Short answer
Apple says both phone numbers can send and receive SMS, and a one-time SMS passcode is a text of that kind. Apple says to contact your carrier about international roaming, and if you use only the travel eSIM, that article names FaceTime and iMessage, not SMS.
Keeping both lines on, choosing the data line, and home-line roaming are covered in Can I keep my home number and use dual SIM in Japan?.
Fact table
As of 2026-10-21
Each claim names its source. The full source list, with the date each page was read, is below.
| Claim | Source |
|---|---|
| Apple says both phone numbers can send and receive messages using iMessage, SMS, and MMS, and that the iPhone uses one cellular data network at a time. | Apple Support, Dual SIM with an eSIM |
| Apple says additional fees might apply when you send an iMessage, SMS, or MMS from either phone number, and to check with your carrier. | Apple Support, Dual SIM with an eSIM |
| Apple says that if data roaming is on for the number that uses cellular data, the voice-only number disables Visual Voicemail and MMS. That note does not name SMS. | Apple Support, Dual SIM with an eSIM |
| On roaming with your existing carrier, Apple says to check before you travel whether that carrier includes international roaming, and to contact the carrier to learn more. Apple says international roaming with an eSIM works the same as roaming with a physical SIM. | Apple Support, travel with eSIM |
| If you use only the travel eSIM, Apple says FaceTime and iMessage continue to work on your home line. That sentence does not name SMS. | Apple Support, travel with eSIM |
| Apple says that when you sign in to some websites and apps, a one-time SMS passcode is sent to your iPhone. iPhone can detect the passcode in Messages and display it above the keyboard. | Apple Support, SMS passcodes |
| Apple says iPhone can automatically generate verification codes without your reliance on SMS messages or additional apps. | Apple Support, verification codes |
| For an Apple Account, Apple says you can use the code displayed on a trusted device, or get a text message or phone call sent to your trusted phone number. | Apple Support, Apple Account verification code |
| If you use Unknown Senders filtering in Messages, Apple says to check there for the Apple Account verification code. Apple says you can turn on notifications for time-sensitive messages so those codes can still reach the Messages inbox. | Apple Support, Apple Account verification code |
| Google says a 6-digit code is sent to a number you previously provided. Codes can be sent in a text message or a voice call, depending on the setting you chose. | Google Account Help, 2-Step Verification |
| Google says prompts arrive as push notifications on Android phones signed in to your Google Account, and on iPhones with the Gmail app, the Google Photos app, the YouTube app, or the Google app signed in. Google recommends prompts as the second step. | Google Account Help, 2-Step Verification |
| Google says you can still generate codes with the Google Authenticator app without an internet connection or mobile service. | Google Account Help, Google Authenticator |
FAQ
Can an SMS sign-in code still reach my home number?
Apple says both phone numbers can send and receive SMS and MMS, and that a one-time SMS passcode is sent to your iPhone. Apple says to contact your carrier about international roaming. Additional fees might apply when you send an SMS from either number.
Does that text use the line I selected for data?
Apple says both phone numbers can receive SMS, and that the iPhone uses one cellular data network at a time. Google says its 6-digit code is sent to a number you previously provided, by text message or voice call.
What if I use only the travel eSIM?
If you use only the travel eSIM, Apple says FaceTime and iMessage continue to work on your home line. That sentence does not name SMS.
Does data roaming on the data line turn SMS off?
Apple says that if data roaming is on for the number that uses cellular data, the voice-only number disables Visual Voicemail and MMS. That note does not name SMS.
Can I sign in when the code is not a text?
Apple says iPhone can generate verification codes without reliance on SMS messages, and that an Apple Account code can display on a trusted device. Google says Authenticator can generate codes without an internet connection or mobile service, and that prompts are push notifications on signed-in devices.
Where does Apple say to look if the text is missing?
If Unknown Senders filtering is on, Apple says to check there for the Apple Account verification code. Apple says those codes can still reach the Messages inbox when notifications for time-sensitive messages are on.
Sources
Apple Support, Dual SIM with an eSIMsupport.apple.com
Both phone numbers can send and receive iMessage, SMS, and MMS. The iPhone uses one cellular data network at a time. Sending an iMessage, SMS, or MMS from either number might mean additional fees, and Apple says to check with the carrier. If data roaming is on for the number that uses cellular data, the voice-only number disables Visual Voicemail and MMS. That note does not name SMS.
Accessed 2026-10-21.
Apple Support, travel with eSIMsupport.apple.com
Before travel, check whether the carrier includes international roaming, and contact the carrier to learn more. International roaming with an eSIM works the same as with a physical SIM. If you use only the travel eSIM, FaceTime and iMessage continue on the home line. That sentence does not name SMS.
Accessed 2026-10-21.
Apple Support, SMS passcodessupport.apple.com
When you sign in to some websites and apps, a one-time SMS passcode is sent to the iPhone. iPhone can detect the passcode in Messages and display it above the keyboard.
Accessed 2026-10-21.
Apple Support, verification codessupport.apple.com
Some websites and apps use a temporary one-time verification code as a second factor. iPhone can generate these codes without reliance on SMS messages or additional apps.
Accessed 2026-10-21.
Apple Support, Apple Account verification codesupport.apple.com
An Apple Account sign-in can use the code displayed on a trusted device, or a text message or phone call to the trusted phone number. If Unknown Senders filtering is on, check there for the code. Time-sensitive notifications can still let those codes reach the Messages inbox.
Accessed 2026-10-21.
Google Account Help, 2-Step Verificationsupport.google.com
A 6-digit code is sent to a number you previously provided, by text message or voice call, depending on the setting. Prompts are push notifications on Android phones signed in to the Google Account, and on iPhones with the Gmail, Google Photos, YouTube, or Google app signed in. Google recommends prompts as the second step.
Accessed 2026-10-21.
Google Account Help, Google Authenticatorsupport.google.com
The Google Authenticator app can still generate codes without an internet connection or mobile service.
Accessed 2026-10-21.