Chapman Codes (sorted by code)
| ABD | Aberdeenshire | Scotland |
| AGY | Anglesey | Wales |
| ALD | Alderney | Channel Islands |
| ANS | Angus | Scotland |
| ANT | Co. Antrim | Northern Ireland |
| ARL | Argyllshire | Scotland |
| ARM | Co. Armagh | Northern Ireland |
| AVN | Avon | England |
| AYR | Ayrshire | Scotland |
| BAN | Banffshire | Scotland |
| BDF | Bedfordshire | England |
| BEW | Berwickshire | Scotland |
| BKM | Buckinghamshire | England |
| BOR | Borders | Scotland |
| BRE | Breconshire | Wales |
| BRK | Berkshire | England |
| BUT | Bute | Scotland |
| CAE | Caernarvonshire | Wales |
| CAI | Caithness | Scotland |
| CAM | Cambridgeshire | England |
| CAR | Co. Carlow | Ireland |
| CAV | Co. Cavan | Ireland |
| CEN | Central | Scotland |
| CGN | Cardiganshire | Wales |
| CHI | Channel Islands | Channel Islands |
| CHS | Cheshire | England |
| CLA | Co. Clare | Ireland |
| CLK | Clackmannanshire | Scotland |
| CLV | Cleveland | England |
| CMA | Cumbria | England |
| CMN | Carmarthenshire | Wales |
| CON | Cornwall | England |
| COR | Co. Cork | Ireland |
| CUL | Cumberland | England |
| CWD | Clwyd | Wales |
| DBY | Derbyshire | England |
| DEN | Denbighshire | Wales |
| DEV | Devon | England |
| DFD | Dyfed | Wales |
| DFS | Dumfries-shire | Scotland |
| DGY | Dumfries and Galloway | Scotland |
| DNB | Dunbartonshire | Scotland |
| DON | Co. Donegal | Ireland |
| DOR | Dorset | England |
| DOW | Co. Down | Northern Ireland |
| DUB | Co. Dublin | Ireland |
| DUR | Co. Durham | England |
| ELN | East Lothian | Scotland |
| ENG | England | England |
| ERY | East Riding of Yorkshire | England |
| ESS | Essex | England |
| FER | Co. Fermanagh | Northern Ireland |
| FIF | Fife | Scotland |
| FLN | Flintshire | Wales |
| GAL | Co. Galway | Ireland |
| GLA | Glamorgan | Wales |
| GLS | Gloucestershire | England |
| GMP | Grampian | Scotland |
| GNT | Gwent | Wales |
| GSY | Guernsey | Channel Islands |
| GTM | Greater Manchester | England |
| GWN | Gwynedd | Wales |
| HAM | Hampshire | England |
| HEF | Herefordshire | England |
| HLD | Highland | Scotland |
| HRT | Hertfordshire | England |
| HUM | Humberside | England |
| HUN | Huntingdonshire | England |
| HWR | Hereford and Worcester | England |
| INV | Inverness-shire | Scotland |
| IOM | Isle of Man | Isle of Man |
| IOW | Isle of Wight | England |
| IRL | Ireland | Ireland |
| JSY | Jersey | Channel Islands |
| KCD | Kincardineshire | Scotland |
| KEN | Kent | England |
| KER | Co. Kerry | Ireland |
| KID | Co. Kildare | Ireland |
| KIK | Co. Kilkenny | Ireland |
| KKD | Kirkcudbrightshire | Scotland |
| KRS | Kinross-shire | Scotland |
| LAN | Lancashire | England |
| LDY | Co. Londonderry | Northern Ireland |
| LEI | Leicestershire | England |
| LET | Co. Leitrim | Ireland |
| LEX | Co. Laois | Ireland |
| LIM | Co. Limerick | Ireland |
| LIN | Lincolnshire | England |
| LKS | Lanarkshire | Scotland |
| LND | London | England |
| LOG | Co. Longford | Ireland |
| LOU | Co. Louth | Ireland |
| LTN | Lothian | Scotland |
| MAY | Co. Mayo | Ireland |
| MDX | Middlesex | England |
| MEA | Co. Meath | Ireland |
| MER | Merionethshire | Wales |
| MGM | Mid Glamorgan | Wales |
| MGY | Montgomeryshire | Wales |
| MLN | Midlothian | Scotland |
| MOG | Co. Monaghan | Ireland |
| MON | Monmouthshire | Wales |
| MOR | Morayshire | Scotland |
| MSY | Merseyside | England |
| NAI | Nairn | Scotland |
| NBL | Northumberland | England |
| NFK | Norfolk | England |
| NIR | Northern Ireland | Northern Ireland |
| NRY | North Riding of Yorkshire | England |
| NTH | Northamptonshire | England |
| NTT | Nottinghamshire | England |
| NYK | North Yorkshire | England |
| OFF | Co. Offaly | Ireland |
| OKI | Orkney | Scotland |
| OXF | Oxfordshire | England |
| PEE | Peebles-shire | Scotland |
| PEM | Pembrokeshire | Wales |
| PER | Perth | Scotland |
| POW | Powys | Wales |
| RAD | Radnorshire | Wales |
| RFW | Renfrewshire | Scotland |
| ROC | Ross and Cromarty | Scotland |
| ROS | Co. Roscommon | Ireland |
| ROX | Roxburghshire | Scotland |
| RUT | Rutland | England |
| SAL | Shropshire | England |
| SCT | Scotland | Scotland |
| SEL | Selkirkshire | Scotland |
| SFK | Suffolk | England |
| SGM | South Glamorgan | Wales |
| SHI | Shetland | Scotland |
| SLI | Co. Sligo | Ireland |
| SOM | Somerset | England |
| SRK | Sark | Channel Islands |
| SRY | Surrey | England |
| SSX | Sussex | England |
| STD | Strathclyde | Scotland |
| STI | Stirlingshire | Scotland |
| STS | Staffordshire | England |
| SUT | Sutherland | Scotland |
| SXE | East Sussex | England |
| SXW | West Sussex | England |
| SYK | South Yorkshire | England |
| TAY | Tayside | Scotland |
| TIP | Co. Tipperary | Ireland |
| TWR | Tyne and Wear | England |
| TYR | Co. Tyrone | Northern Ireland |
| WAL | Wales | Wales |
| WAR | Warwickshire | England |
| WAT | Co. Waterford | Ireland |
| WEM | Co. Westmeath | Ireland |
| WES | Westmorland | England |
| WEX | Co. Wexford | Ireland |
| WGM | West Glamorgan | Wales |
| WIC | Co. Wicklow | Ireland |
| WIG | Wigtownshire | Scotland |
| WIL | Wiltshire | England |
| WIS | Western Isles | Scotland |
| WLN | West Lothian | Scotland |
| WMD | West Midlands | England |
| WOR | Worcestershire | England |
| WRY | West Riding of Yorkshire | England |
| WYK | West Yorkshire | England |
| YKS | Yorkshire | England |