and Land Rover. This allows car owners to access the internet and enjoy their car’s infotainment system.

Final Thoughts

According to a study by GSMA (GSM Association), by 2030 eSIM will account for 76% of all smartphone connections and this will lead to more smartwatch makers adopting eSIM in their devices.

eSIM market size will reach $8.5bn globally by the end of 2022, and Google and Samsung planning to follow Apple in eliminating their SIM card slot in their smartphone designs, the market expects to grow even larger.

We hope this article will help consumers be aware of the benefits of eSIM technology bring to us, and embrace eSIM in more of our daily devices, not just smartwatches, and smartphones but all other devices with internet connectivity.