I have just had an incoming call, which I did not answer, from 31107 980010 (note the absence of an initial zero).  Does anyone have any idea as to the originator of this call?  Is it an attempted scam or just a format I have not encountered before?

Probably a genuine or spoofed Rotterdam number - +31 10 798 0010

Here you go: http://www.yer.nl/en-us/about-yer/offices/rotterdam/

Thank you for the information, just shows how important it is to group the digits correctly to aid identification.  This is the very first time an international number has been displayed on my phone, I usually get the message "Intentional" with no number displayed.
YER (a recruitment agency) are wasting their time with me as I retired fifteen years ago!  But it is nice to know that he call was probably not a scam.

The_Maluka wrote on Dec 9^th, 2014 at 4:32pm:

But it is nice to know that he call was probably not a scam.

Hmm, not so sure: https://www.facebook.com/LokalePolitieBlankenbergeZuienkerke/posts/802260213125668

The_Maluka wrote on Dec 9^th, 2014 at 4:32pm:

Thank you for the information, just shows how important it is to group the digits correctly to aid identification.  This is the very first time an international number has been displayed on my phone, I usually get the message "Intentional" with no number displayed..

You should no longer get International but get the caller's actual number prefixed 00 and then the country code and number following a recent requirement imposed by Ofcom on BT to provide this information on their landlines in return for their not considerable £16 per month line rental (although now of course you have to pay extra for Caller Display unless you take Anytime Calls).

The number you are getting appears to be a scam as I got 1614080000 on the CLI on my phone only a few days ago and this number does not exist!  Just another way for the scammers to bypass BT's useless Anonymous Calls Rejection systems, :o >:( :'(