Different CLIs for same telemarketing call

InsideInsurance

I only have a basic understanding of how the telephone system works and so would appreciate someone with more knowledge explaining something for me.....

I often receive phone calls on my mobile from a particular telemarketing company and the number that my mobile shows is a whole range of 0161, 0141 numbers etc which I understand.

My network provider however also sends me a text each time I dont answer a call advising I've had a missed call from X number. The odd thing which I dont understand is that when I get a missed call from this company I always get the same 01872 number in the text.

So basically they are managing to tell my mobile its one number but my operator its a different number. How is this happening?

Nik_Doof

What you'll find is that they're sending out those random numbers as their CLI (which can be set by the caller if they're using a PBX or other large switchboard), but the network is sending you the underlying number, as in the phone number for the underlying line they're using to call you from.

I think the Wikipedia article might explain it a bit better than me

Lum

Basically when you make an outgoing call, you can set Caller ID (the number that is displayed on your phone) to whatever you want.

What you can't change is the actual number you are calling from which is needed for the various telephone companies billing systems.

Naturally the telcos don't care if you get given a fake number, but they can't be having fake numbers in their billing system as then they may not be able to charge for the call.

The text you are receiving uses that second number.


Note that there are legit reasons for sending fake caller IDs, for example it is impossible to make a call from an 0800 number, but you may want to present this number to your customers so that they don't get charged when returning the call.

railbuff

they will be using a service like flextel.

for my business i use a mobile phone, but these can be expensive to call from landlines, so i have a 0191 number from flextel the redirects to my mobile, but this means that anyone calling my business from a landline only pays the std LL to LL call rate and not LL to mob rate. the 0191 number is the number that will be seen if i use a particular code at the beginning of any call i make from my mobile.

InsideInsurance

Many thanks for the replies....

I understand the need for setting different CLI's but I wasnt aware that there was an underlying number in addition to the CLI

Is there anyway to get the underlying number to show on a mobile/ caller display rather than the CLI or is this something filtered out by the time it goes through your network provider?

Lum

There is no way to see that number unless you work for the phone company or have a court order.

InsideInsurance

As I say, I do see "it", its what they put in the txt for the missed call alert.... was just hoping to get it before decide if to answer the call or not as its static -v- the caller ID which changes with every call

I say "it", all i know is I send the call to voicemail and then always instantly get the txt to say I've just missed a call and it is always the same Turo based number -v- the caller ID number which can be a manchester, glasgow etc number. Of cause it could be an amazing coincident that everytime a caller from this company phones another of their associates also tries to call from a different office but then I never receive a miss called text from the other number

Lum

Yes, that one is odd and shouldn't really be happening.

Which provider is it? That is quite a useful bug

InsideInsurance

O2 .