OTP, Data-Only eSIM and SMS Verification Code Pitfall Guide

OTP stands for One-Time Password, which is typically the SMS verification code you receive on your phone.

For data-only eSIM used for travel, the conclusion is clear: the vast majority of data-only eSIMs do not have the ability to make/receive calls or send/receive SMS, so they cannot receive SMS verification codes. This is one of the most common eSIM pitfalls travelers encounter, especially when visiting popular destinations like Japan or Thailand.

Many people easily confuse a concept: eSIM is just a carrier; what determines whether you can receive SMS is the plan type.

1. Why Can't Data-Only Cards Receive Verification Codes?

When you purchase low-cost travel eSIMs on platforms like Airalo or Nomad, what you're buying is usually a Data-Only plan. Before purchasing, always verify your phone is eSIM-compatible using our eSIM checker.

• No real phone number: Carriers typically don't assign a number to this eSIM that can receive regular SMS and voice calls. It may only come with a virtual number used for underlying data routing.
• Physical channel limitations: The network configuration directly disables traditional voice and SMS signaling channels, only allowing data packets to pass through, meaning you can only access the internet.

2. When Will You Get Stuck Because You Can't Receive Verification Codes?

This is the deadlock many travelers encounter.

• Bank app remote login: When abroad, the bank detects IP or login environment changes and requires sending an SMS verification code to your domestic phone number; if your domestic card is unavailable, login will fail.
• Purchasing data packages requires verification: Some eSIM apps require sending an SMS verification code to the registered phone number when repurchasing data; if you only have a data-only card left, you may fall into a cycle of being unable to verify and unable to renew.
• Apple ID / Google account verification: When resetting your phone or re-logging into cloud accounts, SMS two-factor authentication may be required; if you can't receive verification codes, account recovery will be very troublesome.

3. How to Break the Deadlock?

Solution 1: Dual SIM Dual Standby (Most Recommended)

Keep both a domestic physical SIM card and a foreign travel eSIM in your phone.

• Turn off data roaming on your domestic card to avoid high data charges.
• Switch mobile data to the foreign eSIM.
• Keep the domestic physical card signal enabled to receive SMS verification codes.
• If your carrier supports it, you can also enable Wi-Fi Calling in advance.

The result: You use the eSIM's cheap data for internet access, while your domestic card can still receive SMS verification codes. Many domestic carriers offer free reception of overseas SMS, but it's still recommended to confirm with your carrier before departure.

Solution 2: Purchase eSIM with Phone Number

If you need to register local ride-hailing apps, send/receive local SMS, or make calls while abroad, check the plan description carefully when purchasing eSIM. After purchase, follow our iPhone installation guide to set it up correctly.

• Don't just look at data and price.
• Avoid plans only labeled as Data-Only.
• Prioritize plans explicitly marked with Voice, SMS & Data.

For example, some European traditional carriers' travel eSIMs will assign a real phone number, and such plans can usually send and receive SMS normally.

Solution 3: Switch to Non-SMS Verification in Advance

If you plan to only use a data-only eSIM, you should set up alternative verification methods for important accounts before going abroad.

• Bind email: Change verification code delivery method to Email.
• Use authenticator apps: Bind authenticator apps like Google Authenticator, Microsoft Authenticator.
• Save backup codes: For key accounts like Apple, Google, email, and bank, save recovery codes or alternative verification methods in advance.

Authenticator apps rely on local algorithms to generate dynamic passwords, not dependent on phone numbers. In many cases, they can even generate OTP without internet connection.

Conclusion

Data-only eSIMs are suitable for low-cost internet access, but don't expect them to receive SMS verification codes. The most secure approach before going abroad is:

• Keep your domestic primary card to receive SMS.
• Turn off data roaming on the primary card.
• Use travel eSIM for internet access. Browse and compare plans to find the best deal for your destination.
• Configure email, authenticator, or backup codes for important accounts in advance.
• Don't forget to check promo codes to save on your eSIM purchase.