When turned on, Wi-Fi Calling may improve call quality while indoors.
Wi-Fi calls always originate in the US, even when you're outside of the US.
Calls to US numbers are not billed (except for 411 or other premium calls).
Calls to international numbers are billed according to your international long distance plan.
From the Home screen, navigate: Apps icon > Settings > Advanced Calling.
If unavailable, navigate: Apps icon > Settings > More > Advanced Calling.
For Oreo OS, navigate: Apps icon > Settings > Network & Internet > Mobile network > Advanced > Advanced Calling.
For Samsung devices, navigate: Apps > Settings > Connections.
For Samsung devices with Pie OS, navigate: Phone icon > Menu icon (upper-right) > Settings.
Tap Wi-Fi Calling.
Tap When Roaming.
For Oreo OS, tap Roaming Preference then choose Wi-Fi or Mobile and begin using your choice.
For Pie OS, tap Roaming network preference then choose Wi-Fi or Mobile network and begin using your choice.
Tap one of the following available options:
Prefer Other Cellular Networks (Roaming changes may apply)