@gmarkj wrote:
After this time it indeed goes back into the pot waiting to be used.
This got me thinking about exactly how mobile numbers are allocated - clearly geographic numbers are allocated (somewhat) by geography - chances are if you get a call from a number starting 01773 it's likely the caller lives in Ripley..
However cellular no's are non-geographic eleven digit numbers and are allocated by the first six digits ONLY company by company, by ofcom.
Soo here's how i think it happens, take the number.
071060XXXXX
07 - Digit one & two designate the number as being a personal number, a pager, or a mobile number.
1 - The third digit if it is 0 indicates a ten or eleven digit 'personal number' **** and if its a 1 thru 9 then it's a mobile or pager number
060 - Digits four, five and six are together with digit three are either allocated to a provider or reserved for future use. O2 have 1060 thru to 1079 ie 071060 00000 thru to 071079 99999
XXXXX The last five digits are up to the company to allocate...
So just in the number range listed alone the company has or at least had a million numbers to choose from - all in all Telefonica alone probably have or HAD number ranges in the 20-30 million individual numbers.
I say 'had' cos the bottom line is you can only have any one individual number in use uniquely. Once it's been allocated on a sim, or in use by a customer or has been ported out of the network it's no longer available.
Now the ofcom list I looked at, for all this, lists every one of the 070 personal number prefixes including 07005, 07006 and 07008 but strangely 07007 is missing - showing that even ofcom know the value of certain number ranges.
I'm guessing the networks horse trade their own ''desirable" numbers with other networks 'desirables' cos many number ranges will be valuable to some customers but not to others but I expect they keep the most valuable ones to sell off, as gold.
Additionally and has been mentioned numbers that some might consider desirable that end up on PAYG sims can be sold on by third parties, though using these involves activating/ taking over the SIM, and then porting it in if wanted on a contract.
Quite how they keep track of the desirable needles in the haystack of bog standard numbers is beyond me, and the above just points to the futility of trying to track down 'in use' numbers. Either a number is available to a network from its own stock or another networks in which case might be allocatable or it's been allocated and it isn't.
***** often called '070 personal numbers' or “follow-me” numbers, 070 numbers are used to connect calls to landlines or mobiles with the caller paying all connection costs.
