Add another Google Voice number to your account
As a general rule, your Google Voice account can have only one number associated with it. If you already have a Google Voice number, you can transfer it to your Fiber Phone number, or choose a new Fiber Phone number, which replaces your Google Voice number.
If you want to keep your Google Voice number and get a new Fiber Phone number, you have two options:
Add a user to your Fiber Phone account.
Keep your original Google Voice number as a secondary number.
Keep your original Google Voice number
You can keep your original Google Voice number as a secondary number for a one-time $20 fee. Calls and text messages to both numbers will reach you, but outbound calls and texts will be sent only from your main Google Voice number.
To keep your original number:
Within 90 days of changing or transferring a number, open Google Voice on your computer.
At the top left of your screen, click Menu and then select Legacy Google Voice. Google Voice will look different, but you're in the right place.
At the top right, from the Settings menu, choose Settings.
Click the Phones tab if it isn't already selected, and then click Make Permanent next to your old number.
Follow the onscreen instructions to confirm and pay. After you've paid, the expiration date next to your original Google Voice number disappears.