If SMS verification codes stop arriving abroad, check the home SIM first. Keep the line enabled, confirm that it can register on a local partner network, and test ordinary SMS before requesting another code. This is the first check when you are not receiving OTP while abroad. A travel eSIM can provide data while your original number remains active for messages.
This guide covers travel, relocation, study and legitimate access to your own accounts. It does not replace carrier rules or a service's sign-in policy. If you are roaming not receiving OTP, check the home line before changing the account number. Never use a temporary number or public inbox for banking, payment, identity or account recovery.
Why SMS verification fails abroad
Changing countries often changes several things at once: the phone registers with a different carrier, a local SIM becomes the default data line, and the service sees a new sign-in location. Any one of these changes can interrupt the path between your account and your registered number.
Mobile data and SMS are separate. Turning off data roaming usually stops internet use on that line; it does not necessarily stop incoming SMS. Disabling the entire home line does. If the original number cannot register on a visited network, the carrier has no cellular route for the message.
A practical example makes the distinction clear. Put a home SIM and a travel eSIM in the same phone. Set the travel eSIM as the cellular-data line, turn data roaming off for the home SIM, and leave the home line enabled. The travel eSIM handles maps and messaging apps, while the home line still has a chance to receive a code.
What to check when SMS verification codes are not received
1. Keep the registered line enabled
On iPhone, open Settings, then Cellular, and check that the home number is switched on. On Android, open SIM management and confirm the same line is active. The exact labels vary by model, but the rule is simple: the number registered with the account must remain available for cellular service.
Do not assume that visible signal bars prove SMS delivery. Check the home line itself. Send a normal text to it from a trusted contact, or use a non-critical account for a test code. If neither arrives, solve the carrier or SIM problem before blaming the verification service.
2. Select the right SIM for data
With dual SIM, assign the local SIM or travel eSIM to mobile data. Keep the home SIM enabled for its number. Some phones also have separate defaults for calls, messages and data, so review each setting instead of changing only the data option.
On a trip, a safe arrangement is: local eSIM for data, home SIM active, home-SIM data roaming off. If the home carrier requires voice roaming for inbound SMS, enable that setting after checking the carrier's terms. Charges and requirements differ by carrier and destination.
3. Check roaming and network registration
Log in to the carrier's official account page before departure and confirm international roaming is available in the destination. If the line shows “no service,” try automatic network selection first, then manual selection if the carrier documents a partner network. Allow a few minutes for registration after changing networks.
If you changed to a local SIM, do not delete the home eSIM just because it is not carrying data. You may need that line for SMS, and reinstalling an eSIM while abroad can require account access or a carrier-issued activation process.
4. Check message filtering
Review blocked senders, spam folders and SMS filtering on the phone. International short-code messages can be sorted differently from ordinary texts. Check the account's phone number format too. For example, a Vietnamese number should normally use the international +84 format without repeating the leading zero, but the service's own instructions take priority.
5. Stop repeated requests
Repeatedly tapping “resend code” can create several active codes or trigger a temporary sign-in restriction. Request once, wait through the stated delivery window, then use the service's documented recovery route. If a code arrives late, enter the newest one rather than an earlier message.
Use a safer backup than SMS
SMS is convenient but depends on the carrier path. Before travelling, move important accounts to an authenticator app, passkey or trusted-device prompt when the service supports it. A time-based authenticator generates a six-digit code locally, so it does not need mobile signal; keep the device clock set automatically and verify the account entry before leaving.
Save backup codes in a password manager and in a secure offline place. Treat them like passwords. A backup code that works once is useful when the phone is lost, the home line has no roaming partner, or the service blocks an unusual foreign sign-in.
Prioritise your primary email, password manager, work accounts and financial services. For these accounts, a short-term number is a poor recovery method because access may end or the number may later be reassigned.
Can you receive SMS abroad without data roaming?
Often, yes. The home line must stay enabled and be allowed to register on a partner network, while data roaming can remain off. This prevents the home SIM from using mobile internet, but it does not guarantee delivery when the carrier has no agreement at the destination.
Wi-Fi Calling may help if the carrier supports SMS through it and the feature works in that country. Enable it at home, connect to Wi-Fi, and confirm the phone shows the feature as active before relying on it. A travel eSIM with data does not automatically carry SMS sent to your home number.
Lost SIM cannot receive OTP: what to do
If the SIM is lost, contact the original carrier through its official support channel and request a replacement or eSIM transfer after identity checks. Do not post the number, account details or verification codes in a public forum. If the number has been cancelled, ask whether recovery is possible before trying to change every account at once.
For a controlled account, update the phone number only after you have another sign-in method working. Record which services were changed and keep the old recovery details private until the transition is complete.
Pre-trip checklist
- List accounts that still rely on SMS.
- Set up an authenticator app, passkey or trusted device for critical accounts.
- Download backup codes and store them securely.
- Confirm roaming support for the destination.
- Install the travel eSIM without disabling the home line.
- Set the travel eSIM as the data line.
- Test an ordinary SMS and one non-critical verification code.
- Write down the carrier's official support route.
Frequently asked questions
Verification code not received: why regular texts still arrive
The carrier path may work while the service delays or blocks a code because of sign-in risk, short-code handling or a location change. Use an approved backup factor instead of repeatedly requesting SMS.
Can a travel eSIM receive codes sent to my home number?
Only if the travel eSIM has its own supported number and the account is registered to that number. A data-only travel eSIM cannot receive SMS addressed to your home SIM.
Should I rent a virtual number while abroad?
Use one only for a permitted, low-risk purpose where you control the account and do not need future recovery. A rented number is not a substitute for your original number, a carrier replacement or a durable second factor.