Aircraft that fly where transponders aren't required wouldn't be using any air traffic facilities so wouldn't be charged anyway.
Here we go, so you get a bill in the mail from "ATC Services Inc" for an IFR flight from X to Y, and your plane was parked in the hangar at that time down for annual, what do you do? Even with ADSB, one can cheat on the broadcasted N #
Forgot to mention...
I did remember to take my Navworx out of the 1200 anonymous mode so they could see my number. After the test I returned to tah mode. Wish they would provide a UAT control console for the Android phones. I have to use my friends Apple phone.
John, won't this do it? (https://play.google.com/store/apps/details?id=com.app.wificommunicator)