In Germany we separately transmit the actual caller ID, which you can get shown based on your phone's UI. This can't be spoofed, or rather, it's illegal to do s

In Germany we separately transmit the actual caller ID, which you can get shown based on your phone's UI. This can't be spoofed, or rather, it's illegal to do so under https://www.gesetze-im-internet.de/tkg_2004/__66k.html https://www.gesetze-im-internet.de/tkg_2004/__66k.html . "mit einer Geldbuße bis zu hunderttausend Euro," is the wording for how much you'll pay if you, with intent or through negligence, transmit a number you are not assigned when you are user, or, if you are a telco, meddle with this header field _at_all_ if you didn't generate it, or didn't make sure it's a valid numbering scheme and not some premium number/short-dial-code. It's not limited to this, and so far this has not been a problem in Germany, at least as far as the CLIP itself goes, as the CLIP -no-screening- which the user can provide through his PBX if configured and contracted does sometimes, but rarely, mess up. Also we have a caller-pays system with a split between fixed-area landlines and floating mobiles, which seems to alleviate some of the problems with robocallers (the cost to even just waste the caller's time).