Missed calls appearing but BT cordless phone does not ring for those calls

[#1]

We recently bought a set of three BT Advanced Phone Z cordless phones with answer machine and call blocking facility. When someone who is actually on our contacts list gives us a call, the phones ring properly as expected and we can pick up the call. However, we've noticed that whenever anyone NOT on our list has tried to call, the phones have not rung and there is a missed calls notification on the display. There was no voicemail left. The answer machine facility is set to ON, but of course as the caller is unknown, we have no way of knowing whether or not they tried to leave a message. The call blocking facility is set to OFF (although it had been ON for a while initially).

Does anyone have any idea what might be happening here? Is it the phone or the phone network that's at fault?

[#2]

@Rob15 You will probably find that 99.99% of these missed calls with no message left  are robo-calls, where a machine dials a long list of numbers in the hope someone will pick up and probably fall for a scam. Because these are machine-dialed, as soon as the answer machine kicks in, the call is dropped.

There is nothing wrong with your phones - they are doing what they are designed to do -prevent dodgy calls, and nothing wrong wth the phone network, either.

[#3]

Moderator's note(s):

Thread moved from Home Phone to Tech Help.

[#4]

Hi John, thanks for the reply.

I'm curious to know how the system can differentiate between machine dialling and human dialling. And is the system actually the phone network or the answer machine in the phone?

Rob

[#5]

@Rob15 I'm not a telephone systems expert, but the auto-diallers these scam merchants use must have something in their circuits/electronics that can identify when the call is diverted to an answering machine - it is amazing what can be provided with electronics. It is not the phone network itself that makes these decisions.

[#6]

If it's the phone that decides, then I'm surprised that there's no setting in the phone to switch this on or off. After all, some machine-dialled calls may be legitimate. For example, in many offices, people's PCs are linked to the company's phone system, so they can dial out to their customers via an app rather than using an actual phone.

You would expect to see such a setting somewhwere within the Call Blocking feature. However, as I mentioned before, I have switched this off, but the filtering is still occurring.

Rob

[#7]

@Rob15 I don't have a similar phone - I just rely on a simple one that shows the callers number, and decide whether or not to answer it myself.

Maybe someone with one of these fancy phones will be able to advise you better.

@bmc - any thoughts?

[#8]

On re-reading your post above, I suddenly realised that what you probably meant was that the decision-maker for clearing the robo-call would be the calling system rather than the system receiving the call. If that's the case, then you would expect that our phones would still ring before the call is diverted to the answer machine. However, we know that there's no ringing with those missed calls, so the reason for the problem must lie within our phones themselves. It just seems that the Call Blocking OFF setting is being ignored, and that callers not on our contacts list are still being placed on the block list.

Rob

[#9]

As I said, I don't know how these phones with internal call blockers work, but I understand the calling party has to respond to a message, generated by the call-blocking system, before the call is passed to your phone to make it ring - if the calling party doesn't respond, as these auto-diallers don't, then the call is dropped, but obviously registers on the call log - in case you wanted to reply - but I wouldn't bother.

[#10 · Accepted solution]

Managed to fix it by simply resetting the base unit - so it was just a software glitch!