| Leeding Homes Ltd | Flamborough | — | — | Open → |
| Leeds City Council | Leeds | building.control@leeds.gov.uk | x | Open → |
| Leeds City Council | — | — | — | Open → |
| Leeds Construction Services Developments Ltd | Wakefield | — | — | Open → |
| LEEDS PROPERTIES | — | — | — | Open → |
| Leeds Properties Ltd | Leeds | — | — | Open → |
| Leeds Property Developments Ltd | Wokingham | — | — | Open → |
| Leicester City Council | Leicester | buildingcontrol@leicester.gov.uk | 0116 254 9922 | Open → |
| Leicestershire Fire & Rescue Service | Leicester | — | 0116 287 2241 | Open → |
| LEMASS | — | — | — | Open → |
| LEMASS | — | — | — | Open → |
| LEON SHIPLEY | — | — | — | Open → |
| Les Stuart | Wakefield | — | — | Open → |
| Lesley Harrison | Leeds | — | — | Open → |
| LEVEN PLAYING FIELDS ASSOCIATION | — | — | — | Open → |
| LEWIS | — | — | — | Open → |
| LEWIS BENTLEY DEVELOPMENTS | — | — | — | Open → |
| LF and EP Authority | London | — | — | Open → |
| LFCDA | Surrey | — | 0207 587 2644 | Open → |
| LFEPA - Kensington and Chelsea Borough Team | London | — | 0207 587 4811 | Open → |
| LGM Joinery | Leeds | i.robinson@hotmail.co.uk | — | Open → |
| LHL GROUP | — | — | — | Open → |
| LHL Group | Hull | jake.currie@lhlgroup.co.uk | 01482 215999 | Open → |
| Liam Hall | Leeds | liam_hall@sky.com | — | Open → |
| LIAM SMITH | — | — | — | Open → |