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.
In This Guide
- What is an eSIM and how is it different from a physical SIM?
- How does an eSIM work step by step?
- eSIM vs physical SIM: the real differences for you
- How to check if your phone supports eSIM
- How to activate and use your StarHub eSIM
- How to remove an eSIM from your phone
- Transferring your eSIM to a new phone
An eSIM is a digital SIM card built into your phone. No plastic card, no slot, no swapping.
You activate it by scanning a QR code, and it works exactly like a regular SIM once it's live. This guide explains how eSIM works, whether your phone supports it, and how to activate, use, and remove it on StarHub.
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 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
Both a physical SIM and an eSIM connect your phone to a mobile network. While they provide the same signal performance, the difference lies in hardware and management.
Whether you prefer a tangible card or a digital-first profile, integration is the key to staying connected.
Physical SIM
A removable card that slots into your device. Easy to swap between phones manually.
eSIM
A built-in digital chip. Store multiple profiles and switch plans via a QR code or app.
Performance is identical on both. The differences are all in how you manage them:
How to Convert a Physical SIM to eSIM?
Switching your current StarHub physical SIM to an eSIM is simple:
Option 1: Digital Channels
FREE
The fastest way to switch using the StarHub App or LiveChat.
- QR code sent via email instantly.
- Zero conversion fees.
Option 2: StarHub Shop
$11.90
Visit any StarHub shop and our staff will process the switch for you.
- Face-to-face assistance.
- One-time SIM replacement charge applies.
💡 Can You Have Both?
Yes. Most modern phones support Dual SIM functionality, allowing you to use a physical SIM and an eSIM simultaneously. This is perfect for keeping your work and personal numbers separate on one device.
How to Check If Your
Phone Supports eSIM?
Not every phone has eSIM hardware. Before making the switch, confirm your device is compatible using one of these 3 quick methods.
Method 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.
Method 2: Check Your Phone Settings
iPhone
Settings > Cellular > Add eSIM. If this option appears, your iPhone is compatible.
Android
Settings > Connections > SIM Manager. Look for an Add eSIM or Plus (+) icon.
Method 3: Carrier Lock Status
Your phone must be unlocked. On iPhone, check Settings > General > About > Carrier Lock. It should say "No SIM restrictions." For Android, contact your carrier to confirm.
eSIM-Compatible Devices (2026)
Upgrading soon? eSIM support is now standard on most mid-range and flagship models. Some newer devices have even removed the physical SIM tray entirely.
Frequently Asked Questions
Most StarHub eSIMs activate within 2 to 5 minutes of scanning the QR code. If you're porting your number from another carrier, the port itself takes up to a few hours. Your existing service stays live until it's complete, so you won't lose coverage during the switch.
Before you delete, know the difference: deleting permanently removes the eSIM profile and requires a new QR code from StarHub to reinstall. Deactivating (turning the line off in settings) pauses it without removing it, so you can switch it back on anytime. If you only want to stop using the eSIM temporarily, deactivate rather than delete. On iPhone, go to Settings → Cellular, tap the eSIM, and toggle "Turn On This Line" off. On Android, go to Settings → Connections → SIM Manager and toggle the eSIM off.
Yes. Most eSIM-compatible phones support dual SIM, so both run simultaneously. A common setup: personal number on the physical SIM, work or travel number on the eSIM. You can designate one as the primary for calls and data while keeping the other active for SMS and incoming calls.
Because the eSIM is embedded in the device, it cannot be physically removed and used in another phone. Contact StarHub immediately to suspend the line. Once you have a replacement device, StarHub can reissue your QR code so you can get back online.
No. Deleting the eSIM profile from your phone removes it from your device, but your StarHub plan stays active. If you want to end your plan, you need to contact StarHub separately. If you have an active data package, it's worth waiting until it expires before deleting.
Yes. The eUICC chip is encrypted and physically embedded in your phone. It cannot be removed or cloned the way a physical SIM can. If your phone is stolen, the number stays locked to the device until StarHub suspends it remotely. eSIM in Singapore operates under the same regulatory standards as physical SIM, governed by IMDA.
On iPhone, you're given the option to keep or erase your eSIM during a factory reset. Choose to keep it unless you're handing the phone to someone else. On Android, a factory reset typically removes all eSIM profiles. Either way, keep your StarHub QR code saved to your email before you reset, so you can reinstall easily.
Yes. Request a SIM replacement through the StarHub App under More → SIM Replacement. Switching via digital channels is currently free. A one-time charge of $11.90 applies if you switch at a StarHub shop. [VERIFY current fee before publishing]
eSIM is available on all StarHub 5G Unlimited+ mobile plans at no extra charge. Select eSIM at checkout when you sign up online, or upgrade via the StarHub App if you're already on a StarHub plan. [VERIFY availability and digital upgrade path before publishing]
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.
Related Articles
SIM Only Plan Comparison Singapore [2026]
