The database of licenses is public through the the ULS [0], and ae7q [1] has a bunch of archives and information about how to use that and provides tools itself that I used when finding a vanity.

-K5ETC

[0] https://www.fcc.gov/wireless/universal-licensing-system

[1] https://www.ae7q.com/query/stat/DataBase.php?SCHEMA=Lic

Verifying lisences is a messy process. Most processes I have experenced ask for an uploaded (official copy) pdf from the FCC ULS. LOTW sends a postcard to the registered address. LOTW certs can be used to “prove” your identity but it’s more complicated than most will endure.

For email.radio, I tend to just match the IP location to the address listed on the license. I also thought about using the navigator.geolocation location API to automatically verify users, but that could easily be spoofed.

I do know that some use postcards and make you upload your official license. EchoLink has an option to charge your card $1 to match your billing address to your callsign address automatically.

https://www.echolink.org/validation/validation_ccauth.jsp

Heh, I use privacy.com credit cards for all online purchases, and they approve any billing address.