The International CDMA switch appears on iPhone models sold for CDMA carriers, mainly Verizon and the former Sprint network, including the iPhone 7. It controls whether your iPhone can roam on CDMA networks outside the United States. This guide shows where the switch is, what turning it off does, how it relates to Data Roaming and Voice Roaming, and why you may not see it at all on newer versions of iOS.
Quick Answer
Open Settings > Cellular > Cellular Data Options > Roaming and turn off International CDMA. The iPhone will then roam only on GSM, UMTS and LTE networks abroad.
How to Turn Off International CDMA
- Open the Settings app.
- Tap Cellular (called Mobile Data in some regions).
- Tap Cellular Data Options.
- Tap Roaming.
- Turn off the International CDMA switch. It’s off when the switch is gray.
On some iOS versions, the Roaming options appear directly on the Cellular Data Options screen rather than on a separate Roaming page.
What International CDMA Does
CDMA and GSM were the two main families of cellular technology. Verizon and Sprint used CDMA in the US, while most of the world used GSM. With International CDMA on, a CDMA iPhone can connect to CDMA networks in the few countries that ran them. With it off, the phone uses GSM-family and LTE networks when you travel, which is what most carriers abroad use.
- On: the phone may roam on CDMA networks in other countries, which can carry different roaming rates.
- Off: the phone sticks to GSM, UMTS and LTE roaming partners. Calls and texts still work abroad if your plan includes international roaming.
International CDMA vs. Data Roaming vs. Voice Roaming
| Setting | What it controls |
|---|---|
| Voice Roaming | Whether you can make and receive calls on another carrier’s network |
| International CDMA | Whether the phone can roam on CDMA networks abroad |
| Data Roaming | Whether cellular data works on another carrier’s network, usually the biggest source of roaming charges |
To avoid surprise charges abroad, the setting that matters most is Data Roaming. See how to turn off data roaming on an iPhone 7.
Why You Might Not See the Switch
- Your iPhone model or carrier doesn’t use CDMA. GSM-only models, such as those sold for AT&T and T-Mobile, never showed it.
- CDMA networks have largely shut down. US carriers retired their CDMA networks around 2022, and many overseas CDMA networks have closed too, so newer iOS versions and carrier settings may hide the option.
- No SIM or an eSIM from a GSM carrier can also remove it.
If the switch is missing, you don’t need to do anything; your phone already roams on GSM and LTE networks.
Tips Before You Travel
- Check your carrier’s international plan or day pass before you leave.
- Turn off Data Roaming if you don’t have an international data plan, and use Wi-Fi instead.
- Consider a local SIM. The iPhone 7 has no eSIM, so you’d need a physical SIM, and the phone must be unlocked.
- Turn on Wi-Fi Calling (Settings > Phone > Wi-Fi Calling) if your carrier supports it.
Frequently Asked Questions
Will turning off International CDMA stop my phone from working abroad?
No. It only blocks CDMA roaming. Your iPhone still connects to GSM and LTE networks, which most countries use.
Does International CDMA use data?
It doesn’t use data by itself. Data use abroad is controlled by the Data Roaming switch.
Should I leave it on at home?
It has no effect on your home network, so on or off doesn’t matter while you’re in the US.
Summary
- Go to Settings > Cellular > Cellular Data Options > Roaming.
- Turn off International CDMA.
- Turn off Data Roaming too if you want to avoid roaming data charges.
- If the switch is missing, your phone or carrier doesn’t use CDMA.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.