What Are APN, IMEI and ICCID? A Simple eSIM Glossary
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In one line each: the APN is the setting that tells your phone how to connect to mobile internet, the IMEI is the unique ID of the phone itself, and the ICCID is the unique ID of the SIM card or eSIM profile installed on it. Dial *#06# to see your IMEI on any phone.
Whenever you deal with an eSIM, a few technical terms come up that sound complicated but are actually simple: APN, IMEI and ICCID. They appear again and again in installation instructions, support requests and phone settings. In this guide we explain each one in plain language, including how and when you'll actually need it.
APN: the address for mobile internet
What it is
APN (Access Point Name) is the setting that tells your phone "which route to take to the internet" on the provider's mobile network. Think of it as an internal address the phone needs in order to turn mobile signal into actual data.
When you'll come across it
Usually the APN is set automatically as soon as you scan the eSIM's QR code, and you never need to touch it. But if you have full signal and still no data, it's almost always a sign of an APN problem, and then you need to enter it manually in your phone's settings according to the provider's instructions. Here's how to set up the APN on iPhone and Android.
Where to find it
The relevant APN details usually come in your eSIM installation email, or in the provider's customer portal.
IMEI: the phone's own ID card
What it is
IMEI (International Mobile Equipment Identity) is a unique identification number for the phone itself, not for the SIM card. Every phone in the world has a different IMEI, just like a car's chassis number. It stays the same even if you swap SIM cards or install several different eSIM profiles.
When you'll need it
- Checking eSIM support: some manufacturers and providers ask for your IMEI to confirm that your phone supports eSIM and isn't locked to a specific carrier
- Reporting theft or loss: if your phone is stolen, the IMEI is what allows it to be blocked on mobile networks around the world
- Contacting technical support: sometimes your eSIM provider will ask for the IMEI to identify compatibility issues specific to your model
How to find it
- On any phone: dial *#06# and your IMEI appears on screen immediately
- iPhone: Settings → General → About, then scroll down to IMEI
- Android: Settings → About phone → Status → IMEI information
Note: phones with two physical SIM slots or Dual eSIM support sometimes show two IMEI numbers, one for each virtual "slot".
ICCID: the ID of the SIM card (or eSIM profile)
What it is
ICCID (Integrated Circuit Card Identifier) is the unique number that identifies the SIM card itself, whether physical or digital. While the IMEI identifies the phone, the ICCID identifies the specific line installed on it, including every eSIM profile you've bought.
An ICCID is usually long (18 to 22 digits), and every eSIM profile you install gets its own unique ICCID.
When you'll need it
- Tracking an order: many eSIM providers use the ICCID to identify which order belongs to you, especially if you have several active eSIMs
- Contacting support: when you report a problem, the ICCID is the fastest way for the provider to find your specific profile and check its status
- Checking remaining data: some systems need the ICCID to show how much data you have left. With FlySim you can check your usage here.
How to find it
- iPhone: Settings → General → About, then scroll to the relevant eSIM line to see the ICCID
- Android: Settings → SIM cards → choose the eSIM profile → SIM card details
- In your installation email: in most cases the ICCID also appears in the purchase confirmation email from your provider
Quick comparison table
| Term | What it identifies | When you'll need it |
|---|---|---|
| APN | The setting for mobile internet access | When you have signal but no data |
| IMEI | The physical phone itself | Checking eSIM compatibility, reporting loss or theft |
| ICCID | The specific SIM or eSIM profile | Contacting support, checking remaining data |
Frequently asked questions
Are IMEI and ICCID the same thing?
No. The IMEI identifies the phone itself and stays fixed for its whole life, while the ICCID identifies a specific SIM card or eSIM profile, and changes every time you install a new profile.
Does my IMEI change when I install a new eSIM?
No. The IMEI always stays the same because it belongs to the phone, not the SIM card. Only the ICCID changes with each new installation.
How do I send my ICCID if support asks for it?
Usually by taking a screenshot of the settings screen that shows the details, or by copying the number from the screen straight into your message to support.
Can I tell whether a phone supports eSIM just from its IMEI?
Usually not without dedicated tools, but manufacturers and carriers use it to check compatibility against their database of supported models. The simpler way is our eSIM compatibility checker.
Summary
APN, IMEI and ICCID look similar at first glance but do completely different jobs: the APN is the internet access setting, the IMEI identifies the phone itself, and the ICCID identifies the specific line or eSIM profile. A basic understanding of the differences makes every support request, and every future installation, much simpler and faster.