How do you switch back to iMessage

Have you signed out of the iPhone, then back in? Have you tried going to settings > general > reset network settings?

My advice is to sign out of the device, reset network settings, restart, then sign. Into device to try again.

The same thing is happening to me with only one contact. From my iPhone my text is sent as a text message (green), but from my iPad the same contact receives iMessages. Checked the settings on my phone and iMessage is enabled. Not sure why this is happening.

I was having the same issue until I went to my iPad and it asked to confirm my new device in which I said yes. Then I sent a iMessage from my ipad to the contact I was trying to sent an iMessage to originally and the conversation turned blue. Now it works. If you have more than one Apple device maybe it wants to sync across all devices? Try it!

Switch back to iMessage ... from what? Why?

Please describe your exact scenario. "Back" ... so you used iMessage at some point in the past. Then something happened...

The same happened to me with 2 contacts already. I’ve turned imessage off and on many times, checked the addresses and we all have wi-fi. Don’t know what to do anymore, it’s making me mad