Priya Sharma
Travel Tech Writer
Quick Answer
Keep your Jio/Airtel SIM in the physical slot (receives OTPs and calls for free) and add a travel eSIM for local data. Enable WiFi Calling on your Indian SIM before departure — calls then route over the eSIM's internet connection at zero cost. SMS OTPs always work on your Indian SIM abroad without any data plan.
India's digital infrastructure is deeply tied to your mobile number. When you're abroad, losing access to your Indian number means:
The old solution was to keep your Indian SIM in the phone and pay international roaming rates. The new solution is eSIM + Dual SIM — keep your Indian physical SIM active while an eSIM handles local data.
If your phone supports eSIM (iPhone XS+, Samsung S20+, Pixel 3+, OnePlus 11+), this is the best approach:
Result: Your Indian number is fully active (calls, SMS, OTPs), and you have fast local data via eSIM — at a fraction of roaming cost.
Enable Data Roaming on your Indian SIM OFF — turn this off to avoid accidental roaming charges. Your Indian SIM only needs to receive SMS/calls, not data.
WiFi Calling (VoWiFi) lets your Indian SIM receive calls over an internet connection instead of cellular. This is crucial when abroad because:
Enable WiFi Calling on Jio: Settings → Mobile Data (Jio SIM) → WiFi Calling → Enable. Or open MyJio app → Profile → WiFi Calling.
Enable WiFi Calling on Airtel: Settings → SIM & Mobile Data (Airtel SIM) → WiFi Calling → Enable. Or Airtel Thanks app → More → WiFi Calling.
Once enabled, when you're abroad on WiFi or eSIM data, incoming calls to your Indian number route through internet — completely free.
International roaming from Indian carriers is expensive and often slow. Here's the comparison for Japan:
| Option | 7-day cost | Data |
|---|---|---|
| Jio International Pack (Japan) | ₹4,999 | 1 GB/day |
| Airtel International Pack (Japan) | ₹3,999 | 1 GB/day capped |
| Trovio eSIM (Japan) + WiFi Calling | ₹1,399 | 5 GB, 5G speed |
Recommendation: Don't activate roaming for data. Use eSIM for data. Optionally add Jio/Airtel's cheapest "incoming only" pack if you don't want WiFi Calling setup — but most travelers find WiFi Calling works perfectly.
Even without activating a roaming pack, Jio and Airtel charge for incoming international calls if your SIM is roaming. To avoid this:
Option A (best): WiFi Calling — enable WiFi Calling before you leave India. Calls route over internet, zero roaming charges.
Option B: Jio ISD pack — Jio offers an ₹75/day "Basic Roaming" add-on that covers incoming calls for up to 100 minutes/day. Cheap insurance if WiFi Calling doesn't work reliably at your destination.
Option C: Forward to WhatsApp — tell family to reach you on WhatsApp. Works globally over eSIM data, no charges.
Option D: Turn off data roaming on Indian SIM entirely — your SIM won't connect to any network abroad, no charges at all. You'll still receive SMS OTPs when you're on WiFi (SMS over WiFi/eSIM via some carrier apps) or when you briefly turn on roaming just to receive an OTP.
OTPs are the trickiest part of Indian travel connectivity. Here's how to handle the main scenarios:
Bank OTPs (HDFC, ICICI, SBI etc.): With Dual SIM + WiFi Calling enabled, SMS OTPs arrive normally. The SMS doesn't use data — it comes through on your Indian SIM just like at home. If you turned off data roaming on the Indian SIM, SMS still works (SMS doesn't require a data plan).
UPI (PhonePe, GPay, Paytm): UPI OTPs are SMS-based and work fine. However, some UPI apps verify your number at login using a silent SMS — this may fail if your SIM has zero signal. Pre-login to all UPI apps before you leave India.
WhatsApp: WhatsApp OTP is SMS-based. If you're setting up WhatsApp on a new device abroad, you'll need SMS access to your Indian number. With Dual SIM setup, this works. Alternatively, use WhatsApp Web from your laptop.
Aadhaar OTP: Aadhaar OTPs are SMS to your registered mobile. Same as bank OTPs — works fine with Dual SIM setup.
Yes — SMS OTPs don't require a data plan. They're delivered over the SMS channel, which works as long as your Indian SIM has any signal at all. With Dual SIM setup, your Indian SIM connects to whatever local network it can find (even if you don't have a roaming data pack) just to receive SMS.
No. Jio and Airtel numbers stay active as long as you maintain a minimum balance or active plan back home. Numbers are deactivated after 90 days of zero outgoing activity — but receiving calls and SMS counts as activity in most cases. Tell a family member to send you a WhatsApp message once a week if you're on a very long trip.
If your phone has a single physical SIM slot but supports eSIM, you're still good: put your Indian SIM in the physical tray and use the eSIM for travel data. If your phone has only one SIM slot and no eSIM, you'll need to choose: keep Indian SIM (miss local data) or swap for local SIM (miss Indian OTPs). Consider upgrading to an eSIM-compatible dual SIM phone before your next trip.
Yes. WhatsApp uses internet data, not a specific SIM's cellular plan. Once you have any data connection (eSIM or WiFi), WhatsApp works fully — calls, messages, status, groups.
Yes — UPI apps work from anywhere in the world as long as you have internet and access to your Indian bank account. The UPI transaction may trigger an SMS OTP to your Indian number; with Dual SIM setup, you'll receive it. Note: Some banks require you to be in India for international transactions over a certain limit.
Priya Sharma
Travel Tech Writer
Priya is a digital nomad who has lived across Southeast Asia, Europe, and the Middle East. She writes about connectivity, fintech, and smart travel for the modern Indian traveler.
India's only travel eSIM built for Indian travelers. UPI payments. Keep your Indian number. 5G speeds.
Get Early Access