I thought I’d share my experience. I basically followed what other people suggested,
- Purchase an AT&T pay-as-you-go sim card kit (https://www.att.com/cellphones/prepaidphones/sim-card-kit-phone-prepaid.html). During the ordering process there will be an option to port a number to the sim card. Select that option and enter your Vonage details. You’ll need to know your Vonage Account Number (this is not the same as your phone number) and your Vonage PIN. This will cost $0.99. You’ll be asked to select a service plan, and it will add a $25 prepay to the plan. Delete the prepay. Check out paying only $0.99.
- Wait for the SIM Card Kit to arrive. 3-5 days.
- Install the SIM Card in an unlocked or AT&T phone. I had some issues with this, as my older phone would not work with the AT&T towers. I ended up calling AT&T for support, and they activated the SIM card and confirmed the port, though we could not get the older phone to work. I eventually installed the sim card in an iphone 5S, and it worked fine.
- Log in to paygoonline and add $10 to your account. You’ll need some money in the account so that you can receive text messages (from Google voice) on the SIM card. $10 is the minimum. If necessary, reset your PIN — it’ll text the phone with a temporary PIN, and you can use that to log in to the site.
- Call AT&T and ask them for the Account Number for your pay-as-you-go SIM card. You can dial 611 from your phone to contact AT&T. The account number is not the same as your phone number. As far as I know, the only way to get this is to talk to a representative. If they ask why you want it, tell them you want to have the option to port your phone and want the necessary information on hand.
- Log into google voice and select the option to port your phone. Google will text you an authorization code to your phone, and you will have to retrieve that code from the phone and type it into google voice. Google voice will need your AT&T account number (which you called AT&T and talked to a rep in the previous step). It did not as me for the PIN number. Google will ask you to pay $20.
- Wait approximately 24 hours and your number should be ported to Google Voice.
- 24 hours after the port to Google Voice, my Vonage account was canceled automatically.
This ended up costing me $30.99 in total, $0.99 for the SIM card, $10 to AT&T for the pay-as-you-go plan, and $20 to Google to port the phone number.