No, a Thailand eSIM cannot receive Indian OTPs. An OTP is locked to your registered Indian mobile number, not to any device or eSIM profile. Keep your Indian SIM active with international roaming enabled for SMS. Use the Thailand eSIM only for data.
This mix-up trips up most first-time travelers using eSIMs, since the data works instantly and feels like the whole phone has switched over. It has not. Two separate lines are doing two separate jobs.
Why Doesn't a Thailand eSIM Receive Indian OTPs?
A Thailand eSIM is a separate data line with no connection to your Indian phone number. Banks, UPI apps, and government portals send OTPs to the exact number registered on your account.
A Thailand eSIM is a separate data line with no connection to your Indian phone number. Banks, UPI apps, and government portals send OTPs to the exact number registered on your account.
Installing a travel eSIM does not redirect this. Your Indian bank does not know a Thailand eSIM exists. It sends the OTP to your Indian Airtel, Jio, or Vi number, exactly as it always has. If that number cannot receive SMS abroad, the OTP simply does not arrive.
This applies to every service tied to your Indian number, not just banking. Aadhaar-linked verifications, DigiLocker, brokerage apps like Zerodha, credit card approvals, and even email account recovery all rely on the same registered number. A Thailand eSIM has its own separate number, or none at all on data-only plans, so none of these services have any way to reach it.
How Do You Keep Receiving OTPs While Using a Thailand eSIM?
Keep your Indian SIM active with international roaming, and set your Thailand eSIM as the mobile data line. This dual-SIM setup lets one line handle SMS and the other handle data.
Activate an international roaming pack on your Indian SIM before flying. Airtel, Jio, and Vi all offer packs built for this. Confirm the pack includes free incoming SMS before buying it.
Once installed, assign Mobile Data to the Thailand eSIM. Turn Data Roaming off on the Indian SIM. This keeps the Indian line reachable for texts without triggering expensive roaming data charges.
On iPhone, this means setting the Thailand eSIM as the Cellular Data line in Settings, while confirming Data Roaming stays off under the Indian SIM's own settings. On Android, the same split is made through SIM manager, where mobile data is pointed to the Thailand eSIM and roaming stays disabled on the Indian line. The Indian SIM remains switched on the entire time purely to receive calls and texts.
Why UPI and Similar Apps Need Extra Care
UPI and some banking apps occasionally send an outgoing verification SMS, not just an incoming OTP. This outgoing text can fail if the Indian SIM has no balance or weak signal on roaming. Confirm your roaming pack allows outgoing SMS if you plan to use UPI abroad.
What If Your Phone Only Has One SIM Slot?
Convert your Indian SIM to an eSIM to free the physical slot, or carry a secondary phone dedicated to your Indian number. Both options solve the single-slot problem.
Converting the Indian SIM to an eSIM usually takes a quick SMS request and a QR code scan through your carrier. Once done, the physical slot is free for a local Thailand SIM if you prefer one over a travel eSIM.
Carrying a spare phone is the simpler option. Keep it charged, insert the Indian SIM, and leave mobile data off. It becomes a dedicated OTP receiver while your main phone runs the Thailand eSIM.
Neither option is strictly necessary if your phone already supports dual SIM or dual eSIM. Most phones released since 2020, including recent iPhones and Galaxy models, handle one physical SIM plus one eSIM, or two active eSIMs, without any workaround needed.
Are Incoming OTP Texts Free While Roaming?
Incoming SMS is typically free on international roaming packs, even OTP texts. Sending texts may cost extra, so check your specific carrier's pack details before you fly.
Most Airtel, Jio, and Vi roaming packs advertise free incoming SMS as a core feature. Read the plan's fine print for validity period and exact inclusions, since terms vary by pack and destination.
A basic roaming pack with just free incoming SMS is usually enough if the only goal is receiving OTPs. Larger packs that bundle data or outgoing minutes cost more and are worth it only if you plan to use the Indian line for calls too, alongside the Thailand eSIM handling data.
What If an OTP Still Doesn't Arrive?
Restart your phone, confirm the Indian SIM has roaming enabled, and try manual network selection if automatic registration fails. Most delayed OTPs resolve within a few minutes using these steps.
Work through the checks in order. Confirm the Indian line shows signal, not just power. Check that data roaming being off has not also disabled SMS by mistake. Look in spam or blocked-sender folders, since some Android phones filter unfamiliar international senders.
If none of these fix it, the delay may sit with the sender rather than the phone. International SMS routes between the Indian bank's gateway and the Thai partner network can lag by a few minutes during peak hours. Waiting briefly before retrying often resolves this without any settings changes at all.
A Quick Example
A traveler in Bangkok tries to pay a hotel bill and needs a bank OTP. Nothing arrives after two minutes. The fix: toggle the Indian line off, then on, to force it to re-register. Confirm roaming is active. Wait sixty seconds. If still nothing, switch to the bank's authenticator app instead of waiting further.
Backup Options
Authenticator apps like Google Authenticator or a bank's own app-based approval generate codes directly on the device, without needing SMS at all. Setting one up before departure removes dependence on SMS delivery entirely for supported accounts.
Not every Indian bank supports authenticator apps yet, since many still rely solely on SMS for regulatory reasons. Check which of your accounts offer this option before the trip, and enable it for at least email, UPI apps, and any service that allows it, so SMS is not the only path in for critical logins.
Keep Your Phone Charged
None of this setup matters if the phone battery dies. Carry a power bank and the correct plug adapter for Thailand. A dead phone cannot receive an OTP no matter how well the SIM and eSIM are configured.
FAQs
Can I skip Indian SIM roaming entirely and only use the Thailand eSIM?
No, this cuts off OTP access completely, since OTPs only reach the Indian number, not the eSIM.
Does keeping the Indian SIM active drain the battery faster?
Slightly, since the line stays registered on a network, but the effect is minor compared to active data use.
Should I delete the Indian eSIM or SIM profile if I am not using it for calls?
No. Deleting it while traveling can be difficult to reverse and cuts off OTP access until you are back on a trusted network.
Does WhatsApp OTP work the same way as bank OTPs abroad?
Yes. WhatsApp verification also goes to your Indian number by SMS, so the same roaming setup applies.
Will I get charged for receiving OTPs while roaming in Thailand?
Usually not. Incoming SMS is typically free on Indian roaming packs, though sending texts may cost extra.
Can I use an international roaming pack instead of a Thailand eSIM for data too?
Yes, but it usually costs more than an eSIM for data, so most travelers keep roaming only for SMS and use the eSIM for data.
Simju's Thailand eSIM plans handle data only, so pairing one with an active, roaming-enabled Indian SIM keeps both connectivity and OTP access working through the trip.