iMessage lets you send messages from your Apple device to other Apple users. It uses data, and if you aren’t connected to Wi-Fi, anything you send will come out of your data allowance.
If you try to send an iMessage without an internet connection, it will be resent as a text or picture message.
Text messages will come out of your text allowance if you have one. If you're sending an attachment like a picture, video clip or an Animoji, this will be charged as a picture or video message, unless you have an Extra
If you don’t want your device to automatically resend iMessages as texts and picture messages when you have no data connection, you can turn this feature off by going to:
- Turn off Send as SMS
If you try to send an attachment like a picture, video clip or an Animoji to a non-Apple device, you’ll automatically send a picture or video message.