London phone numbers

[David H]

By adding an eighth digit, the capacity for London numbers was increased by ten. But has anyone an estimate of how long it could be before a third extra starting number is used apart from the current 7 and 8 (as in 020- 7*** **** and 020- 8*** ***)? The change has so far only doubled the capacity, and I can't imagine when we would need to extend the current capacity of up to 200 million (less the various unusable numbers of course) by an extra 100 million each time.

[gilf]

Remember that its not just home phone's were talking about. Take for example a new office block 25 floors 200 people per floor thats 5000 phones just in one building. Add into that data lines for I.T. etc and the numbers start to build up. Also take my company for example all our numbers start 01304 863 etc therefore we have effectively reserved 1000 possible numbers (we may not have but they do run in sequence so I would assume we have reserved some capacity for expansion). One final thing is to remember that they are split by exchange so a code of 020 8850 may only use 2000 of its numbers but another may use its full compliment (normally dealt with by adding another area code) which again are limited, what I mean is that not all numbers need to be in use for you to in practical terms run out of numbers in a specific area. I'm not sure of the impact of digital exchanges but the old analogue physical exchanges passed things around in physical terms meaning you couldn't give a lewisham number to a phone in putney for example, I think from a point of continuity this would remain but no longer be a physical restriction.

[David H]

Obviously another telephone enthusiast here, yes, I realise it's all the data that needs the extra numbers, I have one here as well. Sadly, with non BT numbers, we don't have area codes being allocated non-area codes, which I think America did to save them adding the annoying 8th number we borrowed from (who else) the French (and Australians). With a country the size of Europe (at least) plus Canada and the West Indies, they have managed to retain a national 3 plus 4 local code throughout, and the area codes have enough capacity for now as well. What we do have in London are 'area wide' non BT exchanges. That means for instance 8933 has no official area, just outer London. But in fact, they all relate to local areas, as my cable bill allocates an accurate location to all their own exchanges, but for some reason, they are never listed publicly. You get to know them by default when you see eg a batch of 8296's in Richmond, but non BT operators outside London are given towns but do not, unlike BT, divide into suburbs so your 863 should relate to the main part of the town beginning with D, but a similar cable number could be anywhere within the 01304 exchange. You can probably tell I've studied this sort of thing for some time!

[David H]

I missed a sentence there- it should read 'they don't allocate out of area codes within local London exchanges, but sadly the cable companies do not use local areas at all officially.' 'edit my post' function.