eSIM Glossary: Key Terms and Definitions
Complete glossary of eSIM terminology. Understand technical terms like eUICC, SM-DP+, ICCID, remote provisioning, and more.
eSIM Glossary
A comprehensive glossary of terms related to eSIM technology and mobile connectivity. Bookmark this page for quick reference.
A
APN (Access Point Name)
A gateway between a mobile network and the internet. When setting up an eSIM, the correct APN is usually configured automatically by the carrier profile.
Activation Code
A unique code provided by your eSIM provider used to download and activate your eSIM profile. Usually embedded in a QR code.
C
Carrier
A mobile network operator (MNO) that provides cellular service. Examples include AT&T, Vodafone, T-Mobile, and NTT Docomo.
Carrier Lock
A restriction placed by a carrier that prevents a device from being used with other carriers. Your phone must be carrier-unlocked to use a third-party eSIM. See our activation guide for details.
D
Data Roaming
Using cellular data outside your carrier’s home network. Travel eSIMs eliminate expensive roaming by providing local data access. Learn about travel eSIM.
Dual SIM
A device capability that allows two SIM profiles to be active simultaneously — for example, one physical SIM and one eSIM.
E
eSIM (Embedded SIM)
A SIM chip permanently built into a device that can be programmed remotely with carrier profiles. What is eSIM?
eUICC (Embedded Universal Integrated Circuit Card)
The physical chip inside an eSIM-compatible device that securely stores carrier profiles. It’s the hardware component that makes eSIM possible.
G
GSMA (GSM Association)
The industry body that sets standards for mobile communications, including eSIM specifications (SGP.22 standard).
I
ICCID (Integrated Circuit Card Identifier)
A unique serial number assigned to each SIM profile. For eSIM, each downloaded profile has its own ICCID.
IMEI (International Mobile Equipment Identity)
A unique 15-digit number identifying your device. Some eSIM providers require your IMEI during purchase to ensure compatibility.
L
LPA (Local Profile Assistant)
Software on your device that manages eSIM profiles — downloading, enabling, disabling, and deleting carrier profiles.
M
MNO (Mobile Network Operator)
A company that owns and operates a cellular network (e.g., Verizon, Orange, SK Telecom). Distinguished from MVNOs which lease network capacity.
MVNO (Mobile Virtual Network Operator)
A carrier that doesn’t own network infrastructure but leases capacity from MNOs. Many eSIM travel providers operate as MVNOs.
N
Nano SIM
The smallest physical SIM card format (12.3mm x 8.8mm), used in most modern smartphones alongside eSIM support.
P
Profile
A set of carrier credentials and settings stored on the eUICC. Each eSIM profile represents a connection to a specific carrier and plan.
Provisioning
The process of downloading and installing a carrier profile onto an eSIM. Also called “remote SIM provisioning.”
Q
QR Code Activation
The most common method of eSIM activation where you scan a QR code containing the server address and activation credentials.
R
Remote SIM Provisioning (RSP)
The technology that allows carrier profiles to be downloaded over the internet to an eSIM device, eliminating the need for physical SIM cards.
Roaming
Using your mobile service outside your carrier’s primary coverage area. Traditional roaming can be expensive — eSIM offers a cost-effective alternative. Compare plans.
S
SGP.22
The GSMA technical specification for consumer eSIM remote provisioning. It defines how eSIM profiles are created, downloaded, and managed.
SM-DP+ (Subscription Manager Data Preparation)
A server that prepares and delivers eSIM profiles to devices. When you activate an eSIM, your device connects to the SM-DP+ to download the profile.
SM-DS (Subscription Manager Discovery Server)
A server that helps devices discover which SM-DP+ server holds their eSIM profile. Acts as a directory service.
SIM Swap
A security attack where a criminal convinces a carrier to transfer your number to their SIM. eSIM technology helps prevent this type of fraud.
T
Top-Up
Adding more data or extending the validity of an existing eSIM plan, usually through the provider’s app.
V
VoLTE (Voice over LTE)
Technology that allows voice calls over a 4G/LTE network. Some eSIM plans support VoLTE, enabling HD voice calls.
Learn More
Where can I learn more about eSIM?
Start with our beginner’s guide to eSIM, then explore our setup guides and travel tips.
How do I check my device compatibility?
Visit our device compatibility checker to see if your phone supports eSIM.
Where can I compare eSIM providers?
Use our comparison tool to find the best eSIM plans for your destination.