JoeCz wrote on Nov 3
rd, 2007 at 2:03pm:
...goodness me, that IS a lot.
I'll start trying those when I've finished my current assignment, perhaps
Thanks a lot for your help so far, it's much appreciated.
07/1994 is the earliest date on
any prefix (including BT), so I would take it that these numbers existed before then.
I'd definately try the later ones first. You might try each prefix and substitute the 'f-digit' (like I suggested with 0161 279) with 0 through to 9.
There aren't that many allocated since 2000, so I would try them with the last four (or three for 271) digits of your extension. Then I would go through and substitute the f-digit with numbers 0-9 which you haven't tried thus far.
Bear in mind that if someone answers (and this is true if you do it outside business hours) that it is probably
not a business line you have dialled. That doesn't mean it
is student accommodation,
but those NTL (Virgin Media) residential (cable) lines are likely to not be part of a block of numbers.
For the student accommodation there is presumably a large block of consecutive numbers, eg 0161 234 5000 through to 0161 234 5199. A residential line needs just one number (not part of a group of numbers) and there's likely to be free numbers within those older prefixes. For this reason, if someone does answer out of business hours on one of those 2000-onwards prefixes, then make a note of it.
It's all detective work, ifs and buts. I can't say that you will definately find the number, but going by the assumptions I've explained here, then hopefully you can eliminate some of the less likely numbers.