You can permanently lose your carrier number

While a great idea in concept, as I was experimenting with the app, I lost the ability to forward to my original number.

If you set up more than two accounts, googlevoice will initiate a failsafe that will PERMANENTLY prevent you using your forwarding number. There’s NO warning provided to users about this before setting up the account. Essentially, if you attempt to create more than two accounts, google will prevent you from using your cell number - EVER AGAIN. Absolutely ridiculous.

Evan1212 about Google Voice, v2.15