Chapman code

The Chapman codes are a set of three-letter codes adopted to identify counties and other areas of the British Isles. They were compiled by Dr Colin Chapman in the 1970s in connection with his work on computerised records, in particular for the Schools Council's national project to introduce the use of computers in British schools in the early 1970, and the "Chapman County Codes" as they became known swiftly spread. Today they are most widely used in genealogy.

Development

Chapman's achievement was to produce a single set of codes in a consistent system, capable of use universally. It was not the first set of county abbreviations by any means; the English Place Name Society produced a series of abbreviations in 1923 for counties in England but a mixed system of one-letter, two-letter and three-letter abbreviations. The Society of Genealogists published a list of abbreviations for the whole of the British Isles in 1973.

In the 1970s Dr Chapman studied the systems published by the English Place Name Society and the Society of Genealogists and determined that a consistent system required a set of three-letter codes. Some of these were the same three-letter code used by the Society of Genealogists but two-letter and one-letter codes were expanded.

Only two counties were missed off the system: Cromartyshire and Ross-shire. (A code ROC was adopted for the administrative area "Ross and Cromarty".)

Chapman's system covered not only the counties but certain other areas, such as the Isle of Wight (IOW), the City of London (LON) and each of the three Ridings of Yorkshire. He also adopted codes for administrative counties and for the local government areas invented by the 1972 Local Government Act.

The Chapman codes are now incorporated in national and international standards for abbreviations: BS 6879 and the ISO 3166-2:GB, to identify historic counties and administrative divisions past and present in the United Kingdom, the Republic of Ireland, the Isle of Man and the Channel Islands.

The Historic Counties Standard codes

The Historic Counties Trust in developing the Historic Counties Standard adopted a separate system of codes similar to the Chapman codes. The Chapman codes were rejected since they are used, in accordance with the published British Standard, to stand in for names which might have several different applications, which is to say that the code "CAM" stands for "Cambridgeshire" but may be used for the county of that name or for the administrative area which uses the same name but which has a very different extent. Therefore, a new set of codes was required to represent the historic counties only, and which codes were required not to overlap with any Chapman code.

The Historic Counties Trust codes cover all the counties of the United Kingdom. The system was developed by Dr Peter Boyce.

The Codes

The table below gives the Chapman code for each county, together with the Historic Counties Standard code and Historic Counties Standard number.

Counties of the United Kingdom

Chapman	HCS	HCS No.	County
ABD	ABN	01	Aberdeenshire
AGY	AGL	02	Anglesey
ANS	ANG	03	Angus
ANT	ANM	04	Antrim
ARL	ARG	05	Argyllshire
ARM	ARH	06	Armagh
AYR	AYS	07	Ayrshire
BAN	BNF	08	Banffshire
BDF	BED	09	Bedfordshire
BRK	BER	10	Berkshire
BEW	BRW	11	Berwickshire
BRE	BRN	12	Brecknockshire
BKM	BUC	13	Buckinghamshire
BUT	BTE	14	Buteshire
CAE	CRN	15	Caernarfonshire
CAI	CTN	16	Caithness
CAM	CMB	17	Cambridgeshire
CGN	CRD	18	Cardiganshire
CMN	CRM	19	Carmarthenshire
CHS	CHE	20	Cheshire
CLK	CLM	21	Clackmannanshire
CON	CNW	22	Cornwall
-	CRT	23	Cromartyshire
CUL	CUM	24	Cumberland
DEN	DBH	25	Denbighshire
DBY	DRB	26	Derbyshire
DEV	DVN	27	Devon
DOR	DRS	28	Dorset
DOW	DWN	29	Down
DFS	DMF	30	Dumfriesshire
DNB	DUN	31	Dunbartonshire
DUR	DRH	32	Durham
ELN	ELT	33	East Lothian
ESS	ESE	34	Essex
FER	FRM	35	Fermanagh
FIF	FFE	36	Fife
FLN	FLT	37	Flintshire
GLA	GLM	38	Glamorgan
GLS	GLC	39	Gloucestershire
HAM	HMP	40	Hampshire
HEF	HRF	41	Herefordshire
HRT	HTF	42	Hertfordshire
HUN	HNT	43	Huntingdonshire
INV	INS	44	Inverness-shire
KEN	KNT	45	Kent
KCD	KNC	46	Kincardineshire
KRS	KNR	47	Kinross-shire
KKD	KCB	48	Kirkcudbrightshire
LKS	LNK	49	Lanarkshire
LAN	LCS	50	Lancashire
LEI	LCR	51	Leicestershire
LIN	LNC	52	Lincolnshire
LDY	LDR	53	Londonderry
MER	MRN	54	Merionethshire
MDX	MSX	55	Middlesex
MLN	MLT	56	Midlothian
MON	MNM	57	Monmouthshire
MGY	MTG	58	Montgomeryshire
MOR	MOY	59	Morayshire
NAI	NRN	60	Nairnshire
NFK	NRF	61	Norfolk
NTH	NHP	62	Northamptonshire
NBL	NHB	63	Northumberland
NTT	NOT	64	Nottinghamshire
OKI	ORN	65	Orkney
OXF	OXD	66	Oxfordshire
PEE	PBS	67	Peeblesshire
PEM	PMB	68	Pembrokeshire
PER	PRT	69	Perthshire
RAD	RDN	70	Radnorshire
RFW	RNF	71	Renfrewshire
-	RSS	72	Ross-shire
ROX	RXB	73	Roxburghshire
RUT	RTL	74	Rutland
SEL	SKK	75	Selkirkshire
SHI	SHT	76	Shetland
SAL	SHP	77	Shropshire
SOM	SMS	78	Somerset
STS	STF	79	Staffordshire
STI	STL	80	Stirlingshire
SFK	SFF	81	Suffolk
SRY	SUR	82	Surrey
SSX	SUS	83	Sussex
SUT	SRL	84	Sutherland
TYR	TYN	85	Tyrone
WAR	WRW	86	Warwickshire
WLN	WLT	87	West Lothian
WES	WML	88	Westmorland
WIG	WGT	89	Wigtownshire
WIL	WTS	90	Wiltshire
WOR	WRC	91	Worcestershire
YKS	YRK	92	Yorkshire

Islands

Chapman	Island
ALD	Alderney
GSY	Guernsey
JSY	Jersey
SRK	Sark
IOM	Isle of Man

Counties of the Republic of Ireland

Chapman	County
CAR	Carlow
CAV	Cavan
CLA	Clare
COR	Cork
DON	Donegal
DUB	Dublin
GAL	Galway
KER	Kerry
KID	Kildare
KIK	Kilkenny
LET	Leitrim
LEX	Leix
LIM	Limerick
LOG	Longford
LOU	Louth
MAY	Mayo
MEA	Meath
MOG	Monaghan
OFF	Offaly
ROS	Roscommon
SLI	Sligo
TIP	Tipperary
WAT	Waterford
WEM	Westmeath
WEX	Wexford
WIC	Wicklow

References

• Colin Chapman on the Chapman County Codes (Lochin Publishing)