swapping iPhone on family plan with AT&T

All iPhone models are world phones, so you can use them almost anywhere. Whether you are a GSM or CDMA network customer, you can roam internationally on GSM networks in over 200 countries or regions around the world. Availability of LTE data varies in some countries or regions and depends on carrier support for certain LTE radio frequencies. Contact your wireless carrier for more information regarding international roaming policies and rates.

1. Wireless network provider support and features for iPhone · Afghan Wireless · Roshan · American Samoa Telecommunications Authority. Wireless network provider support and features for iPhone ...
2. Wireless carrier support and features for iPhone · eSIM · FaceTime over Cellular · Personal Hotspot · VoLTE · Wi-Fi Calling. Andorra. Andorra Telecom Find wireless carriers and worldwide service providers that ...

If you desire to buy a brand-new iPhone then

1. Purchase Apple Products from the Apple Online Store, Apple Retail Stores, and many Apple-authorized resellers and wireless service providers.
2. If you choose "Connect to a carrier later" (Unlocked iPhone) when you buy your iPhone, you can activate your service when you receive your device.
3. If you're asked to transfer your SIM, follow the onscreen instructions to transfer service from your previous iPhone. To learn more, visit About eSIM on iPhone - Apple Support.