Log in to voice.google.com and click the settings tab. Then click "Voice Settings."
Click "Change/Port" to choose the mobile number you'd like ported.
This pop up box will ask you if you want a new Google Voice number or to import your existing mobile number. Choose the second option.
You're taken to the Number Porting menu. First, enter your mobile number and click "Check." This will verify your number can be ported.
Google will ask you to agree to a long list of conditions before moving on. They make it very clear your current mobile plan will be disconnected. If you agree, check all the boxes and click next.
A pop up window will give you a verification code. Click "Call Me Now" and wait for your phone to ring. When prompted, enter the code on your screen.
After you input the verification code, your screen will automatically move to the next step (pretty cool). Google will detect your carrier and ask you to input your billing information. When you're done, click "Next" to bill $20 to your Google Checkout account.
Wait for your number to port
Now wait. It will take up to 24 hours for your number to port over. In the meantime, contact your carrier and set up a new contract and mobile number for your phone. Google will send you an email when the port is complete.
If you have an iPhone, make sure you download the free Google Voice app and check out our guide on how to use it.
After the port is complete, you must make your new mobile account the forwarding number for Google Voice. Go back to Settings and click "Add another phone."
Enter a name for your phone and its number. You should also make sure the box next to "Text Settings" is checked so you'll receive texts on your phone too. Click the save button. Now all calls to your original ported mobile number will go to your phone.
Check out this video from Google explaining how number porting works
Number Porting
