eSIM and roaming glossary for travellers from India
The SIM ICCID number names one SIM card or one eSIM profile. The IMEI identifies the phone, and the EID identifies the eSIM chip inside it. The roaming and plan terms further down carry Jio and 
Airtel examples as listed on 12 Oct 2026.
Give support the number that matches the problem. The SIM ICCID number points to a plan that will not connect, the IMEI to a locked or lost phone, and the EID to the eSIM chip itself. Your Indian SIM’s ICCID never helps with a travel eSIM ticket, because each eSIM profile has its own.
| Term | What it identifies or means | Where it matters |
|---|---|---|
| ICCID | One SIM card or one eSIM profile | A support ticket about a plan |
| IMEI | One phone (two on a dual-SIM phone) | Lost-phone reports, blocked handsets |
| EID | The eSIM chip in the phone | Whether a phone can take an eSIM |
| Data roaming | Using mobile data on a foreign network | A setting you switch per line |
| FUP | The data threshold after which speed drops | Reading any “unlimited” claim |
We sell travel eSIMs, so we have an interest here. The definitions follow the operators’ own pages and the Department of Telecommunications, and they hold whichever seller you use. eSIM Go is not affiliated with Jio, Airtel, Vi or BSNL. Pack details are taken from their own pages on the date shown.
Numbers that identify your SIM and phone: ICCID, IMEI, EID
An ICCID identifies a SIM or eSIM profile, an IMEI identifies the phone, and an EID identifies the eSIM chip. Support asks for the one that matches your problem. Your phone lists them in its settings: on an iPhone, Apple shows the IMEI and ICCID under Settings, General, About.
ICCID
The ICCID (integrated circuit card identifier), also called the SIM ICCID number, is the serial number of one SIM card or one eSIM profile. A physical SIM has it printed on the card. A downloaded eSIM profile has its own ICCID, different from the one on your Indian SIM. Guides online give lengths from 18 to 22 digits, so copy the whole number from your settings instead of counting.
If one of our eSIMs does not connect, send support the SIM ICCID number of that line, so we know which profile you mean. Your Indian SIM’s ICCID is a different number and does not help with that ticket. How to install an eSIM shows where the profile appears in your phone’s settings.
IMEI
The IMEI (international mobile equipment identity) is a 15-digit number that identifies the phone itself, not the SIM. Dial *#06# to see it. The Department of Telecommunications notes that a dual-SIM phone has two IMEI numbers, one per SIM slot.
The IMEI belongs to the handset, so it stays the same when you put in another SIM or install an eSIM. Indian networks check it against the DoT’s Central Equipment Identity Register (CEIR), which is how a lost or stolen phone gets blocked. You need it when you report a lost phone.
EID
The EID (eUICC identifier) is the number of the eSIM chip inside the phone. The chip has it whether or not you have installed a plan, and one chip can hold several eSIM profiles. A phone without an eSIM chip has no EID. The list of eSIM phones shows which models have the chip.
eSIM terms: eSIM profile, activation code
An eSIM profile is the downloadable plan that lives on your phone’s eSIM chip, and the activation code is what you scan to download it. A profile does nothing until the phone connects to a network. Install the eSIM in India; it connects when you land abroad.
eSIM
An eSIM is a SIM built into the phone: you add plans by download instead of inserting a card. What is an eSIM explains how it sits next to your Indian SIM.
eSIM profile
An eSIM profile is a software copy of a SIM: it holds the plan, the network settings and its own ICCID. Phones store several profiles, but usually only one or two are active at a time, depending on the model. You can turn a profile off without deleting it. Deleting it removes the plan from the phone, and a deleted profile usually cannot be installed again from the same code.
Our travel eSIM profile carries data only and has no Indian number. Your Indian SIM stays in the phone next to it.
Activation code
The activation code is the text or QR code that tells your phone where to download the profile: it contains the SM-DP+ address (the server that holds the profile) and a matching ID. How to install an eSIM covers the QR and the manual install step by step.
Roaming terms: data roaming, international roaming, IR pack, in-flight pack
Data roaming means your phone uses mobile data on a network that is not your home operator’s. With two lines in the phone, switch it on for the travel eSIM and off for your Indian SIM. Your operator’s alternative is an IR pack. The examples below are as listed on 12 Oct 2026.
Data roaming
Data roaming is the phone setting that allows mobile data on a foreign network. When it is off, that line gets no mobile data abroad.
The setting is per line on a dual-SIM phone. On a trip, set it on for the eSIM line and off for the Indian line. Then choose the eSIM as the line for mobile data. The Indian line can still take calls and SMS if roaming is active on it, without using data. Airtel adds a barrier of its own: its prepaid terms block data once a pack ends. Calls then cost ₹10 a minute and SMS ₹5 each. Keeping your Indian SIM for OTPs walks through the setup.
International roaming
International roaming is your Indian number working on a foreign network, usually through an operator pack. Jio sells the same roaming packs to prepaid and postpaid customers, while Airtel and Vi price their postpaid packs separately. International roaming from India has the full picture.
IR pack
An IR pack is an operator’s prepaid or postpaid bundle for use abroad: a set number of days and GB, and on most packs minutes and SMS. Airtel’s prepaid ₹998 pack gives 4 GB for 5 days, plus 150 minutes and 20 SMS, per Airtel’s terms dated 24 Sep 2026. That is about ₹250 per GB (our derivation, price ÷ GB).
Validity starts at different moments. Jio states: “Your plan validity begins only with your first usage—call, text, or data.” Compare packs on Airtel roaming and Jio roaming.
In-flight pack
An in-flight pack is a short roaming pack that works on board partner airlines. Jio’s packs cost ₹195, ₹295 or ₹595 for 1 day, with 250 MB, 500 MB or 1 GB. Jio notes that service “will differ from airline to airline”. Airtel’s start at ₹196 for prepaid (₹195 postpaid) for 24 hours and 250 MB, on partner airlines through AeroMobile.
Our travel eSIM does not work in the air; it connects after you land. More on in-flight packs.
Plan terms: data-only plan, FUP
A data-only plan carries mobile data and nothing else: no calls, no SMS and no phone number. A FUP is the fair usage threshold after which speed drops, and Jio prints 64 kbps as that speed on its IR data packs. Both decide what a plan can and cannot do for you abroad.
Data-only plan
A data-only plan gives you internet and no voice or SMS service. WhatsApp calls use the plan’s data, but bank OTPs arrive by SMS on your Indian number, so keep your Indian SIM in the phone. Our travel eSIMs carry data only, unless a plan page says otherwise.
FUP
FUP stands for fair usage policy: the threshold after which a plan slows down instead of stopping. Jio lists 64 kbps beyond the FUP on its Saudi Arabia packs and its IR data packs. For example, ₹599 buys 1 GB for 7 days, then 64 kbps. Jio’s US, Mexico and Canada pack at ₹1,555 gives 12 GB over 15 days, then up to 64 kbps.
Airtel’s ₹2,999 postpaid pack is sold as unlimited for 10 days: 10 GB at high speed, then 80 kbps. It applies across India except the Maharashtra circle, per Airtel’s terms dated 24 Sep 2026. At 64 or 80 kbps, maps and messages load slowly and video does not stream. Read “unlimited” as “unlimited until the FUP”, and look for the threshold in the same line.
Phone settings and safety: APN, Wi-Fi calling, SIM swap
An APN is the setting your phone uses to reach mobile data, Wi-Fi calling carries calls over Wi-Fi, and a SIM swap is a fraud that moves your number to someone else’s SIM. The first two decide whether data and calls work abroad. The third concerns your Indian number, not the travel eSIM.
APN
An APN (access point name) is the network setting that tells your phone how to reach the mobile data network. Most travel eSIMs set it automatically; when one of our plans needs it typed in, the plan details give the value. Phone-by-phone steps are in the APN settings guide.
Wi-Fi calling
Wi-Fi calling sends voice calls and SMS over a Wi-Fi network instead of the mobile network. Your phone and your operator both have to support it. Jio sells Wi-Fi calling packs for calls to India: ₹121 for 100 minutes and ₹521 for 500 minutes, each listed for 10 days.
For the ₹121 pack, the plan filter on Jio’s page shows 2 days instead, so confirm in the MyJio app. A data-only travel eSIM has no phone number, so Wi-Fi calling belongs to your Indian line.
SIM swap
A SIM swap is when a fraudster gets an operator to move your number to a SIM they hold, so your calls and OTP messages reach them instead of you. A travel eSIM does not touch your Indian number: it is a separate data profile, and your Indian SIM stays in the phone. The OTP guide explains how to keep that line active abroad, and no page can promise that every OTP will reach you.
Sources checked: Jio IR plans (in-flight packs, IR data packs, Saudi Arabia packs, US Mexico and Canada pack, Wi-Fi calling packs, validity rule) · Airtel IR terms, dated 24 Sep 2026 (prepaid ₹998 pack, postpaid ₹2,999 pack, in-flight packs, charges after the pack) · Central Equipment Identity Register (CEIR), Department of Telecommunications (IMEI length, one IMEI per SIM slot, *#06#, blocking lost or stolen phones) · Apple Support: find the serial number, EID or IMEI on your iPhone (where an iPhone lists the IMEI and ICCID) · Editor: Nadezhda Semenova. See our editorial policy. Last checked 12 Oct 2026.