eSIM glossary

Plain-language definitions of the terms you meet when you buy and install a travel eSIM: EID, ICCID, SM-DP+, APN, carrier lock, top-up and more.

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4G / LTE: The fourth generation of mobile networks and the one most travel data plans use. LTE (Long-Term Evolution) is the name most phones show next to the signal bars. See also: 5G, Throttling
5G: The fifth generation of mobile networks, with higher peak speeds and lower delay than 4G where the local operator has built it. A plan can support 5G, but you only get it in areas the operator covers. See also: 4G / LTE

A

Activation code (manual installation code): The text that tells your phone which eSIM to download. It is inside the QR code, and you can also type it in by hand, together with the SM-DP+ address, when you cannot scan the code. See also: QR code, SM-DP+
Activation deadline: How long after buying you have to start using the eSIM. The days of the plan do not count down before it starts. See also: Validity
APN (Access Point Name): The internet setting a network uses to connect your phone to mobile data. Most eSIMs set it automatically; if one needs it typed in, the value is in the setup instructions. See also: Data roaming

C

Carrier lock (SIM lock): A restriction that ties a phone to one mobile operator. A locked phone may refuse an eSIM from another provider. The operator that sold the phone can unlock it; a phone bought unlocked is not affected. See also: eSIM

D

Daily plan: A plan that gives you a fresh amount of high-speed data each day. After you use it, you stay online at a lower speed until the next day. See also: Fixed plan, Fair use policy
Data allowance: The amount of mobile data a plan includes, for example 5 GB in total or 1 GB per day. See also: Fixed plan, Daily plan, GB and MB
Data roaming: A phone setting that lets a line use a partner network abroad. Travel eSIMs usually need it switched on for the eSIM line; you pay for your plan, not roaming fees, but keep it off for your home SIM if you want to avoid its roaming charges. See also: APN
Data-only eSIM: An eSIM that gives you mobile internet without a phone number. Keep your usual SIM for calls and texts; calling and messaging apps work over the data connection. See also: Dual SIM, eSIM
Dual SIM: A phone that can hold two lines at once, most often a physical SIM plus an eSIM, or two eSIMs on newer models. It lets you keep your home number for calls and texts while a travel eSIM carries the data. See also: eSIM, Physical SIM

E

EID (eUICC identifier): The unique number of the eSIM chip in a device, usually 32 digits. Providers may ask for it to check compatibility. Dial *#06# on most phones, or open the phone’s About or SIM settings, to see it; if an EID appears, the phone has an eSIM chip. See also: eUICC, IMEI
eSIM (embedded SIM): A SIM that is built into a device instead of being a removable card. You download a mobile plan onto it, usually by scanning a QR code, so you can buy and install a plan online without a shop or a plastic card. See also: eUICC, eSIM profile, Physical SIM
eSIM profile: The digital plan installed on the eSIM chip: it holds the operator’s network settings and credentials. A device can store several profiles, although usually only one or two are active at a time. See also: eSIM, LPA
eUICC (embedded universal integrated circuit card): The chip inside an eSIM-capable device that stores eSIM profiles. It is the hardware part of an eSIM, and it is what an EID identifies. See also: EID, eSIM

F

Fair use policy (FUP): A network rule that lowers the speed, or sometimes stops service, after a certain amount of data. It is common on plans described as unlimited, so everyone gets a good connection. See also: Throttling, Unlimited plan
Fixed plan: A plan with one total amount of data for its whole validity period, for example 10 GB for 30 days. Compare a daily plan, which renews its allowance each day. See also: Daily plan, Data allowance

G

GB and MB: Units of data. A gigabyte (GB) is about 1,000 megabytes (MB). Messaging and maps use a few MB an hour; HD video streaming can use a few GB an hour. See also: Data allowance

H

Hotspot (tethering): Sharing your phone’s mobile data with a laptop, tablet or another phone over Wi-Fi, USB or Bluetooth. Plans differ on whether they allow it. See also: Data allowance

I

ICCID (SIM serial number): The serial number of a SIM or eSIM profile, typically 18 to 22 digits. Support may ask for it to identify your eSIM. See also: eSIM profile
ID verification (KYC, know your customer): Some countries require an identity check before a mobile plan can be used. The plan details say when it applies. See also: Activation deadline
IMEI (International Mobile Equipment Identity): The 15-digit number that identifies a phone’s hardware; a dual-SIM phone has one for each SIM slot. It is used for compatibility checks and, in some countries, to register a foreign phone. Dial *#06# to see it. See also: EID
Internet location (IP location): The country that websites think you are connecting from. On some travel eSIMs it differs from where you are, and it does not limit where the plan works. See also: Data roaming

L

LPA (Local Profile Assistant): The part of your phone’s software that downloads and manages eSIM profiles. It is what runs when you scan an eSIM QR code. See also: eSIM profile, SM-DP+

M

Mbps (megabits per second): The unit for connection speed. About 1 Mbps is enough for messaging and maps, a few Mbps for standard video, and more for HD video and large downloads. See also: Throttling, 4G / LTE
MNO and MVNO (mobile network operator, mobile virtual network operator): A mobile network operator (MNO) owns the network. A mobile virtual network operator (MVNO) sells plans over an MNO’s network without owning it. An eSIM plan connects to an operator’s network either way. See also: Network operator

N

Network operator (carrier): The company whose mobile network your eSIM connects to in a country. A plan can list one or several operators, and which one you get can depend on where you are. See also: MNO and MVNO, 4G / LTE

P

Physical SIM (nano-SIM): The removable plastic SIM card that goes in a phone’s SIM tray. An eSIM does the same job without a card. See also: eSIM, Dual SIM
Prepaid: You pay for a plan before you use it. There is no contract, no monthly bill and no charge beyond what you bought. See also: Travel eSIM

Q

QR code: The square code you scan with your phone camera to install an eSIM. It holds the address of the operator’s server and your activation code. See also: Activation code, SM-DP+

R

Regional plan (multi-country plan): A plan that works in several countries with one eSIM, for example across a region. A global plan does the same across many regions. Coverage differs between plans, so check the country list. See also: Travel eSIM

S

SM-DP+ (Subscription Manager Data Preparation): The operator’s server that prepares your eSIM profile and delivers it to your phone. Its address is part of the QR code and of the manual installation details. See also: LPA, Activation code

T

Throttling (reduced speed): A deliberate drop in speed once you pass a data threshold, for example after your daily high-speed allowance. You stay connected, only slower. See also: Fair use policy, Daily plan
Top-up: Adding more data or days to the eSIM you already have, from your account, without a new QR code. Not every plan supports it. See also: Fixed plan
Travel eSIM: An eSIM data plan sold for use abroad, usually prepaid and covering one country or a region, so you do not depend on your home operator’s roaming prices. See also: eSIM, Prepaid, Regional plan

U

Unlimited plan: A plan without a fixed data total for its period. Most have a fair use policy, so speed drops after a threshold; the plan details state the rule. See also: Fair use policy, Throttling

V

Validity (plan length): How many days you can use the plan once it starts. Most plans start when the eSIM first connects at your destination, not when you buy it. See also: Activation deadline

New to eSIM? Start with how to choose a travel eSIM or the what is eSIM guide.