>Assume everyone asking for such things are scammers.
That's excellent advice, and everyone should follow it. Unfortunately some banks disagree and will cancel your credit cards when you fail one of their fraud check phone calls.
> And guess what, the only way to be sure that it’s your bank you’re talking to, is to call them yourself. Period. Some callers tell you details of your account as a way of identifying themselves.
There's a scam in the UK where they call you, and ask you to call them back. You hang up, then pick up the phone and dial the number. But because they initiated the first call the line doesn't clear until they hang-up, and they don't hang up while you're dialling the number. (And the sometimes play recorded ring tones before they "answer").
It varies a lot, or at least it used to. Keeping the phone line open and expecting a callback is a scam so classic it's even in the first edition of "Practical Unix (now "and Internet") Security" in the section on securing your modem pool.
> Call charging ends when the telecoms company disconnects the call. This is usually but not always when the caller hangs up and the call appears to end.
> Voice calls The caller originating the call must hang up for the call to end. The person receiving the call may hang up, but this will not end the call unless the originating caller also hangs up. Only when the originating caller hangs up then will call charging end. You should always check you've replaced the receiver correctly. If you have any concerns that your call has not ended, you should check that you have a dial tone - this indicates the previous call has ended.
Here's a story from the shitty Register about this method of scamming people:
Wow, thanks for the clarification. That's incredibly stupid, I can't see the upside in that, aside from the telecom being able to charge more minutes per call (which is likely why it still functions that way.)