Unify your phone number and email for your MacBook and/or iPhone
This will allow you to use your phone number to send and receive iMessages from your iPhone and your MacBook in a single unified chat thread and not two.
Anyone will tell you that I am a hardcore Apple Fan, however, sometimes they lack in the instructions area. For a while now I have had a problem with iMessages being sent from my MacBook. I could send an iMessage from my phone with no problem and my friend would receive it from my phone number however, the problem would arise when I would send a iMessage from my MacBook to to the same friend and a new thread would be created, so in essence she would have two different messages for me, one from my phone number and one from my email. After numerous attempts of contacting Apple Customer Service with no avail, I eventually figured it out on my own. I did aggrate some friends because I had to send messages relentlessly. In the end I found a solution and here are the instructions.
You’re going to go into iMessage on your computer, go to messages in the top left, click on preferences and then click on accounts. Look under “you can be reached for messages at” you should see your email and or your phone number.
If you do not see your phone number you need to add it to your account at this site. “
https://appleid.apple.com/” click on manage your Apple ID and then sign in. After you sign in you will go to another screen and on your left you’ll see a list of choices click on phone numbers. Add your phone number and click save changes. It usually takes a few seconds for your iMessage account to update. Completely quit iMessage in the toolbar and then reopen it and go back into messaging preferences and then accounts.
After that has been done your phone number should now be added to the “you can be reached for messages at” section. Click on your phone number and then uncheck your email address.
Then go into your iPhone settings, messages, then scroll down to send and receive. Uncheck any email, only your phone number should have a checkmark, if your phone number does not have a checkmark... check it. You should receive a pop-up on your iPhone saying so-and-so’s MacBook is now using “insert phone number here” for iMessages.