I have a Mac running Mountain Lion and an iPhone5 running iOS7
I have confirmed that the Apple account setup in messages in my Mac and iPhone are the same account.
However when I send a message to my wife's iPhone from my Mac it shows up as a separate thread (same name) than when I send a message from my iPhone. She will have 2 threads on her phone, when she responds to the thread started from the Mac, only my Mac will receive the message. When she responds to threads sent from my iPhone, only my iPhone receives the messages.
It like iMessage on my Mac vs iPhone are acting like 2 separate accounts even though they are both using the same Apple ID.
Is there anyway I can resolve this?
I tried followed the instructions here but there was no setting titled Use your Apple ID for iMessage. The settings may have changed since the last version of iOS I am guessing.
Best Answer
When I went to Preferences > Accounts within Messages on my Mac under:
It was only listing my email address (no phone number).
Logging out and back into Messages on my Mac, caused the phone number to show up here. Checking it fixed the problem and they are now synced.