Shelly - DO NOT TRUST THE PHONE NUMBER YOU GET. Many phone calls you get nowadays should be treated as potentially suspect. This applies to your mobile as well as landline.
Here's why - Until recently only the telephone company could define what number was sent out as the calling id for the caller. Companies with PABXs could also define which number could be used to return calls. It was highly controlled. Criminals wouldn't go to the expense of installing PABXs and costly lines to spoof the phone number.
However, with new VoIP technology anyone can easily define what number callers see (including mobile numbers). I can spoof any number I like should I want to, even any international number should I wish to. It is incredibly easy to do. In 5 secs, I could be you!
This is organised crime and it is very difficult to detect. They expect you to trust information that previously was entirely trustworthy.
Many scammers use this nowadays for scam calls pretending to be someone else. They often make calls to numbers within the same code as they appear to send calls from. This gives the impression that that they are local to you so have some geographic relationship with you. You are more likely to trust them.
Worse, they often use numbers of legitimate businesses so if you check up, it looks ok. We've had many customers getting complaints from people saying that they've been called from their telephone numbers. When we've checked we can see that no such calls have been made.
My advice - Unless you you recognise the number calling, treat it as suspect. Either use a number you know, or, call back using the number they claim to be calling from. Scammers can't intercept calls you make (but see later). They won't use their own incoming number because that can be traced.
No business will call you and ask you to divulge any information with the exception of banks who may have legitimate reasons of security and fraud. In that case, they may ask you to go through security checks - but, of course so would any fraudster.
If you get a call from anyone claiming to be your bank (and potentially using the banks own number), either hang up and call back on the number you normally use, or, as I do just for a laugh, deliberately fail the security checks. If the caller (bank?) says you've passed, you know it isn't legitimate. Hang up. If they say you failed security you can explain you did it deliberately to prove they have the correct credentials to fail the incorrect ones you provided. Then hang up and call your bank...
Now - what few people know, is that there are (or certainly used to be) two caller ids sent on calls. The CLID that you are presented with can be spoofed, but, Network Caller ID which cannot. End users do not have access to that network id. However, the network providers do. They can, if pushed, use that for deeper investigation. Of course, most calls are now made using VoIP anyway - something that is invisible to you with a normal phone line. Not been in the business for many years, but I expect IP addresses to be used too.
New technology has made it easier to do many things that were impossible before. Sadly, it's also created an environment that allows criminal activity to occur and go virtually undetected.
Another scam that I believe has been closed, is the use of something called Called Party hold timer. They ask you to hang up and then call them back and pretend to hang up by going on to mute. When you redial they are still sat on the line and then pretend to answer. This service was to allow you to put the phone down and then pick it up again at a different extension. BT have removed this from their service configuration. As soon as you hang up, the call is cleared back so it forces the caller off your line. You should get dial tone when you try and call out.
