| Little Hawkes Ltd | Wholesale & retail | 2021 |
| Little Quirky Creative Ltd | Professional & scientific | 2023 |
| Live Wild Birth Free Ltd | Education | 2024 |
| Live With Care Ltd | Health & social care | 2023 |
| Livefromlondon Limited | Health & social care | 2014 |
| Livingwell Home Support Limited | Health & social care | 2025 |
| LJ Cleaning Services (UK) Ltd | Administrative & support | 2014 |
| LJO Damp Proofing Limited | Construction | 2014 |
| LK Construction London Limited | Construction | 2017 |
| LKT Communications Ltd | Information & communication | 2026 |
| Lloyd Pipefitting & Welding Limited | Construction | 1998 |
| Lloyds Travel Limited | Real estate | 1996 |
| LM Consult Limited | Professional & scientific | 2009 |
| LM London Carpentry Ltd | Manufacturing | 2019 |
| LM Mediation Ltd | Professional & scientific | 2026 |
| LM25 Estates Limited | Real estate | 2026 |
| Lmdt Limited | Education | 2020 |
| LMF Properties Investment Ltd | Real estate | 2020 |
| LMG Estates Limited | Real estate | 2008 |
| LND Real Estate Ltd | Real estate | 2018 |
| Local Leisure Limited | Hospitality | 1987 |
| Locked Store Limited | Information & communication | 2024 |
| Lodge Drive Management Limited | Administrative & support | 1985 |
| Lofthouse Services Limited | Administrative & support | 2023 |
| Logie Property Portfolio Limited | Real estate | 2023 |
| Logondotcom Ltd | Information & communication | 2002 |
| London & Middlesex Media Group Limited | Professional & scientific | 1960 |
| London Adelaide Properties Limited | Real estate | 2019 |
| London Business Training Ltd | Education | 2015 |
| London Funfairs Ltd | Arts & recreation | 2017 |
| London Holiday Camps Ltd | Health & social care | 2021 |
| London Mode Beauty Ltd | Other services | 2023 |
| London New Build Superhomes Ltd | Construction | 2026 |
| London Property Maintenance Services Ltd | Construction | 2026 |
| London PUB Theatres Magazine Limited | Information & communication | 2016 |
| London Region Arts Club | Education | 1986 |
| London Scaffold Alarms Limited | Construction | 2015 |
| London Wealth Management Limited | Financial services | 2008 |
| Longer Rise Engineering Ltd | Construction | 2018 |
| Longhurst & SON M&E Ltd | Construction | 2025 |
| Longmeads Freehold Ltd | Real estate | 2023 |
| Longonot Investments Limited | Real estate | 2019 |
| Lorrimer-Roberts Property Limited | Real estate | 2021 |
| Lost Stolen Dog Ltd | Other services | 2021 |
| Lotay Ltd | Health & social care | 2022 |
| Lotus Living London Ltd | Households | 2022 |
| Lotus Property Group Ltd | Real estate | 2021 |
| Loudwater (Trout Rise Farm) Limited | Real estate | 2014 |
| Loudwater (Troutstream) Estate Limited | Real estate | 1957 |
| Loudwater Freehold Estates Limited | Real estate | 2008 |
| Loudwater House Limited | Households | 1995 |
| Lovetalks Limited | Other services | 2021 |
| Lower Plantation (Management Company) Limited | Households | 1986 |
| LPL Holdings Limited | Financial services | 2018 |
| LRC Consultancy Services Limited | Professional & scientific | 2023 |
| LRG Holdco Limited | Financial services | 2025 |
| LS Investors Limited | Real estate | 2024 |
| LT Accounting Limited | Professional & scientific | 2021 |
| Ltmd Garage Ltd | Wholesale & retail | 2026 |
| Luca Montanino Limited | Hospitality | 2017 |
| Lucas's Management Company Limited | Real estate | 2021 |
| Lucidant Consulting Ltd | Professional & scientific | 2023 |
| Lucky Dragon Limited | Real estate | 2025 |
| Lucus Consultancy Limited | Other services | 2020 |
| Lumen Manser Limited | Administrative & support | 1996 |
| Lumera Consulting Ltd | Information & communication | 2019 |
| Luminux Studio Ltd | Professional & scientific | 2021 |
| Luna Automation Limited | Information & communication | 2017 |
| Luxe Destinations Limited | Professional & scientific | 2024 |
| Luxfam Limited | Wholesale & retail | 2015 |
| Luxury Country Living Ltd | Construction | 2020 |
| Luxury Investments Group Limited | Wholesale & retail | 2024 |
| LV Fitt Ltd | Arts & recreation | 2019 |
| Lycodia Limited | Information & communication | 2002 |
| Lymington Precision Engineering (LPE) Limited | Manufacturing | 2011 |
| Lymington Precision Engineers Co. Limited | Manufacturing | 1981 |
| Lyon Square Commercial Ltd | Construction | 2018 |
| M & J Ventures Limited | Financial services | 2025 |
| M & M Efficient Solutions Limited | Professional & scientific | 2019 |
| M & P Developments (Streatham) Ltd | Real estate | 2015 |
| M a Kiss Carpentry Ltd | Construction | 2025 |
| M C Landscaping Ltd | Administrative & support | 2020 |
| M C Property Services (Herts) Limited | Administrative & support | 2012 |
| M J Prime Lettings Ltd | Real estate | 2021 |
| M J Prime Property Ltd | Real estate | 2020 |
| M K Damp and Timber Ltd | Construction | 2022 |
| M S Dental Care Ltd | Health & social care | 2022 |
| M Walsh Flooring Ltd | Construction | 2021 |
| M&W Grazebrook Limited | Professional & scientific | 1968 |
| M.& R.Bowman Limited | Construction | 1963 |
| M25 Cleaning Ltd | Administrative & support | 2024 |
| Maass Foods Ltd | Hospitality | 2025 |
| Mabel & James Ltd | Professional & scientific | 2016 |
| MACAW75 Ltd | Information & communication | 2025 |
| Mache Interiors Limited | Professional & scientific | 2023 |
| MAD Dog Construction Limited | Construction | 2018 |
| MAD Dog Developers Limited | Construction | 2014 |
| MAD Moon Vintage Limited | Arts & recreation | 2014 |
| Maddie and Friends Ltd | Information & communication | 2023 |
| Maddy Hinton Casting Limited | Administrative & support | 2012 |