London had a lot of telephone exchanges and when direct dialling fully arrived in the capital, the exchanges were arranged alphabetically. Rather, each number on the dial had letters next to it. Exchanges would be numbered but used an easy-to-remember alphabetical equivalent. Each exchange would have three beginning letters to begin with, which is what the customer dialled.

Using an alphabetical system, the designers of the alphabetical system were limited in options.

Telephone dials had the numbers 1 through to 0 via 2,3,4,5,6,7,8 and 9.

Next to the 2 were the letters A, B and C.
Next to 3: D, E and F.
Next to 4: G, H and I.
Next to 5: J, K and L.
Next to 6: M and N.
Next to 7: P, R and S.
Next to 8: T, U and V.
Next to 9: W, X and Y.
Next to 0: O and Q.

No exchanges began with the number 1 - these were reserved numbers for GPO services - 100 was the operator; 123 was the speaking clock. And 1 couldn’t be used as no letters were next to it.

Similarly, no exchanges could begin with a 0 - these were reserved for the expected arrival of national direct dialling at a distant date in the future.

So that it could be found easily in an emergency in the dark (one hole back from the metal stopper beside the zero), the number 999 was reserved for police, fire and ambulance.

Each exchange code was three numbers long and hence three beginning letters long.

London telephone exchange designers were left with numbers stretching from 220 to 998, never using a 1 and rarely utilising a zero (since O was a rare letter and Q almost impossible to fit in)

Some exchanges were easy to ’alphabetise’ logically.

The first exchange numerically was 220. We’ll come back to this.

There couldn’t be a 221 since 1 had no letters next to it.

The second exchange alphabetically and numerically was ABBey (for Westminster). Westminster had an Abbey. Easy to remember. The customer dialled 222 for this exchange A-B-B. Why not WEStminster? 937, W-E-S? Because that was reserved for "WEStern" in Kensington.

223 could be used for exchange names beginning AAD, AAE, AAF, ABD, ABE, ABF, ACD, ACE, ACF, BAD, BAE, BAF, BBD, BBE, BBF, BCD, BCE, BCF, CAD, CAE, CAF, CBD, CBE, CBF, CCD, CCE or CCF.

Of these, ABE, ACE, BAD, BAF, CAD, CAF could have been matched up with words. But they weren’t so 223 was left as a spare.

224 was also spare.

225 was BALham. Nice. Tooting area served
226 was CANonbury. Makes sense.
227 was BARnet. Yep.
228 was BATtersea. Cooking with gas now.
229 was BAYswater. Easy to remember.

So what about 220 which we left to come to later?

Here are the 220 combinations: AAO, AAQ, ABO, ABQ, ACO, ACQ, BAO, BAQ, BBO, BBQ, BCO, BCQ, CAO, CAQ, CBO, CBQ, CCO or CCQ.

Pretty useless.

Acton deep in west London had an exchange. A-C-T would be 228. 228 was already BATtersea. What’s that I hear. There’s a road in Acton already called Acorn Gardens? Perfect. Acton would be A-C-O. 220. ACOrn.

This is just the 22 numbers. All over London exchange names were needed. Most were sensible:
BELgravia (235), FINchley, (346), SYDenham (793), BERmondsey (237), PERivale (737), BEXleyheath (239),

Some went a bit generic - CENtral (for the City of London), CHAncery (Holborn) or EASt (Poplar) - roughly in the “East End”

But finally we come to the wonderful and utterly whacky exchange names of London. Some with dubious justifications. Some just weird made-up nonsense.

AMBassador for Paddington - some embassies are there
AMHerst for Hackney because of the world famous Amhurst Road
AVEnue for the area around the Monument in the City of London. Throgmorton Avenue. Obvious.

The other strange ones were:

ARNold North Wembley
ATLas Isleworth
BLUebell Addiscombe and South Norwood
BRUnswick King’s Cross
BYRon South Harrow
BYWood Purley and Kenley several woods
CHErrywood Merton and South Wimbledon Cherry Wood (Shaldon Drive)
CLIssold Dalston Clissold Park
CLOcktower East Ham
CONcord South Harrow
COPpermill Walthamstow Coppermill Lane
CREscent Barkingside and Redbridge
CUNningham Maida Vale
DERwent Worcester Park
DICkens Highbury
DILigence Wembley
DOMinion Dagenham
DREadnought Earls Court
DRUMmond North Wembley
DRYden Kingsbury
DUKe Fulham
DUNcan Catford
EDWard Kingston
ELGar Harlesden Elgar Avenue (off Mitchellbrook Way), NW10
EMBerbrook Thames Ditton
EMPress West Kensington
ENTerprise Southgate
FAIrlands Sutton and Cheam
FIEld End Pinner and Eastcote
FITzroy Hornsey and Highgate
FLAxman Chelsea
FLOral Mortlake
FOUntain Streatham
FOX Lane Palmers Green
FRAnklin Wallington and Carshalton
FREmantle Earls Court
FRObisher Earls Court
GALleon Worcester Park
GEOrgian Ealing
GIBbon was Putney as everybody knew the Edward (Decline and Fall of the Roman Empre) Gibbon was born in Putney
GLAdstone Cricklewood and Dollis Hill
GRImsdyke Stanmore see note
GULliver Kentish Town
HOGarth Shepherds Bush
HOP Southwark historically several hop merchants
HOWard Ponders End
HUDson Hounslow and Heston
HUNter St Marylebone
IMPerial Chislehurst and Bickley Louis-Napoléon lived and died here
IVAnhoe Woodford and Buckhurst Hill
IVYdale Ewell
JUNiper St.Johns Wood
KEAts Enfield
KELvin Balham
KIPling Mottingham and Grove Park
LABurnum Winchmore Hill
LAGoon Surbiton Surbiton Lagoon
LAKeside Wimbledon Lake in Wimbledon Park
LANgham Bloomsbury Langham Place
LARkswood Highams Park Larks Wood
LATimer Stamford Hill
LIBerty Merton and South Wimbledon
LIVingstone Norwood Livingstone Road
MACaulay Nine Elms
MEAdway Golders Green
MELville Sutton and Belmont
MINcing Lane City of London (Monument) Mincing Lane
MONarch City of London
MOUntview Hornsey and Highgate
MULberry Wood Green
MUNicipal Croydon see note
NATional City of London (Moorgate)
NOBle West Kensington
NUFfield Hayes and Cranford
POLlards Norbury Pollards Hill
POPesgrove Twickenham road called Popes Grove named after Alexander Pope
PRImrose St.Johns Wood Primrose Hill
PROspect Mortlake
RAGlan Leytonstone
RAVensbourne Bromley river Ravensbourne
REDpost Brixton Red Post Hill
RELiance Kennington and Walworth (Vauxhall)
RENown Fulham
RIPpleway Barking Ripple Road
RODney Camberwell and Walworth Rodney Road
SCOtt Nine Elms
SILverthorn Chingford
SKYport London Airport Heathrow and Harlington -
SPArtan Dalston
SPEedwell Golders Green
SPRingpark West Wickham Spring Park
STOnegrove Edgware Stonegrove (Watling Street)
SULlivan Westminster
SUNnyhill Hendon
TABard Fleet Street Tabard Inn (building)
TATe Gallery Victoria Tate Gallery
TERminus Kings Cross railway termini
TIDeway Deptford Thames tideway
TOWnley Dulwich and Camberwell Townley Road
TRAfalgar Whitehall Trafalgar Square
TREvelyan Ilford
TROjan Wandsworth
TUDor Muswell Hill
UNDerhill Harrow under Harrow-on-the-Hill
UPLands Purley and Kenley high ground
VALentine Ilford Valentine Public House, 27 Perth Road
VANdyke Wandsworth
VIGilant Sutton and Belmont don’t know - see note
VIKing Northolt and Yeading Viking Primary School, Radcliffe Way
VIRginia Finchley
WARing Park Sidcup Waring Park
WAXlow Greenford Waxlow Crescent
WELbeck St Marylebone Welbeck Street
WIDmore Bromley Widmore Road
WORdsworth Kenton


Elgar Avenue, Stonebridge Park was built after the Elgar exchange got its name and that the exchange may in fact have had an influence on the name of the Avenue.