Google's made some strange decisions around how the Project Fi sign-up process works. The first wave of invites for Mountain View's MVNO phone service are now going out, offering new details on Fi's in and outs. If you're a frequent Google Voice user interested in being part of Project Fi, it's pretty critical that you pay attention. Entering Google's latest experiment could mean the end of Google Voice as you've known it until now.

The most bizarre thing about Fi is Google's policy for porting over Voice numbers. Project Fi will automatically recognize if an invited email address is tied to Google Voice, and from there you get two options: use your Google Voice number with Fi, or lose it entirely if you don't. There's no way of instructing the service to give you a new phone number and leave your existing Google Voice account untouched. Presumably this all relates to the technical side and back end of Fi, but it's a pretty terrible decision. It will likely result in some people deleting their Fi invite to preserve Voice.

It doesn't matter if you use your Google Voice number with Project Fi. If not, you'll lose it anyway.

Even if you do port over your Google Voice number, you'll essentially be giving up the older service anyhow. Google notes that once a Voice number has been transferred to Fi, you'll no longer be able to receive (or send) calls or messages through the company's Google Voice apps. And say goodbye to your voicemail and call history; those will no longer be saved with Voice once you've switched. (Old messages will be preserved.) You'll also lose out on making or receiving calls through Google Talk.

This all seems like a ton to sacrifice just to be part of Google's Project Fi, which is powered by a dual-network (Sprint and T-Mobile) setup, while also placing a huge focus on Wi-Fi connectivity. Google says many of Voice's existing conveniences like call forwarding, blocking, automatic voicemail transcriptions, and cheap international calling rates are making the move to Fi. And if you've already routed messages and voicemails to Google Hangouts, these changes may not seem so drastic. But to everyone still using plain old Google Voice, well, you should probably register for Fi with some other email address. Google's willingness to completely wipe away Google Voice accounts also speaks volumes about the service's standing at the company, and it doesn't seem to be a good one.