eSIM glossary
The words that show up while buying and installing, defined briefly here and in full on each term page.
4G LTE
Fourth-generation networking, still the practical standard for travellers.
5G
Fifth-generation mobile network technology.
Activation code
The code paired with the SM-DP+ address that authorises the profile download.
Activation time
The moment a plan's countdown begins.
APN
The access point setting a phone uses to route data.
Basic troubleshooting
The order of checks when an installed eSIM will not connect.
Carrier lock
A handset tied to the operator that sold it.
Coverage
Where a network actually reaches.
Coverage map
The map an operator publishes showing where it provides service.
Daily plan
A plan giving a data allowance per day that resets daily.
Data roaming
Using data on a network other than your home operator's.
Data usage
How much data different apps consume.
Data-only plan
A plan that provides internet only, with no number for calls or SMS.
Dual SIM
Using two lines in one phone at the same time.
EID
The identifier of the eSIM chip in your device.
eSIM
A SIM built into the phone, where the network profile is downloaded instead of inserted.
eSIM profile
The network credentials downloaded onto the eSIM chip.
eSIM transfer
Moving a profile to a new device.
eUICC
The chip inside the device that can hold several eSIM profiles.
Fixed data plan
A plan with one total data pool usable any time inside its validity.
Fulfilment
Everything between a successful payment and the profile reaching the buyer.
Full-speed allowance
The amount of data you get before the speed is reduced.
FUP fair usage policy
The rule that slows your speed after a stated amount of data.
Global plan
A plan covering many regions worldwide.
Hotspot
Sharing your phone's data with other devices.
Idempotency
The mechanism that stops a repeated request creating a duplicate order.
Identity registration
The requirement in some countries to register a SIM user.
IMEI
The unique identity number of a handset.
IMSI
The subscriber identity stored in a SIM profile.
Installation QR code
The image code used to download an eSIM profile onto a phone.
Line label
The name you give each line so you do not pick the wrong one.
Local breakout
Sending traffic to the internet in the visited country rather than routing it home.
MCC/MNC network code
The numeric code identifying a network's country and operator.
Network priority
The order in which a network allocates capacity between groups of users.
Network registration
The handshake where a phone asks a network for permission to attach.
Order reference
The code used to look up an order and trace a problem.
OTP code
The one-time code a bank sends by SMS.
Partner offer
A plan sold by another seller, where we may earn a referral fee.
Physical SIM
A SIM card you slot into a tray.
Physical SIM slot
The traditional card tray that many phones still carry.
Profile state
Whether a profile is downloaded, enabled, disabled or deleted.
Profile transfer
An operating-system feature that moves a profile to a new device.
Regional plan
One plan covering several countries in a region.
Roaming charge
What your home operator bills when you use a foreign network.
Roaming partner
The local operator your plan connects through.
SIM registration
A requirement in some countries to verify identity before a SIM works.
SM-DP+
The server address the phone contacts to download the profile.
Tethering
Another name for sharing phone data, over Wi-Fi, USB or Bluetooth.
Throttled speed
The speed that remains once the full-speed allowance is gone.
Throttling
Deliberately reducing speed once a threshold is passed.
Top-up
Adding more data to an existing profile without reinstalling.
Unlimited plan
A plan with no data cap, subject to fair use rules.
Validity
The number of days a plan works, counted from when it starts.
Voice and SMS
Calls and texts, which most travel eSIM plans do not include.
Wi-Fi calling
Calling on your normal number over the internet instead of the mobile network.