You may remember a couple of months back Google made it possible to port your own number over to Google Voice. The downsides to that were that after a 90 day transition your original number, and it’s text messages were gone, for good.
Google has now decided to allow you to keep your original Google Voice number for a one time fee of just $20 this means essentially that you can have two numbers on one Google Voice account. The only caveat seems to be that texts will show with the ported number and not the original number.
It’s really easy to do this if you want to just go to your Google Voice account, hit settings and by the original number hit make permanent.
It’s that easy.
Source: Android Police