| Code | Name | Region |
|---|---|---|
| GBZBY | Magherfelt | |
| GBMGL | Maghull | SFT |
| GBMGP | Magilligan Point Ferry Terminal, Lough Foyle | LMV |
| GBMAG | Magor | MON |
| GBMDV | Maida Vale/london | BEN |
| GBMBD | Maiden Bradley | WIL |
| GBLMM | Lymm | CHE |
| GBLYN | Lympne | KEN |
| GBLPM | Lympsham | SOM |
| GBLYH | Lyndhurst | HAM |
| GBLNE | Lyne | SRY |
| GBLYE | Lyneham | WIL |
| GBLMO | Lynemouth | NBL |
| GBLYS | Lyness | ORK |
| GBLNM | Lynmouth | |
| GBLYT | Lynton | DEV |
| GBYHL | Lyonshall | HEF |
| GBLCM | Lytchett Minster | DOR |
| GBLYA | Lytham Saint Annes | LAN |
| GBMTP | Mablethorpe | LIN |
| GBMCL | Macclesfield | CHE |
| GBMCD | Macduff | ABD |
| GBMCN | Machen | CAY |
| GBMAC | Machrihanish | AGB |
| GBMNL | Machynlleth | POW |
| GBXMA | Mackworth | DBY |
| GBLL3 | Lullington | DBY |
| GBLUL | Lulworth Camp | DOR |
| GBLWC | Lulworth Cove | DOR |
| GBUND | Lund | ERY |
| GBURL | Lurgan | ARM |
| GBLUT | Luton | CBF |
| GBLTT | Lutterworth | LEC |
| GBLXG | Luxborough | SOM |
| GBLUX | Luxulyan | CON |
| GBLYB | Lybster | HLD |
| GBYDB | Lydbury North | SHR |
| GBLYX | Lydd | KEN |
| GBYOS | Lydd On Sea | KEN |
| GBLY9 | Lydden | KEN |
| GBLDT | Lydiate | SFT |
| GBLYD | Lydney | GLS |
| GBLIE | Lye | DUD |
| GBLYR | Lyme Regis | DOR |
| GBLYM | Lymington | HAM |
| GBLMR | Lyminster | WSX |
| GBLHN | Loughton | ESS |
| GBLOD | Lound | NTT |
| GBLUN | Lount | LEC |
| GBLOT | Louth | LIN |