Not registered with iMessage

I also have exactly same problem

ferrarr said:

Then if you get the message "not registered", that's something to do with your husbands phone.

Click to expand...

I am having exactly same problem on a new account that I am setting up on my MBP. I am able to send iMessage to A and B but not to C whereas they can send iMessages among each other
Me<->A OK
Me<->B OK
Me<->C NO
A<->B OK
B<->C OK
A<->C OK
A<->B OK

I read all of the responses above and checked that my Messages settings on phone and MBP both are configured as people suggested, yet it doesn't seem to send messages from MBP to one number. I am searching for solutions in this forum and appreciate if anyone can advise something that is not tried yet. TIA

I think I found a workaround that solved this issue. I sent an iMessage from my iPhone giving not registered error to my MBP and the message received on the MacBook messages application. Now can reply to the message from MBP to the iPhone, unlike before. After that, I deleted all the messages exchanged between phone and Mac and from my MBP, I am able to successfully sent messages to my iPhone.

It also solved the similar issue I was having with FaceTime in contacting this number. In case the original requester still has this issue, she can try it out. HIH

Just in case anyone else has this issue... it cropped up for me when I bought a new computer and cloned the old one to the new one. The fix was first making sure the new computer was registered with my iCloud account. BTW - If you clone, don't forget to go to preferences > sharing and change the computer's name to something for your new computer so you can uniquely identify it in your iCloud account. When you make it a clone, it just copies your setting from your old computer. In my case, other computer was a Macbook, and new computer was an iMac... so it was a little confusing at first when my "Macbook" showed up twice on my iCloud account. Anyhow, you don't have to fix it, but it makes it easier.

So the fix was that I needed to open preferences>messages on my phone and then go to Text Message Forwarding and enable the new computer. Once I did that, everything was back to normal after a reboot. I would imagine that this might even happen to someone who did not get a new computer, but decided to do a complete wipe and start over on existing computer maybe. So keep that in mind.

Welcome to our forums.

And thanks for the tip. Very good info to keep in mind.