"no number" calls

[azc60]

I have started to receive calls that display as "no number". What are these (specifically, I get the general idea!) and why am I getting them now when I never used to?

[licquorice]

They are scam callers, probably scammers trying a new tactic.

[azc60]

Not necessarily the case. We normally ignore unrecognised numbers, but have had several of these "no number" calls lately. When we actually answered one of them it was a call from a number we knew and would have automatically answered if the actual number had been shown.

We also have been expecting a reply from someone we left a message with but have not had one, and now we are suspecting that some of these "no number" calls may have been that number.

So my original question stands. What, specifically, does this flag mean? The wording implies it is different to "number withheld" and is perhaps a new "service" a caller can request.

Scammers already have a variety of options to disguise themselves, and I doubt they would use a technique like this as it actually encourages the recipient to ignore the call, unlike all the usual tricks of number spoofing, temporary numbers and so on.

[licquorice]

That would imply that the calling number is not being generated correctly by the calling provider rather than being deliberately withheld. Do you know the service provider of the caller you answered?  I can't imagine it is a service offered to customers.

[azc60]

No idea. And the one we did answer is a business so the chances of getting that information are close to zero.

I goggled around a bit on this and there has been some suggestion that this can arise when a contract is renewed, as ours has just been. But our renewal only started on the 24th Feb and we've been seeing this type of call for a couple of weeks at least.

I do vaguely remember being offered an option on our renewal that was something along the lines of "always hide your number when making calls" and so I wonder if these "no number" messages are what the recipient sees if the caller has taken that option (rather than the previous "withheld" message)