IPhone 11 usage

Hi Grateful20,

Welcome to the Apple Community.

(We are all Apple users, like yourself, doing our best to help each other troubleshoot.)

Sorry I don't know much about using iPhone without a SIM ... you would likely keep getting error messages.

However:

Apple support do have articles online that may help in your situation:

Eg: "Make and receive FaceTime calls on iPhone"

Says:

"With an internet connection and an Apple ID, you can make and receive calls in the FaceTime app .

Note: You must set up FaceTime before you can make and receive calls.

You can also make FaceTime calls over a cellular data connection, which may incur additional charges.

NB: To turn this feature off, go to Settings > Cellular, then turn off FaceTime.

Complete article: https://support.applehttps://support.apple.com/en-au/HT207006

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Then:

The article: "View or change cellular data settings on iPhone"

Says:

:You can turn cellular data and roaming on or off,

set which apps and services use cellular data, see cellular data usage, and set other cellular data options."

AND

"If Cellular Data is off, all data services—including email, web browsing, and push notifications—use Wi-Fi only.

If Cellular Data is on, carrier charges may apply.

Complete article: https://support.apple.com/en-au/guide/iphone/iph3dd5f213/15.0/ios/15.0

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Re: Messages App:

It seems messages are sent over wi-fi, if available. (If no wi-fi, then cellular is used for SMS/MMS.)

You might want to view this article:

What is the difference between iMessage and SMS/MMS?

https://support.apple.com/en-au/HT207006

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Hope this helps you :-)

You're Welcome, Grateful20.

Thank you so much for your reply, and for letting us know you solved the issue.

Cheers :-)