| Kfrw Limited | Real estate | 2022 |
| KG Security Limited | Construction | 2004 |
| Kgntraining Limited | Arts & recreation | 2015 |
| Khan Architecture Limited | Professional & scientific | 2010 |
| KI Enterprises Ltd | Professional & scientific | 2016 |
| Kingsilver Capital Ltd | Financial services | 2024 |
| Kinsera Residential Care Ltd | Health & social care | 2026 |
| Kitza Productions Ltd | Information & communication | 2024 |
| KK Buckhurst Hill Ltd | Hospitality | 2025 |
| Kkdistros Ltd | Wholesale & retail | 2025 |
| KKS Lettings Limited | Real estate | 2017 |
| KL Co Trading Ltd | Health & social care | 2010 |
| Klarity AV Limited | Financial services | 2022 |
| Klco Ltd | Real estate | 2020 |
| KMI Recruitment Limited | Administrative & support | 2020 |
| Kmpr Ltd | Professional & scientific | 2025 |
| Knighton Corner Residents Association Limited | Households | 2010 |
| Knighton Gate Ltd | Extraterritorial | 2015 |
| Knighton Woods Movement Group CIC | Arts & recreation | 2025 |
| Knightons Investments Limited | Real estate | 2025 |
| Knolls Hill Management Company Limited | Real estate | 2004 |
| Knots & DYE Ltd | Other services | 2018 |
| Kobigan Properties Ltd | Real estate | 2020 |
| Kompare Limited | Information & communication | 2017 |
| Konnectright Ltd | Administrative & support | 2025 |
| Kool Taste Limited | Manufacturing | 2013 |
| Koveru Limited | Financial services | 2026 |
| KP Elevations Ltd | Health & social care | 2025 |
| Kwoter Limited | Information & communication | 2017 |
| Kyinkyinga Ltd | Hospitality | 2026 |
| L & L Contracting Ltd | Construction | 2019 |
| L&M Cleaning Ltd | Administrative & support | 2025 |
| Lach Limited | Information & communication | 2023 |
| Ladztuff Ltd | Administrative & support | 2013 |
| Lamblords Estates Limited | Real estate | 2025 |
| Larkhall Place LLP | | 2026 |
| Lasted Limited | Real estate | 2011 |
| Laticauda Ltd | Professional & scientific | 2020 |
| Laura Logistics Ltd | Construction | 2019 |
| LAV Capital Limited | Professional & scientific | 2025 |
| LB Sports Limited | Professional & scientific | 2024 |
| LCW Consultancy Services Ltd | Other services | 2023 |
| LDF Supply Limited | Wholesale & retail | 2025 |
| LDS UK Solutions Ltd | Transport & logistics | 2015 |
| Learnforce Limited | Real estate | 1984 |
| Lecca Plumbing & Heating Ltd | Information & communication | 2024 |
| LEE & Sons (Essex) Limited | Wholesale & retail | 2022 |
| LEE London Ltd | Real estate | 2019 |
| Legal Penguin Ltd | Professional & scientific | 2024 |
| Legood & Knight Construction Limited | Construction | 2024 |
| Leopard & Keys Ltd | Real estate | 2026 |
| Lettingspace Limited | Real estate | 2006 |
| Levi Arch Limited | Wholesale & retail | 2025 |
| Life Discipline Limited | Health & social care | 2024 |
| Lifetouchers Ltd | Information & communication | 2015 |
| Ligas (Service to Industry) Limited | Manufacturing | 1978 |
| Ligas Nitrogen Services Limited | Other services | 2004 |
| Lights and Glows Limited | Wholesale & retail | 2019 |
| Lili Lakatos Ltd | Transport & logistics | 2025 |
| Lily Learning Centre Limited | Extraterritorial | 2016 |
| Lilylox Limited | Wholesale & retail | 2010 |
| Link Pro Recruitment Limited | Administrative & support | 2019 |
| Link Productions Limited | Information & communication | 2005 |
| Lionhead Productions Limited | Arts & recreation | 1980 |
| Little Bridge Limited | Information & communication | 2006 |
| Little Gems Wellbeing Centre Limited | Education | 2024 |
| LJ Mace Consulting Limited | Professional & scientific | 2024 |
| LKW Haulage Ltd | Transport & logistics | 2025 |
| LMP Electrical Systems Ltd | Construction | 2020 |
| Load In-Load OUT Ltd | Hospitality | 2026 |
| Lobster IT Limited | Information & communication | 2013 |
| Loki Acquisitions Limited | Financial services | 2023 |
| LOL Jewellery Limited | Manufacturing | 2016 |
| London & Essex Cleaning Services Ltd | Transport & logistics | 2020 |
| London and South Eastern Property Company Limited | Real estate | 2021 |
| London Building Surveyors Ltd | Other services | 2015 |
| London City Estates Ltd | Administrative & support | 2014 |
| London Elita Limited | Other services | 2014 |
| London Fields Electrical Services Limited | Construction | 2023 |
| London Fields Estates Limited | Construction | 2019 |
| London Music Talents LLP | | 2025 |
| London Road Valeting Ltd | Other services | 2026 |
| London Smart Build Management Ltd | Construction | 2018 |
| London Tax Accountant Limited | Professional & scientific | 2012 |
| Longhand Pictures Limited | Arts & recreation | 2019 |
| Looric Property Limited | Real estate | 2023 |
| Lopes & Domingos Ltd | Hospitality | 2020 |
| Lordship Estates Ltd | Real estate | 2017 |
| Lost Pictures Limited | Information & communication | 2011 |
| Loughton Caffe Bar Ltd | Hospitality | 2024 |
| Loughton Landscapes Ltd | Administrative & support | 2021 |
| Loughton Way News Ltd | Wholesale & retail | 2026 |
| Loughton, Buckhurst Hill and Chigwell Primary Care Network Limited | Health & social care | 2020 |
| Louis Frank's Property Services Ltd | Real estate | 2025 |
| Louise Garner Consultancy Ltd | Professional & scientific | 2013 |
| LOVE4NATURE Ltd | Professional & scientific | 2023 |
| Lovetheworld CIC | Other services | 2022 |
| Lrbfs Ltd | Wholesale & retail | 2023 |
| LUC Logistics Ltd | Transport & logistics | 2020 |
| Lunivaa Ltd | Professional & scientific | 2025 |