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uk.telecom FAQ, Part 1/3 - Questions, and Contacts.

( Part1 - Part2 - Part3 )
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Archive-name: uk-telecom/part1
Posting-Frequency: monthly
Last-modified: Time-stamp: <96/06/16 14:53:00 jrg>
Version: 2.11

See reader questions & answers on this topic! - Help others by sharing your knowledge
               Frequently Asked Questions for uk.telecom

                    Part 1 - Questions and Contacts

        Compiled/ Posted by James Grinter <>

These articles attempt to summarise answers to some of the more often
asked questions in the newsgroup uk.telecom.

This first part of the Frequently Asked Questions (FAQ) summarises the
questions, and gives places to go for further information.

See also below for details of the uk.telecom archive, or the find the
regular post to uk.telecom.


This post, and all other periodic postings to news.answers are
available for anonymous ftp in the periodic posting archive [], or via E-mail by sending a
message to <> (send a message with "help" in
the body to get more information).

This is mirrored at <URL:>.

This FAQ is also available in a simple hypertext form on the World Wide
Web at <URL:>

Other FAQs are available on the World Wide Web at


[Compilers Notes are in square brackets (like this)]

Comments / Contributions **always** welcomed with open arms either on
the newsgroup or via email :-) -- james.

   This information has been culled from postings to
   uk.telecom, mail and occasionally from files of the 
   comp.dcom.telecom archive. I give no guarantees of
   its accuracy etc.. I also reserve the right to edit
   postings for length and relevance.

   **Please**, only use any prices as a guide - if you want
   up-to-date pricing information contact the relevant
   people. (many numbers are listed at the bottom of 
   this article)

   My thanks to all those who participate in the uk.telecom

   **Special** thanks to the original compiler of this FAQ, 
   Christopher Samuel <> - his
   name has moved to here so that people don't keep troubling
   him with regards to this FAQ!


Subject: Part 2 - Telephone Service

  Subject: What is uk.telecom ?
  Subject: Phone numbers
    Q: Why do we need another digit in the phone numbers?
    Q: So who decided, and what were the choices? 
    Q: Who owns this numbering space ?
    Q: I've heard someone mention about Mercury's 0500 service, what is it ?
    Q: How can I phone American 1-800 (toll free) numbers from the UK ? 
    Q: How do I dial a number with a mnemonic in it ? 
    Q: What are BT Phonebase/ Electronic Yellow Pages/ TeleDirectory and
       how do you get access to them? 
    Q: What defines a local call area?
    Q: When did the National Code Change take place? 
    Q: When did the International access code change happen? 
    Q: I want a new line with a particular number, or want to renumber an
       existing line to a particular number.
    Q: What sort of dialling code is <x>? 
    Q: What codes are free to the caller? 
    Q: How should I correctly write my telephone number? 
    Q: What is a "DE block"? 
  Subject: Oftel
    Q: Who or what are OFTEL? How do I contact them?
    Q: Do OFTEL set any of BT's charges?
    Q: How do I get a copy of 'Oftel News'?
  Subject: ICSTIS 
    Q: Who or what are ICSTIS? How do I contact them? {*}
  Subject: Mercury Communications Ltd
    Q: Can you use a Mercury 131 account from any phone? {*}
    Q: What is the Mercury beep, and can I get rid of it ? 
    Q: What do I get on Mercury's itemised bill using cost centres? 
    Q: Is it possible to access Mercury 131 from a BT Payphone?
    Q: How can I dial 9 digit numbers quickly- the system waits a
       while for the 10th digit?
    Q: What is the Mercury 132 service? {*}
    Q: Can I tell if Mercury 131/132 service is available in my area? {*}
    Q: Can I use 132 service from multiple exchange lines? {*}
    Q: How do I get Mercury's price list? 
  Subject: British Telecommuncations plc (BT)
    Q: Why is there no 0345 access to PSS Dialplus ?
    Q: What **are** these Network Services that people keep mentioning?
       Are they a BT version of teletext or something? Do you have to
       pay for them?
    Q: When I use call waiting, and press R to get the dialling tone
       so that I can get to the new caller, nothing happens i.e.  no
       dialling tone.
    Q: How do I order BT's full price list ?
    Q: How do I get a BT 'Midnight line'? 
    Q: Are calls made on Midnight lines **outside** the Midnight-6am
       free period charged at normal dialled rates?
    Q: Can I get a fully itemised bill from BT ? 
    Q: How can I get ISDN? 
    Q: What are the costs of ISDN connection and calls? 
    Q: What does an 0990 number offer you, and what is its cost? {*}
  Subject: Caller ID/ Caller Identification (CLI/CLID)
    Q: Is Caller ID available in the UK ? 
    Q: What PSTN phones support Caller ID? 
    Q: What ISDN phones support Caller ID, decoding and displaying it?
    Q: I've seen a couple of ads in Exchange & Mart for Caller ID devices...
       anyone know if these really work ?
  Subject: Call barring
    Q: Will BT provide a line with all outgoing calls disabled except
       to Mercury?
    Q: Is it possible to bar reverse charge calls on a line that
       allows incoming calls?
    Q: What are the newly announced plans for barring 0898 Adult 
       Entertainment premium-rate numbers? {*}
  Subject: Engaged lines
    Q: If someone's number is permanently engaged, what can you do? 
    Q: What can BT do about a phone off the hook?
  Subject: Automatic announcements
    Q: What are the meanings of the various automatic announcements? {*}
    Q: What are those 'Doh dah dee' tones? 
  Subject: Chargecards
    Q: I want to get a BT Chargecard, the problem seemed to be that
       you need to be a current customer (have a phone) to be able to
       get one.  Is this so?  If it is why is it so?
    Q: Why can't I direct dial with my BT chargecard on Cellnet ?
    Q: What itemisation do I get with a BT Chargecard?
    Q: What service do you get with the Mercury Calling Card? 
    Q: What service do you get with BT's Chargecard
  Subject: Other Telephone services
    Q: What is AT&T Direct ? 
    Q: What is Flextel?
    Q: What ways are there of calling the US cheaper than BT or Mercury?
    Q: Who are ACC? 
  Subject: Facsimile/ FAX machines
    Q: Where can I get a FAX switch from?
    Q: What is the legal status of messages transmitted via Facsimile? 
  Subject: Radio Pagers
    Q: What are recommended pager companies in the UK?
  Subject: Cellular/ Mobile phones
    Q: I was recently offered a "free" Cellphone with a product I
       bought. While I accept that it may be a condition of accepting the
       "free" phone that you also subscribe to their airtime, is it
       actually _illegal_ not to purchase an agreement with the phone?
    Q: Will calls from PSTN lines to mobile phones, in other
       countries, work?  What premium will I pay above the normal
    Q: Will inbound access to UK mobiles work?
    Q: Where can I get details of Cellnet, Vodafone, One2One, and Orange
    Q: Why do analogue cellphones have a 'soft' serial number,
       enabling alteration?
    Q: What do Cellnet Callback and Vodafone Messenger offer?  Who do
       I ring for help?
    Q: What prompts the Cellnet callback or Vodafone Messenger
       systems to call back?
    Q: Who are the 'People's phone'?
    Q: How can I check the status of a GSM or PCN phone's divert and
       call waiting? 
    Q: What facilities are present in GSM and PCN handsets (like Orange and
       One2One) to counter 'phone thieves? 
    Q: What are the functions possible with Hutchison's Voice messaging
    Q: What are the phone numbers for the GSM network SMS 'message
  Subject: Phone Call charges
    Q: Why are some numbers charged for when they don't exist?
    Q: What are the costs of running 0345 and 0800 number services?
    Q: What are the current phone-call costs? 
    Q: What is an 'average' 'phone bill for the US, as a comparison?
    Q: So how do the Americans price their 'phone calls then?
    Q: What happens with the cost of calls which last over two or more
       charge bands?
  Subject: Other Telecoms info
    Q: Where can I get an old style BT phone box from ?
    Q: So tell me some more about these old phone boxes 


Subject: Part 3 - Technical matters

  Subject: How do phones work?
    Q: Okay, so tell me this. How do phones work ?
    Q: Where can I get technical information about UK telecommunication
    Q: What do those wires do?              [last update 27/3/95]
    Q: Why a third wire for the bell?
    Q: What's this about master sockets and lineboxes?
    Q: My equipment (telephone, modem, computer...) has an RJ11 socket
       for connecting the line cord.  What are the connections?
    Q: Does it matter if A and B are interchanged?
    Q: Why that 470 kohm resistor in the master socket?
  Subject: BABT
    Q: Who or what are BABT? How do I contact them?  
  Subject: PSTN
    Q: How can I simulate the PSTN? 
  Subject: PSDN
    Q: What is the PSDN?
  Subject: ISDN
    Q: What is ISDN?
    Q: What are the costs of ISDN connection and calls?
    Q: Say I want to access my University computer from home, using an
       ISDN connection, in order to get fast terminal access and file
       transfer.  What would I need to connect a PC to a Workstation
       over this? 
    Q: What's the difference in equipment at the exchange switch between
       an ISDN line and that for an analogue line? 
  Subject: Leased lines
    Q: We ordered a 14.4k leased line, and BT are installing a 64k
       line with convertor. Why, and surely it costs them the same?
  Subject: Exchange features
    Q: Is it possible to set up a three way call, then have one of the
       other guys introduce another caller.. ad infinitum?
    Q: How does Caller ID Work? 
    Q: I hear that PABXs with two or more incoming lines require a 
       maintainance contract.
  Subject: Telephones
    Q: Why does my pre-socket phone 'tinkle' in the night ?
    Q: What is the difference between Timed Break Recall (the Recall button)
       and flashing the hook?
    Q: How does the BT Chargecard system work ? {*}
  Subject: Modems
    Q: I use Network Services to bar incoming calls, but when the
       barring is inforce, the dialtone is different, and hence my modem
       won't autodial.  Is there a way round this?
    Q: Can you use ordinary dial-up modems over a leased line?
    Q: How can I use my analogue cellular phone with a computer modem? 
    Q: Can I use a modem with GSM/PCN? (otherwise known as "Can I get
       free internet access on Mercury One-2-one?") 
    Q: I'm having a problem with my modem. Intermittently it fails to
  Subject: Faxes
    Q: How do FAX switchers work?
  Subject: Answering machines
    Q: How do I stop my answering machine recording the "Please
       replace the handset & Try Again" message when someone hangs up
       without leaving a message? 
  Subject: Radio Pagers
    Q: Is it possible to use a computer and modem to send messages to
       UK pagers? 
  Subject: Cellular/ Mobile phones
    Q: What are the new digital phone networks capabilities for data
       communications? [ie. Can I use my One2One/Orange phone?] 
    Q: What do One2One PCN aerials look like?
    Q: How do mobile phones work in tunnels
    Q: How does the network find the mobile phone? 
    Q: How does the network distinguish between 'switched off' and 'not
       responding' when giving messages to the caller? 
  Subject: CT2 (Phonepoint, Hutchison Rabbit, etc)
    Q: How do I unlock a Hutchison Rabbit handset?
    Q: What are the little switches in a rabbit handset battery
       compartment for?
    Q: Where can I get batters for a Rabbit handset from? {*}
  Subject: Telephone exchanges
    Q: What types of exchange are there, and which can be digital ? 
    Q: What is the difference between a System X and System Y exchange ? 
    Q: What is the number that will dial my 'phone back to test the
    Q: When I called 175 from home there was a message telling me my
       phone number, then when I hung up I was called back and offered a
       mysterious menu.  Anyone know how to work it?
    Q: What do the various messages from the 175 tester on System X really
       mean, eg. "Earth A, Battery B"?
    Q: Is there a way I can pulse-dial a digital exchange number and then
       tone dial from there? 
  Subject: International calls
    Q: How do I get a guaranteed non-satellite circuit to the USA ?
    Q: Is non-satellite link to the US helpful when using transfer protocols
       such as XModem?
  Subject: Phone numbers/ DTMF 
    Q: What are the frequencies for DTMF (Dual-tone multi-frequency) digits?
    Q: How can I identify a 'phone number from a recording of the DTMF digits?


Subject: Where can I get further information from ? 


There are several other telecoms related newsgroups which I am aware
of .  The two main ones are comp.dcom.telecom and but be warned, they tend to be dominated by US
specific items, and the first one is moderated as a gatewayed digest,
so articles MUST be submitted to the moderator for approval.
(Submissions: <>, requests to telecom-request at
same address). Look also at alt.dcom.telecom.

FTP/ Telnet/ Mail:

There is a uk.telecom archive at Imperial College in
<URL:>.  It contains both an
archive of the group in volume92/, volume93/, etc with an index by
subject in the file Index, and a small collection of useful files in
the 'archive' directory, including some versions of the FAQ and the
network services posting. Some of the 'archive' directory is currently
a little out of date.

For anonymous FTP, the Usenet newsgroup comp.dcom.telecom has an archive
site at [], with a quite comprehensive suite of
files, including some UK specific stuff. This and the uk.telecom
archive is fully mirrored at <URL:>.

Adrian Savage's 'UK Telecom Information Source', with details
of UK telephone operator tariffs. <URL:>.

Telecoms information, including an on-line version of all the National FM
(i.e. not Local or AM) transmitters, derived from BBC and other
enigineering information. <URL:>.

A list of UK STD area codes is available from
<URL:>.  [This list is not currently
being maintained]

A list of 0800 and 0500 numbers is available from
<URL:> and from
<URL:> - a list in Freephone
number order and <URL:> - a list
by Category.

 Tim Clark, at Warwick University, has some useful collections of phone
information, including UK Telephone National Number Group codes
(NNGs), and 'Oftel Specified Numbering Scheme'. see

Mailing lists:

Phone card collectors mailing list: subscribe with mail saying 'subscribe
phonecard-collectors Your Name' to <>. Messages **to
the list** are sent to <>.

iSDX managers mailing list: Requests for inclusion/deletion should be sent
to <> (message body 'subscribe isdx'). 
Submissions sent to <> will be reflected to the list

Orange users mailing list - subscribe with 'subscribe orange' or
'subscribe orange-digest' to <>, list is at
<>. An archive of the list is kept at

Other WWW resources:

ITU archive, <URL:gopher://>, <URL:>.
OFTEL        <URL:>
ICSTIS       <URL:>
 charging    <URL:>


You could try BT, or Mercury direct, if you really want to.

[Thanks to Kevin Hopkins <> for most of these numbers]

For BT enquiries the phone numbers are

                                 BT Line   Any Line
   Residential General Enquiries   150    0800 800150
   Residential Fault Reports       151    0800 800151
   Business General Enquiries      152    0800 800152
   Business Fault Reports          154    0800 800154
    (and billing enquiries)

   Iain Vallance's office (direct)        (0171) 356 6666

   Recorded advice line            ---    0800 666700
    (basic information and further BT contact points)
   Welsh language advice line      ---    0800 663388
   Reporting Malicious calls       ---    0800 661441
    (to BT's specialist bureaux)
   General BT enquiries            ---    0800 212950
    (Personnel, Schools' Liaison, Media etc)

   Telephone preference service           0800 398893

   BT news line                    ---    0800 500005

For Mercury enquiries the phone numbers are 

   General Enquiries                      0500 500 194
    Business                              0500 700 101
   Fault Reports
    Residential                           0500 500 193
    Small Businesses                      0500 700 103
    Large Businesses                      0500 424 193
   Billing Enquiries                      0500 500 196
    Business                              0500 700 102
   Operator Service
    for Disabled Customers                0500 500 195
   Customer Relations                     0500 500 197

   YourCall Scheme                        0500 200 930
   Calling Card Info                      0500 100 505

   Telephone preference service           0500 398 893

For some of the other carriers and services

   ACC            0800 160 111
   AT&T        (0171) 925 8000 (uk head office switchboard)
    General enq.  0800 064 0001
    'Direct'      0500 89 7801
   Energis        0800 161600
   Ionica         (01223) 223000
             Fax: (01223) 223100
   ICSTIS         (0171) 430 2228
                  0800 500 212 (complaints only)
   MCI:           0800 89 0222
   Sprint:        0800 89 0877
   Swiftcall:     (0171) 488 2001 (Visa/ MC required)

   Mercury One2One    0500 500 121 (sales)
                      0958 121 121 (customer services) 
                      956/ 0956 956 956 - Talking Guide Book
    (C&W/ USWest owned company)
   Orange plc         0800 286 286 
                      0973 100 150 - customer service
                      (01454) 624 664
   Cellnet/ Lifetime  616/ 321
   FleXtel            0956 700 700 (sales)
   Hutchison Pagers   0800 59 00 59

   Vodafone directory enquiries (available from abroad, sometimes..)
                  +44 836 192 192

Cable information 

   Aberdeen Cable           Aberdeen            01224 633633
   Andover Cablevision      Andover,            01264 332300
   Anglia Cable             Harlow,             01279 867867
   Birmingham Cable         Birmingham          0121 628 2828
   Cable Corporation        Windsor             01753 810707
   Cable London             North London        0171 911 0911
   Cable Midlands           Wolverhampton       0500 838485
   Cable North West         Liverpool           0500 500150
    CableTel                 Surrey and Hants, West Central Scotland,
                            South Wales, Beds and Herts, Kirklees,
                            & Nothern Ireland   0800 602 603
   Cablevision Bedfordshire South Bedfordshire  01582 401001 
   Cambridge Cable          Cambridge           01223 567567
   Coventry Cable           Coventry            01203 505070
   Diamond Cable            Nottingham          0115 952 2222
   Encom                    Tower Hamlets       0171 363 3000
   Bell Cablemedia          Watford             01923 464646 
   LCC Cable                Leicester           0116 233 4000
   Metro Cable              Welwyn Garden City  01707 336844
   Norwich Cablevision      Norwich, Norfolk    01603 787892
   Nynex                    Bromley, Derby, Solent, Sussex, 
                             & Surrey,          0345  114455              
                            Bolton & Blackburn  01204 365440
   Peterborough Cablevision Peterborough        01733 230303
   Swindon Cable            Swindon, Wiltshire  01793 615601
   Telecential              Hemel Hempstead     01442 230444
                            Northants           01604 494949
                            Reading & Bracknell 01734 755155  
   United Artists           Avon                01454 619666
					        0500 600150
                            Cotswolds           0500 532222
                            Croydon             0181 781 0555
                            Dundee              01382 22220
                            Edinburgh           0131 539 0000
                            Glenrothes          01592 630430
                            London South        0181 781 0555
                            South East          01268 470000
                            North East          0191 420 4000
                            Motherwell          01698 810827
                            Newcastle           0191 420 4000
                            Perth               01738 38794
   Videotron                Southampton         01703 315315
                            South & West London 0181 244 1111
   Westminster Cable        London              0171 935 4400
   Yorkshire Cable Group    Bradford            01274 828200

Mandarin Technology:

Another source of information are Mandarin Technology, who have told us
that they do try to help anyone needing more telecom-based information,
especially in the regulatory fields, and are equally happy to respond to
enquiries received by voice, fax or email.

Details (pinched from Richard Cox's .signature) {*}

Mandarin Technology, P.O. Box 111, Penarth, South Glamorgan, Wales:  CF64 3YG
Telephone: 09733 111111;  Fax: 09733 111100;  VoiceMail: 09411 515151
E-mail address: - PGP2.3 public key available on request

Wish List:

1) UK versions of comp.dcom.telecom archive files.

2) People emailing me with all those corrections to this info.

Thanks section:

This FAQ would not have been possible without contributions, help and
support from the following people (Richard Cox), (Keith
Mitchell), (Tim Oldham), (Graham
Allan), (John C Sager), (Tim
Clark), (Syngen Brown),
(Brian N Butterworth), (Malcolm Ray), (Stephen Hebditch),
(Chris Davies), (Gavin Spittlehouse), (Robin Fairbairns),
(Ranald Mcintyre), (Keith McNeill), (Mark Whalley),
(Tony Fisher), (Shakib Otaqui), (Gary Kendall) (Roy Badami), (Roger Browne), (Paul
Martin), (Peter Whisker), (Dave Plumb), (Steve
McKinty), (Kevin H),
(Nigel Titley), (Neil Todd),
(Gareth R.  M. Davies), (Janusz Lukasiak), (Tim Steele), (Mark Rogers),, (Graham Wilson), (George Zmijewski),
(Phil Houseago), (Martin Cook), (Rick Payne), (Alan J
Flavell), (Kevin Holley), (Stephen Page),
(Russell Whitworth), (Ian Hastie), (Phillip Coathup), (Frank
Erskine), (Jonathan Cohen), (Chris Boots),
(Barry Chatfield), (Allan G Carr).

and all the readers/ posters to uk.telecom, especially those 
who (unfortunately) come in for a lot of flak because of their employer's
sometimes odd actions.  Keep posting!

[end of uk.telecom FAQ part 1/3]

User Contributions:

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Last Update March 27 2014 @ 02:12 PM