I don't even want to guess the percentage of couples where one partner pays for (both, maybe three) phones/landlines, and that's ignoring all children, underage or not.

I currently pay for 4 other people, because the way plans work in the US, it’s a lot cheaper.

I don’t bother to update the names on their lines, so they all probably link back to me.

So were they engage in something illegal you would be liable?

only if police and judges are stupid.

So depends on their mood, corruption, and whether they want to get you.

If you live in a shithole country that's always the case.

I’m sure the police would come to my door, but I could show records of it not really being “my phone number”.

Family plans are pretty common here, so I wouldn’t expect too much friction.

I would absolutely cooperate (obviously through a lawyer) with records if someone else on my family plan did something illegal.

I also have records showing that they pay me for the line.

Also yes, it would be a huge hassle. The probability of that happening is small, and I’m willing to risk it like many other things in life. I only do this for very trusted people.

Don't remember what service exactly (Paypal I think?) that some time ago asks for me to "verify" the account by showing some bills with my name. At that point, the only utility bills they accepted for the verification, were all in my wife's name, which they didn't accept, so now I no longer have Paypal.

Good point. I actually think we're both on some of the statements, so that's at least one problem I wouldn't have. Still ridiculous overall, of course.