| Code | Name |
|---|---|
| NIAT | Antrim |
| WSAPP | Appin |
| LCAPP | Appleby |
| NSAPP | Applecross |
| NDAPP | Appledore |
| MYAPP | Appleton Roebuck |
| LCAPB | Appley Bridge |
| THAFD | Arborfield Cross |
| ESARB | Arbroath |
| NDACO | Archers Court |
| WSARN | Arden |
| WSARY | Ardentinny |
| NSASR | Ardersier |
| NSAGY | Ardgay |
| NIAR | Ardglass |
| NSAGR | Ardgour |
| SDRDNGL | Ardingly |
| EAARD | Ardleigh |
| WSARD | Ardrossan |
| NSAVR | Ardvasar |
| WSARL | Ardwell |
| MRARD | Ardwick |
| NSARI | Arisaig |
| EMARKWR | Arkwright |
| MRARL | Arley Cheshire |
| WMARL | Arley Shropshire |
| ESARM | Armadale |
| NIAM | Armagh |
| LCARM | Armathwaite |
| CMARM | Armitage |
| MYARM | Armley |
| NIAY | Armoy |
| SLARM | Armthorpe |
| MYARN | Arncliffe |
| ESARN | Arncroach |
| EMARNOL | Arnold |
| LCASD | Arnside |
| WSARO | Aros |
| EAARR | Arrington |
| WSARR | Arrochar |
| LVARR | Arrowebrook |
| MYART | Arthington |
| SDRNDL | Arundel |
| THAS | Ascot |
| EMASFOR | Asfordby |
| NDASH | Ash |
| WMASH | Ash Bank |
| NDAGR | Ash Green |
| EMASBOU | Ashbourne |
| WWASHB | Ashburton |
