Several authors suggested that T-Mobile was the least expensive way to do this. But I was hoping that since the POTS line was with AT&T already that moving it to an AT&T wireless service would be easier.
Since there's a $38 fee for setting up a new line on my AT&T Wireless family plan I chose to go with AT&T's GoPhone offering with a $10 monthly plan.
I have an old Captivate that I could use for this so I went to the nearby AT&T corporate store to initiate the transfer.
The first salesperson couldn't remember how to do this and said that I would have to first get a GoPhone number then port the POTS number to it. I excused myself from him and found my usual salesperson. She made the transaction much smoother.
As I stood in the store chatting with the salesperson my cell phone rang. It was the AT&T transfer department They had an "error." My POTS line had 2 distinctive ring features that couldn't be ported. I said it was fine to drop these. He said he would make that change and put the request right back in the system. He said he expected it to be complete in 3 business days.
3 business days came and went. On the 4th business day I called the transfer department. They said that there had been more "errors." Each time the POTS group would kick it back to GoPhone. Then the GoPhone transfer department would fix the "error" and send it back to POTS. Repeatedly. Apparently the POTS group was only giving them one problem at a time.
The ETA was set at the 6th business day. My salesperson said that that actually meant midnight of the 5th day and that's how it worked out.
At 11:00 PM CDT (12:00 AM EDT) the Captivate got a text message that the port was complete. I immediately forwarded the Captivate to the temporary Google Voice number.
Within an hour Google Voice showed that it was eligible to transfer and I initiated the transfer. There were a few minor hoops to jump through and I paid them $20 using Google Wallet.
Be sure and get the account number for the GoPhone. You'll need to give that to Google Voice. AT&T calls that the BAN.
Exactly 24 hours after I submitted the port request to Google Voice:
We’re writing to let you know that your phone number: xxx-xxx-xxxx has been successfully ported to Google Voice!Finished! Or just starting?