An eSIM is a GSMA-defined global specification that enables Remote SIM Provisioning (RSP) on mobile devices.
The term eSIM is commonly used to describe a SIM that is embedded (soldered) into a device. However, according to the GSMA definition, eSIM does not strictly refer to a physical form factor. Instead, it refers to a SIM system that supports remote provisioning using eUICC technology, regardless of whether the SIM is removable, embedded, or integrated.
According to the GSMA, an eSIM allows a device to:
- Store multiple operator profiles
- Download operator profiles remotely
- Switch between profiles over the air
- Activate one profile at a time without replacing a physical SIM
It is important to distinguish between:
- eSIM: A SIM system that includes eUICC capability and supports remote provisioning
- eUICC: The software capability that enables remote profile management
- Embedded SIM: A hardware form factor (typically MFF2) soldered onto the device
What is eUICC?
eUICC (Embedded Universal Integrated Circuit Card) is the technology defined by the GSMA that enables Remote SIM Provisioning.
It is the software capability inside a SIM that allows:
- Secure storage of multiple operator profiles
- Remote downloading of profiles
- Enabling and disabling profiles
- Deleting profiles
- Switching operators over the air
An eUICC-enabled SIM can exist in multiple form factors, including:
- Removable SIM cards (2FF, 3FF, 4FF)
- Embedded SIMs (MFF2)
- Integrated SIMs (iSIM)
While eUICC enables remote SIM provisioning through the GSMA standard, it isn’t the only path to multi-network flexibility. Some solutions use multi-IMSI technology combined with intelligent applets on the SIM to enable access to multiple networks and perform updates over the air, without relying on GSMA eUICC remote provisioning.
Understanding the GSMA SGP Specifications
The GSMA defines eSIM standards through the SGP series. These specifications determine how Remote SIM Provisioning works in consumer and IoT devices.
SGP.02- M2M eSIM
SGP.02 was the original specification for M2M (machine-to-machine) deployments. It used a push model, where mobile network operators controlled profile provisioning and switching.
While effective for early M2M use cases, it limited enterprise flexibility and required complex operator coordination, reducing autonomy for large-scale IoT deployments.
SGP.22 – Consumer eSIM
SGP.22 defines the consumer eSIM architecture used in smartphones, tablets, and wearables.
It enables users to download and switch operator profiles remotely, but relies on user interaction and device interfaces. This makes it practical for consumer devices, but less suitable for IoT devices without screens or input capabilities.
SGP.32 – IoT eSIM
To address these limitations, the GSMA introduced SGP.32, a new architecture purpose-built for IoT deployments in low-touch, low-power environments.
It introduces two core components:
- IoT Profile Assistant (IPA) – Software embedded in the device (IPAd) or eUICC (IPAe) that enables automated profile management.
- eSIM IoT Remote Manager (eIM) – A cloud-based control layer that issues profile management commands and interfaces with provisioning platforms such as SM-DP+.
Together, these components enable more flexible, scalable, and autonomous IoT connectivity.
What Is an Embedded SIM?
An embedded SIM refers specifically to a hardware form factor. The most common embedded format is MFF2, which is soldered directly onto a device’s circuit board during manufacturing. Unlike removable SIM cards, it cannot be physically replaced.
An embedded SIM:
- Is permanently integrated into the device
- Is more resistant to vibration, dust, and temperature extremes
- Is commonly used in industrial and IoT deployments
Importantly, an embedded SIM may or may not support eUICC.
- If it includes eUICC functionality, it can support remote provisioning.
- If it does not, it behaves like a traditional SIM tied to a single operator, unless it is using another technology called multi-IMSI.
eSIM vs eUICC vs Embedded SIM Summary
eUICC: The GSMA-developed software capability that enables Remote SIM Provisioning (RSP). When embedded in a SIM, it allows multiple subscription profiles to be stored and managed remotely. eUICC can be present across multiple SIM form factors.
eSIM: According to the official GSMA definition, an eSIM is any SIM, regardless of form factor, that supports remote reprogramming using eUICC technology.
Embedded SIM: A SIM form factor that is permanently soldered onto a device (typically MFF2). An embedded SIM may or may not include eUICC capabilities.
Velocity IoT offers eUICC-enabled and multi-IMSI SIM solutions, providing flexible remote profile management and intelligent network access within a single SIM strategy.
Through localized connectivity, low-latency global routing, and robust security architecture, Velocity IoT enables businesses to simplify global deployments while maintaining control, resilience, and long-term scalability.