| Kingston Housing Ltd | Real estate | 2022 |
| Kirandht Ltd | Health & social care | 2026 |
| Kitchens and Bathrooms MK Ltd | Wholesale & retail | 2019 |
| Kivulini Limited | Information & communication | 2021 |
| KJ Body Repair Centre Ltd | Wholesale & retail | 2023 |
| Klementina Events and Decor Ltd | Arts & recreation | 2023 |
| KN Dental Ltd | Health & social care | 2025 |
| Kobby K9 Limited | Transport & logistics | 2025 |
| Koko Medispa Ltd | Health & social care | 2017 |
| Kong Building Developments Ltd | Other services | 2020 |
| Kongens Partnerships Ltd | Wholesale & retail | 2024 |
| Konig Car Storage and Transportation Limited | Transport & logistics | 1997 |
| Kostas & Bross Tiling Ltd | Construction | 2021 |
| KPI Evolution Limited | Professional & scientific | 2021 |
| Kunbri Holdings Limited | Real estate | 2017 |
| L Alexandra Co Ltd | Wholesale & retail | 2025 |
| L&A Enterprises Limited | Professional & scientific | 2014 |
| L.S Connell Limited | Construction | 2016 |
| Lacuna Ventures Ltd | Financial services | 2018 |
| Lakin Ogunbanwo Studio Ltd | Information & communication | 2025 |
| Lame Skateboards Ltd | Wholesale & retail | 2020 |
| Landmark (MK) Management Limited | Households | 2007 |
| Landmark 29-01 Limited | Extraterritorial | 2010 |
| Landmark 29-02 Limited | Real estate | 2010 |
| Landmark 29-03 Limited | Real estate | 2010 |
| Landmark 301 Limited | Real estate | 2010 |
| Landmark 302 Limited | Real estate | 2010 |
| Landmark 303 Limited | Extraterritorial | 2010 |
| Landmark 304 Limited | Real estate | 2010 |
| Landmark 305 Limited | Real estate | 2010 |
| Landmark 306 Limited | Real estate | 2010 |
| Landmark C9 Ltd | Real estate | 2015 |
| Landmark Daventry Limited | Administrative & support | 2018 |
| Landmark G2 Ltd | Real estate | 2015 |
| Landmark Hospitality Limited | Hospitality | 2019 |
| Landons Close Freehold Limited | Real estate | 2012 |
| Larchfield Day Nursery Limited | Health & social care | 2021 |
| Large Hospitality Ltd | Real estate | 2018 |
| Lary Company General Services Ltd | Construction | 2019 |
| LAS Motorhomes Ltd | Extraterritorial | 2004 |
| Lastbeat Limited | Other services | 2005 |
| Lavaclose Limited | Households | 1986 |
| Lavanya Services Ltd | Construction | 2025 |
| LAW2024 Limited | Professional & scientific | 2018 |
| Lazy Loop Studio Ltd | Wholesale & retail | 2021 |
| LEE Nulty Electrical Ltd | Construction | 2021 |
| Legacy Protect Limited | Professional & scientific | 2012 |
| Lembrook Limited | Real estate | 1977 |
| Lesley Colin's Limited | Hospitality | 2025 |
| LET Rose Ltd | Real estate | 2024 |
| Lets Go Build Ltd | Construction | 2025 |
| Lets Go Limited | Real estate | 2023 |
| Letsetgo Ltd | Real estate | 2025 |
| Lettings MK Limited | Real estate | 2019 |
| Lewis Smith Coachwork Ltd | Manufacturing | 2023 |
| Lianne Scallan Skincare Ltd | Other services | 2025 |
| Lightning Process Limited | Education | 2007 |
| Lillibet Manor Limited | Real estate | 2011 |
| Lilypots Pottery and Crafts Ltd | Wholesale & retail | 2026 |
| Lincoln Park Management Limited | Households | 1988 |
| Little Barnyard Cafe Ltd | Hospitality | 2026 |
| Livewire Band UK Ltd | Arts & recreation | 2020 |
| Livingstone Seagull Limited | Information & communication | 1989 |
| LIZ Investment Portfolio Limited | Real estate | 2025 |
| Llst Ltd. | Information & communication | 2018 |
| LNF Letting Services Ltd | Financial services | 2025 |
| LNF Property Investments Ltd | Real estate | 2025 |
| Loaf Plus Limited | Wholesale & retail | 2019 |
| Lockhart Travel Limited | Administrative & support | 2025 |
| London Vehicle Hire Ltd | Administrative & support | 2020 |
| Longueville Court Limited | Administrative & support | 2019 |
| Lords Rail Ltd | Manufacturing | 2019 |
| Love Surveying Limited | Professional & scientific | 2021 |
| LQ Estates Limited | Real estate | 2012 |
| Luckett Property Holdings Ltd | Real estate | 2025 |
| Luckley Cottages Limited | Administrative & support | 2019 |
| Luckley Holdings Limited | Administrative & support | 2020 |
| Ludwick Precision Holdings Limited | Financial services | 2019 |
| Ludwick Precision Ltd | Manufacturing | 1999 |
| Lumensol Accounting Ltd | Professional & scientific | 2019 |
| Lumensol Ltd | Professional & scientific | 2018 |
| Luna Property Services Ltd | Real estate | 2018 |
| Luxwood UK Limited | Manufacturing | 2025 |
| Lydia Sky Ltd | Transport & logistics | 2025 |
| M & E Heating Contracts Ltd | Construction | 2016 |
| M & K Beresford Ltd | Real estate | 2022 |
| M&Ad Ltd | Manufacturing | 2015 |
| M1 Scaffolding Limited | Construction | 2013 |
| MA Cutz Ltd | Other services | 2021 |
| MAC Mcculley Consultancy Limited | Extraterritorial | 2010 |
| Maccabi House Management Company Ltd | Households | 2001 |
| Macmk Ltd | Administrative & support | 2021 |
| Maddison Games Limited | Wholesale & retail | 2003 |
| Magic Words Therapy Limited | Health & social care | 2013 |
| Maison DE Cuisson Ltd | Hospitality | 2024 |
| Majestic Living Ltd | Real estate | 2016 |
| MAK Chishty Consultancy Limited | Administrative & support | 2017 |
| Makers Mansion Ltd | Administrative & support | 2018 |
| Maltmoor Limited | Real estate | 2004 |
| Mamaluv's Kitchen Limited | Hospitality | 2025 |