BackWhat Is an eSIM and How Does It Work?
An eSIM replaces your physical SIM card with a digital profile stored inside your phone. This guide covers how eSIM works, how to activate it on StarHub, how to transfer it to a new device, and how to fix common activation issues.
What Is an eSIM?
An eSIM (embedded SIM) is a digital SIM chip built into your phone at the factory. It stores your phone number, network credentials and plan details, but receives this information wirelessly instead of on a plastic card.
The technology is standardised by the GSMA and built on a reprogrammable chip called an eUICC (embedded Universal Integrated Circuit Card). Your phone does not need new hardware every time you change carriers or add a second line. Your carrier sends a digital profile to the eUICC over the internet, and the chip stores it securely.
Once activated, an eSIM works identically to a physical SIM. You make calls, send messages and use mobile data on the same network, at the same speeds. The difference is entirely in how the SIM information gets onto your device.
How Does an eSIM Work?
Knowing how to use eSIM starts with understanding the activation flow. When you sign up for a StarHub eSIM plan, StarHub creates a digital profile containing your phone number, network authentication keys and plan settings. Your phone downloads this profile over WiFi or mobile data and saves it to the eUICC chip. The chip then authenticates with the StarHub network, and your line goes live.
The entire process takes a few minutes. Here is how it works step by step:
Good to know: You do not need to remove your physical SIM to use an eSIM. Most phones support both at the same time (dual SIM), so your existing SIM stays active while you add an eSIM for a second line.
eSIM vs Physical SIM: Full Comparison
The eSIM vs physical SIM question comes down to setup and management, not performance. Both connect your phone to a mobile network. They deliver identical call quality, data speeds and coverage. The differences are in how you set them up, manage them and what happens when something goes wrong.
So Which Is Better?
For most people in 2026, eSIM is the better choice. It is faster to set up, more secure if your phone is lost, and required for newer devices like the iPhone 17 and iPhone Air, which dropped the SIM tray entirely. Singapore's IMDA regulates all mobile services in the country, and eSIM operates under the same standards as physical SIM.
The one scenario where a physical SIM has an edge: if you frequently swap your number between different phones, popping a card out is still simpler than re-downloading a profile each time. But if your phone supports eSIM (and most recent phones do), there is no downside to using it. Performance and coverage are identical.
How to Check If Your Phone Supports eSIM
Not every phone has eSIM hardware. If you need to check whether your phone supports eSIM, confirm your device is compatible using one of these 3 methods.
1 Dial *#06#
Open your phone's dialer and type *#06#. If you see an EID (Embedded Identity Document) number alongside your IMEI, your phone supports eSIM. This works on both iPhone and Android.
2 Check Your Phone Settings
3 Check the Carrier Lock Status
Even if your phone has eSIM hardware, it must be carrier-unlocked to use an eSIM from a different provider. On iPhone, check Settings > General > About > Carrier Lock. It should say "No SIM restrictions". On Android, contact your carrier to confirm your device is unlocked.
eSIM-Compatible Devices (2026)
Most flagship phones released from 2020 onwards support eSIM. Here is a quick reference by brand.
Upgrading soon? If you are planning to buy a new phone, eSIM support is now standard on virtually all mid-range and flagship models. Some newer devices have removed the physical SIM tray entirely, making eSIM the only option.
How to Activate and Install an eSIM?
Once you have confirmed your phone supports eSIM, learning how to install and activate an eSIM takes only a few minutes. You will need a stable WiFi connection and the QR code from StarHub (sent by email, available in the StarHub App, or via StarHub One Click for Star Plan users).
On iPhone
On iPhones running iOS 17.4 or later, you also have the option to tap and hold a QR code received by email to add the eSIM directly without opening the camera. For full details, see Apple's eSIM setup guide for iPhone.
On Android
How long does eSIM take to activate?
Most StarHub eSIMs activate within 2 to 5 minutes after scanning the QR code. If you are porting your number from another carrier, the transfer itself takes up to a few hours. StarHub will notify you once the port is complete.
How to Transfer Your eSIM to another Phone?
When you switch phones, your eSIM does not move automatically. The transfer method depends on what phones you are moving between. Find your scenario in the table below, then follow the matching steps.
iPhone to iPhone (Quick Transfer)
If both iPhones run iOS 16 or later and your carrier supports it, Quick Transfer is the fastest path. Apple's official eSIM guide covers additional scenarios.
Android to Android (QR Code)
Samsung users also have the option to transfer during the Smart Switch setup process. When prompted, choose the option to transfer your SIM instead of scanning a QR code.
Android to iPhone (QR Code or Google Settings)
Apple supports eSIM transfers from Android phones to iPhone. The steps below follow Apple's official Android-to-iPhone transfer guide.
iPhone to Android
There is no direct Quick Transfer from iPhone to Android. Remove the eSIM from your iPhone (Settings > Cellular > select eSIM > Remove Cellular Plan), then scan your StarHub QR code on your new Android device.
Lost your QR code? Open the StarHub App > More > eSIM QR Manager to retrieve it. Request a re-send via email. If you no longer have access to either, contact StarHub's hotline or 24/7 LiveChat for a replacement.
How to Convert a Physical SIM to eSIM?
If you want to convert your physical SIM to an eSIM on StarHub, you have 2 options.
Option 1: Digital Channels
The fastest way to switch. Use the StarHub App or contact LiveChat.
- QR code sent via email instantly.
- Physical SIM deactivates automatically upon scanning.
- Zero conversion fees.
Option 2: StarHub Shop
Visit any StarHub shop and a staff member will process the switch for you.
- Face-to-face assistance.
- One-time SIM replacement charge applies.
eSIM Troubleshooting:
Common Issues and Fixes
Most eSIM activations go smoothly. When they do not, one of these issues is usually the cause.
Make sure you are connected to a stable WiFi network. Mobile data alone is sometimes insufficient for the initial download. Restart your phone and try scanning again. If the problem persists, confirm your phone's software is fully updated.
Open the StarHub App > More > eSIM QR Manager to retrieve your QR code. Request it to be re-sent to your email from the same screen. If you cannot access the app, contact StarHub's 24/7 LiveChat.
Suspend your eSIM immediately via the StarHub App > More > Report lost SIM. Alternatively, call our hotline or use 24/7 LiveChat. Once you have a replacement phone, request a new QR code to reactivate your line.
Unlike a physical SIM, an eSIM cannot be removed from a broken phone. Contact StarHub's hotline or LiveChat. We will verify your identity and issue a new QR code for your replacement device.
Ensure Bluetooth and WiFi are on for both devices. If Quick Transfer fails, try forgetting the Bluetooth pairing and reconnecting. As a fallback, delete the eSIM from the old phone and scan your StarHub QR code on the new device.
Frequently Asked Questions
An eSIM is a digital SIM chip built into your phone, receiving carrier information wirelessly. A regular SIM is a removable plastic card you insert into a tray. Both perform the same function: connecting your phone to a mobile network. The difference is in setup and management. eSIM is faster to activate, more secure, and supports multiple profiles on 1 device.
There are no charges when you choose eSIM for a new mobile plan or recontract from an existing StarHub mobile line to a new 5G mobile plan. Re-using your existing eSIM on another device is also free. A one-time charge of $11.90 applies only when you switch from a physical SIM to an eSIM at a StarHub shop. eSIM replacement (which includes switching from a physical to eSIM) is currently free when done via digital channels. StarHub recommends using the StarHub App for greater convenience.
Newer iPhones (iPhone 13 and later) store up to 8 eSIM profiles and allow 2 to be active simultaneously. Most Android phones support 1 to 2 eSIM profiles. You only need 1 active eSIM for your StarHub line, but the extra slots are useful for adding travel data plans or a second number.
No. Both eSIM and physical SIM use the same radio hardware and antenna. Battery consumption is identical. If you run 2 active lines simultaneously (dual SIM), your phone will use more battery than a single-line setup, but this applies equally to physical dual-SIM phones.
You need an internet connection (WiFi or mobile data) to download and activate an eSIM for the first time. Once activated, the eSIM connects to the mobile network like a physical SIM and does not need WiFi to make calls, send texts or use mobile data.
On most iPhones, you are given the option to keep or erase eSIMs during a factory reset. If you choose to erase, you will need to re-scan your QR code. On Android, a factory reset typically removes all eSIM profiles. Keep your StarHub QR code saved to reinstall your eSIM after resetting.
Where to Buy eSIM in Singapore?
eSIM is available for all StarHub mobile plans at no extra charge. Sign up online, scan your QR code, and connect to 5G in minutes. Travelling to Singapore? Grab a Traveler eSIM for instant 5G data from the moment you land.
Disclaimer:
This content is provided for general information and convenience. While we take care in preparing our articles, readers should refer to official sources or professional advice for specific, up-to-date details.
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