An eSIM is a SIM card delivered as software instead of a piece of plastic. Instead of inserting a physical SIM, you download a profile to the device, and the device's built-in eUICC chip stores it. From there it acts like any other SIM, the only difference is how it got there.
eSIM vs. eUICC: they're not the same thing
People use the terms interchangeably, but they describe two different layers:
eUICC The hardware: an embedded chip on the device that's capable of holding and switching between SIM profiles.
eSIM The profile: a downloadable file that gets installed onto an eUICC chip.
A device needs an eUICC to use an eSIM. Most modern smartphones, tablets, and IoT cellular modules ship with eUICC capability built in. Whether they accept only eSIMs (no plastic SIM tray) or both is up to the device manufacturer.
What's in an eSIM "download"
When you install a Simbase eSIM, the device fetches three things from a remote server, the SM-DP+ (Subscription Manager Data Preparation Plus):
The IMSI and authentication keys (the same secrets a plastic SIM stores).
The operator profile (network preferences, APN configuration).
Optionally, profile metadata (name, icon, switching rules).
Once installed, the eSIM is a fully functional SIM. The device authenticates to the network using it just as it would with a plastic card.
When eSIM is the right choice
Pick eSIM over a plastic SIM when:
The device is sealed. No SIM tray, no SIM swap. Common in industrial sensors, asset trackers, vehicle telematics, and consumer IoT.
You can't physically reach the device. A device in a remote location, deployed at a customer site, or already in the field can be re-provisioned over the air.
You manage a large fleet. Provisioning thousands of plastic SIMs at scale (handling, ICCID matching, shipping) is operationally painful. eSIM makes it a server-side operation.
The device travels between countries. With eUICC, you can switch the operator profile to a regional one OTA when the device crosses borders, instead of physically replacing SIMs.
You want to defer the connectivity decision. Manufacture the device, ship it, then decide which network operator's profile to install when it activates.
How Simbase delivers eSIMs
Simbase ships eSIMs as profiles you install from your dashboard. Each eSIM gets:
A QR code for devices that can scan one (most phones).
An SM-DP+ address and activation code for devices that can't scan QR (most IoT modules).
There is no confirmation code, leave that field blank if your device asks for one.
To activate, see Activate a Simbase eSIM.
eSIM and SIM profiles
Two different things share the "e" prefix, and they map to different profiles.
eSIM profiles (installed from a QR code or SM-DP+ address) are issued as Black or Green. The profile is bound to the device it's installed on.
eUICC SIM cards are physical SIMs with an eUICC chip, available as Blue or Yellow (ICCID 89445*). These support remote SIM provisioning: the operator credentials on the card can be updated over the air without touching the device.
See SIM profiles for coverage and pricing per profile, and Multi-IMSI vs eUICC for the technology difference.
Common questions
No. Simbase eSIM profiles are issued as Black or Green and stay bound to the device they're installed on. To connect a different device, order a new eSIM.
It needs an eUICC chip. Most smartphones, tablets, and modern IoT cellular modules have one. On phones, look for "Add eSIM" or "Add Data Plan" in mobile network settings. For IoT modules, check the datasheet for eSIM or eUICC support.
No, an eSIM costs less to buy than a single plastic SIM. That's the one-off cost of the SIM itself; connectivity is billed the same either way, since data rates and the daily fee follow the SIM profile, not the form factor.
It's the address of the server your device contacts to download the eSIM profile. You'll find it on the eSIM's detail page in your dashboard, alongside the activation code. Only needed for manual installs; scanning the QR code supplies it automatically.
Related
Activate a Simbase eSIM, installation instructions
Multi-IMSI vs eUICC, the technology trade-off
SIM Profiles, the different profiles Simbase uses
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