The British Post Office (BPO) purchased telephones and other apparatus from various manufacturers.  On a lot of equipment the manufacturer can be identified by the use of a manufacturers code.  Where a PO factory code is shown, that means that the equipment has been made or refurbished by one of the BPO factories.  Quite often these codes are on labels stuck over the top of the original manufacturer’s code.

It is clear that the original single-letter and later double-letter codes were allocated with fairly little regard to any logical meaning.  Once all codes were expanded to at least three letters greater care was taken to make meaningful combinations.  Existing two-letter codes were expanded by suffixing 'A' to the original code.  The list also includes some non-BPO codes commonly found on telephones (AP, YA and Z).

Thanks to many articles from the Telecom Heritage Group, especially the lists compiled by Graham Wooten, Andy Emerson, BT museum and John Ferris.

Code   Manufacturer

A                 Edison Swan Electric Ltd. 

AA              Pinching & Walton


A9W           Trench & Manhole Covers Ltd

AAG           Mullards Ltd - London SW18

AB              A. C. Brown

AC              Nalder Bros. & Thompson

ACL            Advance Electronics Ltd.  Hainault, Essex.

ACW          AVO Ltd - London SW1

AD              Spagnoletti (see CN)

AE               Medical Supply Association

AEK            GEC-AEI Telecommunications, Kirkcaldy, Fife, Scotland

AEG            GEC-AEI Telecommunications, Glenrothes, Scotland

AEY            AEI Telecomms Group - Worsley Bridge Rd, London, SE26

AEP            Automatica Electrica Portuguesa (not a BPO code - found on phone - see Plessey)

AF               Armstrong Bros.

AG              H.W. Bolt

AH              J.H. Tucker & Co.

AJ               Consolidated Supply Co.  

AK              Peel-Conner Telephone Works Ltd - became GEC

AKA           Sterling Telephone & Electrical Co. - Dagenham, Essex

AL               W. Robinson & Co. Ltd.

AM             Wrench Mfg. Co.

AN              E.F. Moy Ltd.

ANS            Ansaphone Ltd - Camberley, Surrey

AO              Beck & Co. 

AP               King & Scarborough

AP               Admiralty Pattern (British Navy). Not a BPO manufacturer code.

AQ              Gambrell Bros.

AR              Houghton Ltd.

AS               Noakes & Sons

ASW          Armstrong Stevens & Sons - Willenhall, Staffs.

AT              McMillan & Co.

ATB            Automatic Telephone & Electrical Co. Ltd - Bridgnorth

ATL            Austin Taylor Electrical Ltd - Bangor, N. Wales

ATK           Plessey Telecom Group - Kirby Industrial Estate, Liverpool

ATL            Austin Taylor Ltd - Bangor, N. Wales

ATW          Automatic Telephone & Electrical Co. Ltd - Wigan, Lancs.

AU              J. Russell & Co.

AUC           unknown

AV              Tylers Ltd.

AW             W. & F. Dennis & Co. 

AX              H. White & Co. 

AXA           H. White & Co. - Yarmouth

AY              R. Lambert

AZ              R. & J. Irving


B                  T. Brittan Ltd

BAB            AEI Telecommunications, Bristol

B2P             Inventec Electronics - Malaysia

BB               Brush Electrical Engineering Co.

BBK            Bakelite Ltd - Birmingham

BBL             Britannia Batteries Ltd.

BC               L. Herve Ltd.

BCC            Bristol Concrete Co. Ltd.

BCL             Bratt Colbran Ltd.

BD               W. T. Henley's Telegraph Works Co. Ltd.

BDA           unknown

BDB            W. T. Henley's Telegraph Works Co. Ltd - London (became AEI)

BE               Callenders Cable & Construction Ltd  (later BEB)

BEB             Callenders Cable & Construction Ltd - London E16 (previously BE)

BEL             The British Electric Lamps Ltd.

BET             The British Electric Transformer Co. Ltd.

BF               E. Spencer & Co. Ltd.

BG               Johnson & Phillips Ltd.

BH               Newton Chambers & Co.

BJ                Harcourts Ltd. - Birmingham

BJB             Bayliss, Jones & Bayliss Ltd.

BK               Magneta Time Co. Ltd (late Silent Electric Clock Ltd.)

BL               A. Bocchi

BLD            Birkby's Ltd - Liversedge, Yorks.

BM              H. Wallis

BN               Karabon Co. (see EJ)

BNSF          British NSF Co. Ltd.

BO               Standard Woodwork Co.

BQ               Stockall Marples & Co.

BS               Everett, Edgcumbe & Co. 

BSD            Mullard Radio Valve Co. - Mitcham, Surrey

BT               Prescot Clock & Mechanical Co.

BTR            Blick Time Recorders Ltd.

BU               C.H. Glover & Co.

BUL            Bullers Ltd. - Stoke on Trent

BV               Brown & Co.

BW             Cossor Ltd.

BX               Williamson Clock Co. Ltd.

BY               G. Welch & Sons


C                  General Electric Co. - Coventry, originally Peel Conner Ltd.  (later GEC)

C                  Found near a screw terminal - means Carbon and is the positive connection of a primary battery

CA              Blunden

CB               Chubb & Sons Lock & Safe Co. Ltd.

CCA            Carron Co (previously CC)

CCB            Creed & Co. Ltd - Brighton, Surrey

CCD            Creed & Co. Ltd - Croydon, Surrey

CCL           Cathodian Crystals Ltd - Needs confirmation may be incorrect or an in house code.

CD               Malcolm & Co.

CE                Boulton & Paul Ltd.

CF               H.W. Sullivan

CG               Grimshaw, Baxter & Elliott

CH               Alfred Graham & Co.

CJ                 Ingram Bros.

CK               H. White & Co. Ltd. (Watchmakers) - London EC1.

CL               Prison Commissioners of Scotland

CLS             Concrete Ltd.

CLV             Colvern Ltd.

CM              Mitchell

CN               Park Royal Engineering Co. Ltd, successors to Spagnoletti (see AD)

CO               D.H. Bonnella & Son Ltd.

CP               Weston Electrical Instrument Co. Ltd.

CPL             Crompton Parkinson Ltd.

CR               Crystalate Co. Ltd. 

CS               E.F. Gurnett

CSB             E.S. Gurnett

CT               Record Elec. Co.

CTP             Creed & Co. Ltd - Pontypridd, Glamorgan

CU               G.L. Beasley

CV               T.H. Brooker & Co. Ltd.

CW             Comyn Ching & Co. Ltd.

CWL           Pye Telecommunications - Cambridge. CW actually comes from Cambridge Works originally in Haig Road, Cambridge 

CWP           The Caxton Wood Turnery Co.

CX               E. Brook Ltd.

CY               Marconi Wireless Telegraph Co. Ltd.

CYA            Marconi Co. Ltd - Chelmsford, Essex

CZ               A.P. Buchanan


D                 India-Rubber and Gutta-Percha Telegraph Works Ltd, Silvertown

DA              W. Cowill & Sons

DAE            A.P. Besson Ltd - Hove, Sussex

DAW          Duct & Access Covers PLC - Wales

DB               J. Gell

DBA           John Gell Ltd

DBK            Bakelite Ltd - Durham

DC               The Synchronome Co.

DCA           Synchronome Co. Ltd - Wembley, Middx.

DD              William, Duncan, Tucker & Sons Ltd.

DE               Muirhead & Co.

DEA            Muirhead & Co. - Beckenham, Kent

DEK            Dover Engineering Co. - Dover, Kent

DF               British Telegraph Instrument Co.

DFM           Denis Ferranti Meters Ltd - Bangor, N. Wales

DG               T.O. Blake

DH              Willing & Co. 

DJ                The Telegraph Construction & Maintenance Co. Ltd.

DJA            Telegraph Construction & Maintenance Co. - London SE10 (see S and SEG)

DK              Buck & Hickman

DL               Drury Bros.

DM             Vaughtons Ltd.

DMR           Dynamo & Motor Repairs Ltd.

DN              H.J. Dawes

DNT            E. Dent & Co.

DO              Grant, Cameron & Curle

DP               Cheshire, Pooley & Co.

DR               Berry Skinner

DS               S.G. Jones

DT               J. Gerrard & Sons

DU              Cutlans

DV               Creed & Co.

DW             Repetition Woodwork Co.

DY               Staples & Co.

DZ               Relay Automatic Telephone Co.

DZA           Relay Automatic Telephone Co.


E                  Ericsson Telephones Ltd (British Ericsson)  - later Plessey, then GPT and then Siemens

EA               N. Berry & Sons

EB               Francis & Sons

EB               Found near screw terminals - means Extension Bell

EBL             Edison Bell Ltd.

EC               C. Lange

ECS             English Clock Systems

ED               The Waltham Cross Joinery Co. Ltd.

EE                Isenthal & Co.

EEC             Elliott Ltd - West Midlands

EET             Plessey - Beeston, Notts. (formerly Ericsson, see E)

EEX             Plessey - Sunderland (formerly Ericsson)

EF                Albion Iron & Wire Work Co. Ltd.

EFW            F.W. Elliott Ltd.

EG               S.E. Norris & Co.

EH               Cambridge Instrument Co. Ltd.

EHA            Cambridge Instrument Co. - London SW1

EJ                C.A. Apperley (Karabon)

EK               Clacton Joinery & Engineering Co.  Actually part of E. K. Cole

EL                Davis & Timmins

EM              The BKB Electric Motors Ltd.

EMI             EMI (Valve Division) - Ruislip, Middx.

EN               The British Time Recorder Co. Ltd.

ENA            British Time Recorder Ltd - London EC1 (previously EN)

EP                Potter & Co.

EQ               Anode Ltd.

ER               Bonnella Bros. 

ERM           Epoch Radio Manfg. Co. Ltd.

ES                Wm. Sanders & Co.

ESC             Enfield Stone Co. Ltd.

ET               Baxendale & Co. Ltd.

EU               Burnham & Co.

EV               G.W. Evans & Co.

EW              Baxter & Caunter

EX               C.A. Carter & Co.

EY               Buckleys (London) Ltd.

EZ               Zenith Manfg. Co. Ltd.


F                  GEC Ltd.

FAC            Fuller Accumulator Co. (1926) Ltd.

FB               GPO Factory, Birmingham

FBR             GPO Factory, Fordrough Lane, Birmingham (repaired apparatus, special cases only)

FC               Alex. Bruce & Co.

FD               Messrs. Hailwood & Ackroyd Ltd.

FE                Dubilier Condenser Co. (1921) Ltd.

FEL             Fidelity Ltd (see FID)

FEN             unknown

FF                Eclat Electric Lamp Manufactory

FG               Burt, Boulton & Haywood Ltd.

FGB             Sontranic Ltd - Edgware, Middx.

FH               GPO Factory - Holloway

FHA            GPO Factory - Holloway, London (Assembly)

FHB            GPO Factory - Holloway, London (Construction)

FHR            GPO Factory - Holloway, London (repaired apparatus, special cases only)

FID              Fidelity Radio Ltd (see FH)

FJ                The D.P. Battery Co. Ltd.

FJM            F.J. Moore Ltd.

FK               The Alton Battery Co. Ltd.

FL                The Accumulators of Woking

FM              Foster's Machine Tool & Engine Co.

FMC           Calne Electronics - Calne

FNB            GPO Factory - Edinburgh (Construction) (the N stood probably for ‘North Britain’)

FNR            GPO Factory - Edinburgh (Refurbish)

FR               Ferranti Ltd.

FRA            Ferranti Ltd - Hollinwood

FRG             unknown

FS                The Foster Engineering Co. Ltd.

FT               Messrs. F. Tray & Co. Ltd.

FW              GPO Factory - Wales (Cwmcarn)

FWG           STC Consumer Electronics - Cwmcarn (formerly BT factory)

FWR           GPO Factory - Cwmcarn, Wales (Refurbish)


G                  General Electric Co (GEC) - see C

GAB            Greenwood and Butler - Leeds

GB               Jas. Gibb & Co. Ltd.

GC               East & Son Ltd.

GE               G. Bruce

GEC             GEC Telephones - Coventry

GEG             Osram Lamp and Lighting Co. Ltd - Gateshead, Co. Durham

GEH            GEC - Middlesbrough

GEL             GEC-AEI Telecommunications - Accrington, Lancs.

GEM           Garrard Ltd.

GEN            GEC-AEI Telecommunications - Newton Aycliffe, County Durham

GEP             GEC Telecommunications Ltd - Treforest, Pontypridd

GF               Girlings Ferro Concrete Ltd.

GJ                Gillett & Johnston

GKT            GKN PLC - Telford, Shropshire

GM              G. Mugford

GNA           Pye, Aidrie (TMC from 1970) - see TMA

GNT            The Great Northern Telegraph Co. Ltd. of Denmark

GS               Gillson Syndicate

GTE             Ferranti joint venture with GTE (USA)

GZ               Doulton & Co.


H                 Automatic Telephone & Electric Co (ATE) (formerly ATM, H stands for Helsby)

HA              Hall Telephone Accessories Ltd. (later HAS)

HAA           Automatic Telephone & Electrical Co. - Liverpool (later Plessey)

HAS            Hall Telephone Accessories Ltd (formerly HA)

HB               Houghton  Butcher Manfg. Co. Ltd.

HC               British Insulated Cables Ltd.

HCA           BICC Cables - Warrington

HCC            BICC - Liverpool (ex Helsby Cables)

HCL            BICC - Leigh (ex Helsby Cables)

HCP            BICC - Prescot (ex Helsby Cables)

HD              C.A & A.W. Hayward

HDL            Hudson's Electrical Devices Ltd - London SW2

HE               H. Sloog (makers of Hennite)

HEA            H.E. Ashdown (Birmingham) Ltd.

HF               Eames Bros.

HG               Hart Accumulator Co. Ltd.

HH              J.E. Hough Ltd.

HJ                C. Hodges & Co. Ltd. (business purchased by J.L. Gottlieb & Co. Ltd.)

HK              Hillcrete Ltd.

HL               Holland & Sons Ltd.

HM             Chamberlain & Hookham Ltd.

HN              J. Hannan

HND           Highton & Sons - Dalston, London, E8

HR               Henry Brown & Sons

HS               Howells & Co.

HT               A.W. Hart

HVA           Plessey Hivac Division - Ruislip, Middx (ex Hivac Ltd)

HY               G.A. Harvey & Co. Ltd.


I                   (originally) International Electric Ltd.

I                   (later) Ibex, London (later IBX)

IA                British Die Casting & Engineering Co. Ltd.

IB                G.H. Bartlett

IBX             Ibex Telephones - Harrow, London (formerly I)

IM               Imperial Typewriter Co. Ltd.

IMP             Imperial Typewriter Co.

IT                International Time Recorder Ltd


JA               J.A. Crabtree & Co. Ltd.

JB                B.W. Johnson

JC                J. Chesterman & Co. Ltd.

JEK             unknown

JGS              Switchgear Co.

JK                Brooker and Jackson Ltd.

JKA            Brooker and Jackson Ltd. - London N1

JM               J. McKenzie & Co.

JN                John Norman Ltd.

JR                Joseph Reynolds

JS                J. & E. Bates

JX                Julius Sax & Co. Ltd.

JXA            Julius Sax & Co. Ltd.


K                 Kelvin, Bottomley & Baird Ltd.

KA              Calders Ltd.

KB               K. E. Beswick - Frome, Somerset

KC               E.A. Combs

KCP            Kent Concrete Products

KD              J. Cadman & Co. Ltd.

KE               Chloride Electrical Storage Co. Ltd.

KEC            E. K. Cole Ltd - Rochford, Essex (later EKCO Avionics)

KJ                J. Crombie & Son

KKA           E. K. Cole Ltd - Southend, Essex

KL               The Crypto Electrical Co. Ltd.

KM             The Camelinat Co. 

KNE            K & N Electronics Co. Ltd - Maidenhead, Berks.

KQ              Craig Lelo Quarry Co. Ltd.

KR               Cryselco Ltd.

KRN            Krone - Cheltenham

KS               Carver & Son

KT               The Croft Granite, Brick & Concrete Co. Ltd.

KU              The Concrete Unit Co. Ltd.

KZ               L. Keizer & Co. Ltd.


L                  Elliott Brothers Ltd

LDA            Cossor Communications Co. Ltd - Stanmore, Middx.

LE                Litholite Insulators Ltd.

LEA            Litholite Mouldings Ltd - Leicester (ex-Watford)

LEB             Elliott Bros. (London) Ltd - London SE13 (previously L)

LER             Lero Engineering Company - Coventry

LF                Lion Foundry Co. Ltd.  - Kirkintilloch, Glasgow (later LFA)

LFA            Lion Foundry Co. Ltd.  - Kirkintilloch, Glasgow (previously LF)

LK               W. & T. Lock

LN               Lissen Ltd.

LP                Lindsay, Parkinson & Co. Ltd.

LR               Thomas De La Rue

LS                Lang & Squire Ltd.

LUS             Lustraphone Ltd.

LWA          Lightwood & Son - Birmingham


M                                     (originally) P.O. Factory, St Johns Road, Dublin (derived from the Irish word for factory ‘Monarca’)

M                (later) W. Maxwell & Co. Ltd.

MA             Males & Andrews

MCA          P. McAinch Ltd.

MD             B.D. & Co. (Edward A. Boynton)

ME              F.W. Male & Son Ltd.

MF              Walter Macfarlane & Co. - Glasgow (later MFA)

MFA           Walter Macfarlane & Co. - Glasgow (previously MF)

MH             A.G. Matthews

MK             Marconi Scientific Instrument Co.

ML              C.A. Middleton Ltd.

MM            The Condenser & Electric Co. (originally)

MM            Murphy Radio Ltd - Welwyn Garden City, Herts. (later)

MN             Metropolitan Vickers Electrical Co. Ltd.

MOV           M.O. Valve Co. Ltd - London W6

MP              Moulded Products Ltd.

MRL           McMichael Ltd.

MS              Mead Ltd (originally)

MS              McDowell Steven & Co. - Falkirk (afterwards, later MSL)

MT              Moore & Wright Ltd.

MTW         Modern Telephones Ltd - Wimbledon, London SW19

MTJO         Mullard Ltd - London WC1

MTC           Millars' Timber & Trading Co. Ltd.

MU             Murray (c/o Reid Bros., see R)

MV              Mullard Radio Valve Co. Ltd.

MW            Micklewright Ltd.

MWB         Marconi Wireless Telegraph Co. - Basildon, Essex

MXB           Motorola - Basingstoke, Hants.


N                 Nalder Bros.

NB               Newton Bros (Derby) Ltd.

NE               North of England School Furnishing Co.

NJ                British Nigerian Timber Co.

NS               Neill, Small & Sons

NTS            The Norton Boys' Home

NW             Norwest Construction Co. Ltd.


O                 Gent & Co. (later OAA)

OAA           Gent & Co. - Leicester (previously O)

OD              D.M. Davies

OE               unknown

OM             Oldham & Son


P                  R.W. Paul Ltd

PA               Parkes, Samuel & Co. Ltd.

PBI              Plessey – Ballynahinch, N. Ireland

PC               H.M. Prison Commission

PCB             Plessey - Whiteside Works, Bathgate, West Lothian (see PLF)

PE                The Power Equipment Co. Ltd.

PEH             Pye - Hastings

PER             Plessey Electrical Equipment Division - Romford, Essex

PG               The Pitter Gauge & Precision Tool Co.

PGH            Pirelli - Eastleigh, Hants.

PGL              Pirelli - Southampton

PH               W.G. Pye & Co.  Not actually part of PYE Group after the sale of PYE Radio to C. O. Stanley, it was a separate company producing Scientific Instruments

PK               Chas. Peacock & Co. Ltd.

PL                The Plessey Co. Ltd. - Ilford, Essex (later PLA)

PLA            Plessey - Ilford, Essex ( also TLA, previously PL)

PLF             Plessey - Whiteside Works, Bathgate, West Lothian

PLS             Plessey - Kemberry Rd, Swindon, Wilts.

PLJ              Plessey - Upminster, Essex

PLV             Plessey - Havant, Hants.

PLW           Plessey - Cheney Manor, Swindon, Wilts.

PLX             Plessey - Newport, Gwent

PLY             Plessey - Titchfield

PM              Reliance Telephone Co. Ltd - Birmingham

PMC           A.T.E. (Wigan) Ltd - Pioneer Works, Wigan, Lancs. (see PML)

PML            A.T.E. Ltd - Chorley, Lancs.

PN               Radio, Phonopore and Electricals Ltd.

PR               The Premier Accumulator Co. (1921) Ltd.

PS                The Parkside Engineering Co. Ltd.

PSD             Plessey - Dublin, Ireland

PSL             Poulton Selfe & Lee Ltd - Wickford, Essex

PTB             Pye Thermal Bonders

PTE             Pye Telecommunications Ltd - Ekco Works, Southend, Essex (see KKA)

PTL             Pye Telecommunications Ltd - PTL  was the designation of PYE, Ditton works, Newmarket Road, Cambridge. Later it was St Andrews  Road new Factory which replaced Ditton Works and Quy Mill research centre.

PW              Palmer & Waumsley

PX               Phoenix Telephones & Electrical Works Ltd. - London NW9 (later PXA)

PXA            Phoenix Telephones & Electrical Ltd. - London NW9 (formerly PX)

PYE             Pye Telecommunications. Ltd. - Cambridge (see CWL)

PYI              Pye Radio Ltd. - Cambridge

PYL             Pye Radio Ltd. - Leicester

PYT             Plessey - Taplow, Maidenhead, Berks.

PZ               Pritchett & Gold and E.P.S. Co. Ltd.


R                  Reid Bros.

RA              Radio Instruments Ltd.

RAA           Landis & Gyr (formerly Aeronautical & General)

RAW          Roberts & Armstrong (Engineers) Ltd - Wembley, Middx.

RBA            Reid Brothers (Same as W Reid & Co.?)

RC               Ross, Courtney & Co. 

RD               W. & M. Richmond & Co.

RE               Reliable Engineering Co.

RF               Royal Gun & Carriage Factories

RH               Ruston & Hornsby Ltd.

RIA             Rathdown Industries Ltd - Ascot, Berks.

RLA            Ryford Ltd - Aldridge, Staffs.

RLE             Ripaults Ltd - Enfield, Middx.

RML           Rotheroe & Mitchell Ltd - Greenford, Middx.

RNA           Radio, Phonopore & Electricals Ltd (Sterling took over)

RR               R. Robertson

RS               Radio Supplies

RT               Robert Edwards

RTL             Racal Transcom Ltd - Salisbury, Wilts.

RTN            Reliance Telephone Co. Ltd - Birmingham

RV               Revo Electric Co. Ltd.


S                  Siemens Bros. & Co. Ltd. - Woolwich, London SE15 (later SEG)

SA               The Saunders Electrical Co.

SAV            W. Bryan Savage

SB               S.G. Brown Ltd.

SBD            Stonebridge Electrical Co. Ltd.

SBM           Salford Electrical Instruments - Manchester

SC               L.C. Smith & Corona Typewriters Ltd.

SCP             Surrey Concrete Products Ltd.

SD               S. Davall & Sons

SE                Small Electric Motors Ltd.

SEA            Siemens-Edison Swan - London N17 (became part of AEI)

SEC             Salford Electrical Instruments - Heywood, Lancs. (part of GEC)

SEG             AEI Ltd - Woolwich, London SE18 (ex Siemens, see S)

SER             AEI Ltd - West Hartlepool, Co. Durham (ex Siemens)

SEW           Siemens Edison Swan - Woolwich, London SE15 (see SEA)

SF                Scofield & Flexton

SFC             Standard Fuse Co.

SG               G. Salter & Co. Ltd.

SID              Salmon Industries Ltd - Northern Ireland

SL                S.G. Leach & Co. Ltd.

SLW           Speke Telephones Ltd - Wilmslow, Middx. (see SPK)

SM              Stuart & Moore (taken over by G. Longfield-Beasley)

SN               Solidite & Synthetic Mouldings Ltd.

SP                Small Power Dynamo & Motor Co. Ltd.

SPK             Plessey - Speke, Liverpool (ex Speke Telephones Ltd., see SLW)

SR               Estler Bros.

SS                Ebonestos Insulators Ltd.

SSA            Ebonestos Industries Ltd - London SE15 (previously SS)

SSG             Splintex Safety Glass Co - London W7

SSL             Siemens-Schuckert (Gt. Britain) Ltd.

SSS             S. Smith & Sons (Motor Accessories) Ltd.

SSS             Smith's Industrial Instruments Ltd - London NW1

ST               Stuart Turner Ltd.

STC             STC - New Southgate, London N11

STD            STC - Footscray

STE             STC (Valve Division) - Paignton, Devon

STJ              STC- Harlow

STK            STC – Boreham Wood

STM           STC - Monkstown, N. Ireland

STO            STC – East Kilbride

STU            STC – Enfield

STW           STC - Taunton

SU               The Educational Supply Association Ltd.

SUE             Submarine Cables Ltd - Erith, Kent

SUG            Submarine Cables Ltd - Greenwich, London SE3 (see DJA and S)

SUR            Siemens Halske - Germany

SV               D.G. Somerville & Co. Ltd.

SY               H.C. Slingsby


T                  Tyer & Co.

TA              Thermega Ltd.

TB               Turner Bros. Ltd.

TBE             Telerelays Sales Ltd -Braintree, Essex

TCC            Telegraph Condenser Co.

TCD            Telephone Cables Ltd - Dagenham, Essex

TCE             STC - Enniskillen, N. Ireland

TCH            STC - Larne, N. Ireland

TCJ             STC – Jenny Mount (Belfast), N. Ireland

TCL             Trent Concrete Ltd.

TCON         Team Concepts International Ltd (Hong Kong)

TCT            STC – Treforest

TCW           STC – Rhyl

TCS             STC – Chase Side

TD               H.J. Townsend

TE               Telephone Manufacturing Company (formed 1915, later TEA)

TEA            TMC - Dulwich, London SE21

TES             TMC - St Mary Cray, Kent (from 1939)

TEW           TMC - Winsford, Cheshire

TF               Timber Fireproofing Co. Ltd.

TG               Tungstone Accumulator Co. Ltd.

TGR            Thorn Ericsson - Rochester, Kent

TGW           Thorn Ericsson - Scunthorpe

TH               The British Thomson-Houston Co. 

TK               The Bradford Patent Truck & Trolley Co.

TL               Eastern Telegraph Co. Ltd.

TLA            Plessey - Ilford, Essex (also PLA)

TM              Telephone & Microphone Co.

TMA          TMC - Airdrie, Lanarkshire (see GNA)

TMC           Telephone & Microphone Co.

TMK           TMC - King's Lynn, Norfolk

TM              TMC - Malmesbury, Wilts.

TN               J.W. Thomson

TP               Thornton Pickard Manfg. Co. 

TPC             TMC Transmission Division - St. Mary Cray, Kent

TR               Ernest Turner Electrical Instruments Ltd. - High Wycombe (later TPA)

TRA            Ernest Turner Electrical Instruments Ltd. - High Wycombe (formerly TR)

TS               The Thames Manfg. Co. Ltd.

TSD            Telephone Supplies Ltd - Aycliff, Co. Durham

TT               Taylor, Tunnicliffe & Co. Ltd.

TTC            Taylor Tunnicliffe & Co. Ltd. - Lastwood, Hanley, Staffs.

TTH            TMC - Canterbury, Kent

TTL             TMC - Livingstone, Bathgate, West Lothian (from 1969)

TU               The Tudor Accumulator Co. Ltd.

TW             Tate & Wilkinson

TY               H. Tinsley & Co.

TYA            H. Tinsley & Co.


U                 Walters & Co.

UAA           Walters Electrical Manufacturing Co. Ltd - London (previously U)

UG               United Woodworking Co. Ltd.

UME           Multitone Ltd.

UW             Underwood Portable Typewriters Ltd.


V                  T. Watson

VA              The Varley Magnet Co.

VD               The Ever Ready Co. (Gt. Britain) Ltd.

VG               Evershed & Vignoles Ltd. - London W4. Later VGA

VGA            Evershed & Vignoles Ltd. - London W4 (previously VG)

VK               Vickers Ltd.

VLC             Varta Ltd - Crewkerne, Somerset

VN               Vanesta Ltd.

VS               Evans Bros. Ltd.

VTS             Venner Time Switches - New Malden, Surrey

VV               C.A. Vandervell & Co. Ltd.

VW             Visible Writing Machine Co. Ltd.


W                STC - North Woolwich, London (Western Electric pre-1925, see WAA)

WAA         STC - North Woolwich, London E

WAB          STC - Newport, S. Wales

WAE          STC - Basildon, Essex

WAF          STC - Southampton

WAS          STC - Southampton

WB             Westinghouse Brake & Saxby Signal Co. Ltd.

WC             Walsall Conduits Ltd.

WEA          Weatherlite Ltd.

WEE           W.E. Eaton

WER           Whiteley Electrical Radio - Mansfield, Notts.

WF              W.H. Foster & Sons Ltd.

WG             Ward & Goldstone Ltd.

WH             Wm. White & Co.

WI               Webb & Wells - Ilford, Essex

WJ              Walter Jones & Co. Ltd.

WK             L. Weekes Ltd.

WS              M.W. Woods

WW            The Wilson Wolf Engineering Co. Ltd.


X                 Wilcox

Y                  W. Wilson

YA              British Army line stores prefix (not a BPO manufacturer code)


Z                  Negretti & Zambra Ltd.

Z                Found near a screw terminal - means Zinc and is the negative pole of a primary battery

ZA              British Army wireless stores  (not a BPO manufacturer code)

ZEA            Zenith Watch Co. Ltd (GB) (Previously ZE)

ZE               Zenith Watch. Co. Ltd. *Gt. Britain)



Moulding marks

BLD or BLtd     Birkby's of Liversedge (W. Yorks.), the plastics moulding division of Plessey.

C                GEC Ltd (Telephone Works, Coventry)

G                GEC Ltd

LR              Thomas De La Rue Ltd,

MPL           Moulded Products Ltd

S                 Siemens Brothers Ltd.


Title numbers
All BPO telephone sets (also equipment large and small) carried a ‘title number’, in which table telephones, portable telephones and piece parts such as handsets carried even numbers whilst wall telephones had odd numbers.  Special and experimental telephones had numbers prefixed SA (Subscribers’ Apparatus), whilst designs inherited from the former National Telephone Company were prefixed NT.

As well as the title number, telephones normally carried a mark number and the date of manufacture. The original design is known as Mark 1, the first modification as Mark 2 and the second as Mark 3 (and so on). Earlier on original designs and modifications were identified by three digits, starting with 234, for the original design, then 235 for the first modification, 236 for the second modification and so on. 

Examples:  Telephone 162 C34/1 indicates title number 162, made by GEC in 1934 to the Mark 1 design.  Under the older scheme of marking this would have been shown as

 C34    No. 162

Moulded items carried a letters and number code in which the upper two letters indicated the item manufacturer, the lower two letters the moulding subcontractor and the numeral the type of moulding material.

Non-BPO codes

British Codes
Note that type numbers of telephones beginning AP or Z are not BPO codes. AP stands for Admiralty Pattern, denoting a Royal Navy design, and YA and ZA are British Army prefixes. A pattern number starting 10A (or 10 followed by another letter) is Ministry of Defence. Type numbers beginning H are generally ATE products (the company originated at the place of Helsby), N denotes British Ericsson products, S are Siemens Brothers or AEI numbers, TEL is normally GEC, whilst a number beginning SA on BPO instruments denotes Subscribers’  Apparatus, generally a pre-release prototype or an item made specially for a particular customer.

Australian PMG manufacturer codes
Manufacturer codes were allocated by the Postmaster General are generally as for the BPO, with the addition of B.I. and B.I.H., which both indicate British Insulated Cables Ltd, located at Helsby. The ATM company was a spin-off of B.I. which itself merged with Callander’s Cables Ltd and became BICC.

New Zealand
Some telephones made for the New Zealand Post Office carried the initials HCUNZ, standing for H.C. Urlwin of Christchurch, New Zealand.

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Last revised: January 09, 2011