Guide to Phreaking in London

LONDON numbers are all in the form:

1 2 3 4

X-XX-XXX-XXXX

Part 1: National Originate Digit (NOD)

0 - When dialling from within the UK otherwise ommitted

Part 2: London Region Code (LRC)

                81 - Outer London
                71 - Inner London

London is thus split into two separate regions, and hence has two main switch centres. Dialling other RCs will get other parts of the country (ie.061-Manchester).

Part 3: London Area Code (LAC)

000 -> 999

Part 4: London Subscriber Code (LSC)

0000 -> 9999

It is now obvious that parts 3 (LAC) and 4 (LSC) are going to be of the most interest in phreaking the system.

GETTING TO KNOW THE SYSTEM

Our first objective is to ascertain what all the LACs are from 000 -> 999. Quite a task. So we decided to list LACs that were not listed in the latest BT phone directories plus unusual ones that are listed (we mapped everything they hadn't mapped for us):

LACs in this section do not require NODs

          AREA CODE
100     - Operator
101-122
123     - Timeclock
124-141
142     - London Directory Enquiries
143
144     - BT Chargecard (Automatic)
145-150
151     - Faults
152
153     - International Directory Enquiries
154
155     - International Operator
156-189
190     - Telemessage Worldwide
191
192     - Directory Enquiries

193-199

201     - DEAD
211     - DEAD
216     - DEAD
246     - DEAD
264     - DEAD
282     - DEAD
285     - DEAD
292     - DEAD
296     - DEAD

344     - DEAD
345     - READING       LRC=81
362     - DEAD
363     - ENFIELD       LRC=81
369     - DEAD
396     - DEAD

400     - VOICEBANK / SEEMS TO BE DEAD ACTUALLY
442     - EDMUNDTON     LRC=81
447     - BARNET        LRC=81
448     - DEAD
484     - *** ENGINEER LINES *** : ALSORTS OF WEIRD BT FACILITIES! 1111=MODEM

503     - RODING

071-510 - POPLAR
071-513 - CANARY WHARF
-1111 NA

516     - DEAD
532     - DEAD
596     - DEAD

071-604 - MAIDA VALE
610 - *** WORKS BUT BT OPS HAVE NO RECORD OF IT ON THEIR COMPUTERS !!! *** 071-611 - FLEET STREET
071-612
612-1111 - Taussauds/crossroads?

614     - DEAD
617     - DEAD

618     - *** WORKS BUT BT DENY ITS EXISTENCE

- 1111 - CA 2400 - Prestel

619     - DEAD
649     - DEAD
652     - DEAD
662     - DEAD

705     - DEAD
710     - DEAD
713     - DEAD
715     - DEAD
716     - DEAD
717     - DEAD
718     - DEAD
719     - DEAD
762     - DEAD
765     - DEAD
797     - DEAD

810     - DEAD
811     - *** ENGINEER LINES ***
812     - DEAD
813     - DEAD
814     - DEAD
815     - DEAD
816     - DEAD
817     - DEAD
818     - DEAD
819     - DEAD
827     - DEAD
830     - DEAD
838     - DEAD
880-1111 - AA "Sorry you have got this machine, leave your
               name and number, and we`ll get back to you"

887     - DEAD
896     - DEAD

910     - DEAD
919     - DEAD
926     - WHITEHALL     LRC=71
939     - CITY AREA     LRC=71
966     - HULLSTON      LRC=81  OPERATOR SAYS IT HASN'T OPENED YET
970     - DEAD
990     - WEMBLEY       LRC=81
996     - DEAD
999     - EMERGENCY

It was obvious from this scan that BT had some nice little exchanges in London that weren't intended for public use - so we just had to use them! Here are the exchanges that we felt required some more thorough examination:

484     ENGINEER LINES
610     BT DENY THIS EXCHANGE EXISTS - NO ACTIVITY HERE YET
612     BT DENY THIS EXCHANGE EXISTS - NO ACTIVITY HERE YET
618     BT DENY THIS EXCHANGES EXISTENCE - AND THERE'S A MODEM ON 1111
811     ENGINEER LINES
926     WHITEHALL - THIS ONE BECAUSE IT MAY BE PRIVATE WHITEHALL LINES (PM ETC.)

These are the ones to start with. We aren't completely satisfied with some of the others. Perhaps BT have just put them in - we'll find out in the next phone directory. So if some of these seemingly ordinary exchanges aren't ordinary at all, what makes them so special that BT have to cover them up? - we`re sure gonna find out......