No code for Text Message Forwarding?

Hello ckim17,
I understand that you are having issues with setting up Text Message Forwarding on your Mac but you're having some issues. Let's see if we can get this sorted.
Now I know you have done some troubleshooting on your end, but check out the two articles below. The first will walk you through setting this up and to ensure that you didn't miss anything in that process. The second will give you some additional troubleshooting that you can try along with what you have already done.
Use Continuity to connect your iPhone, iPad, iPod touch, and Mac
https://support.apple.com/en-us/HT204681
Get help using Continuity with your iOS device or your Mac
https://support.apple.com/en-us/HT204678
Take care

Like many others looking for a solution to this problem, I'd tried them all but my MacBook Pro still wouldn't display the text message forwarding code.

The solution I found was simple but strange:

• Use another iOS device (I used my iPad) to turn on Messages (Settings/Messages then login as requested). If Messages was already switched on, try deactivating and reactivating it (I didn't need to do this)
• On your iPhone go into Settings/Messages/Text Message Forwarding and you should see the other iOS you just set up
• Turn on Text Message Forwarding for that device and a 6 digit code should appear on it
• Enter the code into your iPhone as requested
• Then try turning on Text Message Forwarding for the OS X device you're having trouble with (in my case it was a MacBook Pro running El Capitan)
• Magically, the 6 digit code should then pop up correctly on the OS X device
• Enter that code into your iPhone as requested and it will all hopefully work OK

I presume you made sure that the 2nd iPhone you used was logged into the same iCloud account as the OS X device and that both devices have the same email address to use for Messages.

Hi ckim17,
If you have followed all the previous steps and ensured that everything is setup properly, then the next step would be to contact Apple Support to further help you out. You can start that process by using the link below.
Contact Apple Support
https://www.apple.com/support/contact/
Have a good day

My problem came back when I upgraded to the newest El Capitan beta so I spent another few hours trying to fix it. In the end it went like this:

• Logged out of iCloud on my Macbook and my iPhone
• Removed my Macbook as a device in iCloud (log into iCloud.com to do that)
• Quit Messages on my Mac and then all of a sudden lots of 4 digit codes started arriving from all the previous attempts I'd made to set up Text Message Forwarding as if they'd been building up in the background somewhere
• I hit cancel on all of the 4 digit code messages and then re-quit Messages
• Restarted my iPhone and Macbook
• Logged back into iCloud on my iPhone and Macbook
• Turned on Text Message Forwarding on my iPhone for the Macbook
• A 4 digit code appeared on my Macbook as it should - entered that number on my iPhone
• Everything now working

So my problem came back yet again when I upgraded to the latest El Capitan beta. After trying everything that worked in the past with no luck, I tried something simple and it worked:

- disconnect your iPhone and Macbook from all WiFi networks

- turn on Personal Hotspot on your iPhone and connect to it using your Macbook

- go into Text Message Forwarding under Messages (on your iPhone)

- select the Macbook device you want to use to send text messages from

- the access code should appear on your Macbook!

- enter it into your iPhone and away you go.

I haven't been able to get Text Message Forwarding working on my Mac Mini since installing the El Capitan 10.11.4 update despite many attempts. The solution from SimBock above worked first try, thanks!