IOM

Isle of Man

CHA

Channel Isles

Wales (WLS)

AGY	Anglesey	BRE	Breconshire	CAE	Caernarvonshire
CGN	Cardiganshire	CMN	Carmarthenshire	DEN	Denbighshire
FLN	Flintshire	GLA	Glamorganshire	MER	Merionethshire
MGY	Montgomeryshire	PEM	Pembrokeshire	RAD	Radnorshire

Ireland (IRL)

CAR	Carlow	CAV	Cavan	CLA	Clare
CNT	Connaught	COR	Cork	DON	Donegal
DUB	Dublin	GAL	Galway	KER	Kerry
KGS	King's (Offaly)	KID	Kildare	KIK	Kilkenny
LAS	Leix (Queen's)	LET	Leitrim	LIM	Limerick
LNR	Leinster	LOG	Longford	LOU	Louth
MAY	Mayo	MEA	Meath	MOG	Monaghan
MUN	Munster	OFF	Offaly (King's)	QNS	Queen's (Leix)
ROS	Rosscommon	SLI	Sligo	TIP	Tipperary
WAT	Waterford	WEM	Westmesth	WEX	Wexford
WIC	Wicklow

Northern Ireland (NIR)

ANT	Antrim	ARM	Armagh	DOW	Down
FER	Fermanagh	LDY	Londonderry	TYR	Tyrone

Scotland (SCT)

ABD	Aberdeenshire	ANG	Angus	ARL	Argyllshire
AYR	Ayrshire	BAN	Banffshire	BEW	Berwickshire
BUT	Buteshire	CAI	Caithness	CLK	Clackmannanshire
CRM	Cromartyshire	DFS	Dumfriesshire	DNB	Dunbartonshire
ELG	Elginshire	ELN	East Lothian	FIF	Fifeshire
FOF	Forfarshire	INV	Inverness-shire	KCD	Kincardineshire
KRS	Kincross-shire	KKD	Kirkcudbrightshire	LKS	Lanarkshire
LNL	Linlithgowshire	MOR	Morayshire	NAI	Nairnshire
ORK	Orkney	PEE	Peebleshire	PER	Perthshire
RFW	Renfrewshire	ROC	Ross and Cromarty	ROX	Roxburghshire
RSS	Ross-shire	SEL	Selkirkshire	STI	Stirlingshire
SUT	Sutherland	TDD	Tweeddale	WIG	Wigtownshire
WIS	Western Isles	WLN	West Lothian	ZET	Shetland

The above are taken from BS 6879 which in turn are based upon the "Chapman County Codes"