What is the difference between eUICC and eSIM?
eUICC is the secure hardware element that stores and manages subscription profiles. eSIM is the broader system combining eUICC hardware, carrier profiles, remote provisioning infrastructure, and device software. When you "activate an eSIM," you're downloading a profile onto the eUICC.
Related FAQs
What does eUICC stand for?
eUICC stands for embedded Universal Integrated Circuit Card—a UICC with GSMA Remote SIM Provisioning (RSP) that enables multiple carrier profiles to be managed remotely.
Is eUICC always soldered or embedded?
No, eUICC can be embedded (MFF2) or removable (2FF, 3FF, 4FF sizes). The defining feature is Remote SIM Provisioning capability, not physical form factor.
How many profiles can an eUICC store?
eUICC profile capacity varies by memory size, profile complexity, and device policy. There's no fixed industry number—it depends on specific device and vendor implementation.
What is MFF2?
MFF2 (Machine Form Factor 2) is the standard embedded eUICC form factor at 5×6×0.75mm, soldered to device circuit boards. Defined by ETSI TS 102 671.
What is the difference between eUICC and iSIM?
eUICC is a discrete secure element chip. iSIM integrates SIM functionality directly into the device processor or modem, eliminating the separate chip. Both support remote provisioning.
Can eUICC switch between carriers automatically?
Yes, eUICC can download new profiles and switch carriers remotely with proper provisioning infrastructure. IoT deployments using SGP.32 automate this for entire device fleets.
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