1. What makes a SIM an "eUICC"?
The term eUICC (Embedded Universal Integrated Circuit Card) refers to the software and hardware architecture that supports Remote SIM Provisioning (RSP).
While the "e" stands for embedded, it is a common industry misconception that these must be soldered chips. An eUICC is simply a "Smart SIM" that can host multiple network profiles and download new ones over-the-air (OTA) using a “Subscription Manager” (SGP.02) or a “Fleet Manager” (SGP.32).
2. Form Factors:
An eUICC can be delivered in any physical format:
- Removable Plastic (2FF/3FF/4FF): A standard "triple-cut" card that looks like a traditional SIM but possesses eUICC logic. Allowing devices with standard SIM slots to utilise remote provisioning technology.
- MFF2 (Soldered): The tiny 5x6mm chip soldered directly to the motherboard, typical in iPhones and industrial trackers.
3. Key Operational Differences
When a device uses an eUICC instead of a standard SIM, it must handle these tasks differently:
- Bootstrap Profile: The device uses a "pre-installed" profile just to get enough data to talk to our servers and download its "operational" (final) profile.
- The LPA (Local Profile Assistant): The device needs software logic (the LPA) to manage the download, installation, and switching of these digital profiles.
- Network Re-registration: Unlike a physical swap, the modem must be told to "refresh" and find the new network once a digital profile is toggled.
4. Compatibility Checklist
Not every device can handle the RSP protocol. Use these steps to verify:
- Check for the EID: If the device displays an Embedded Identity Document (EID) in Settings > About, it is eUICC-ready.
- Dial *#06#: If an EID barcode appears on the screen, the hardware is compatible.
- Carrier Lock Status: A device may have the hardware, but if it is "Locked" to a specific provider, the eUICC will be blocked from downloading our profiles.