This article explains how to delete your Google Voice account. Additional information covers how to recover your Google Voice account.
How do I delete my Google Voice number?
It is possible to disable Google Voice or opt out of Google Voice altogether. There are a few things to keep in mind, however. If you use Google Voice with an existing Sprint account or service, or if you paid to port your number, you cannot delete it. Also, deleting your Google Voice number does not erase all of the data associated with your account, meaning that messages will remain in your inbox.
To permanently delete a Google Voice account, follow these steps.
Go to the official Google Voice website.