| JAE Recruitment Ltd | Public administration | 2024 |
| Jaguson Construction Ltd | Construction | 2021 |
| Jaguson Property Investments Ltd | Real estate | 2022 |
| Jay's Food Limited | Wholesale & retail | 2019 |
| Jay's Investment Ltd | Real estate | 2001 |
| JBA Properties Ltd | Real estate | 2022 |
| JET Renovation London Ltd | Construction | 2025 |
| John Crook & Partners LLP | | 2025 |
| John Mackie Greengrocers Limited | Wholesale & retail | 2013 |
| Jolly's Catering Limited | Administrative & support | 2016 |
| Jolly's Sandwich Bar Limited | Hospitality | 2011 |
| Jollys at RAD Limited | Administrative & support | 2017 |
| JT Homes Ltd | Real estate | 2024 |
| K & G Property Investments Ltd | Real estate | 2016 |
| K H Group Limited | Financial services | 2022 |
| K W Carpentry & Building Limited | Construction | 2003 |
| Kaizzen Consultancy Ltd | Professional & scientific | 2026 |
| Kaplan Security Limited | Administrative & support | 2014 |
| KDS Consultancy Limited | Health & social care | 2022 |
| Kensington Investment Advisors Limited | Financial services | 2021 |
| Kesk Investment Ltd | Real estate | 2022 |
| Ketz UK Limited | Professional & scientific | 2019 |
| Kibriz Restaurant Ltd | Hospitality | 2024 |
| King & Henry Limited | Professional & scientific | 2007 |
| KIR Restaurant Limited | Hospitality | 2018 |
| Kiri Designs Limited | Manufacturing | 2008 |
| Kiri Glamorous Ltd | Wholesale & retail | 2021 |
| KK Parts & Car Sales (UK) Ltd | Wholesale & retail | 2019 |
| KMP Estates Limited | Real estate | 2006 |
| Koch Brothers Limited | Hospitality | 2016 |
| Kodeas Ltd | Information & communication | 2020 |
| KRH Tech Ltd | Real estate | 2021 |
| Kubsi Limited | Professional & scientific | 2015 |
| L & J Heating Limited | Construction | 2016 |
| L R L Property Services Limited | Construction | 2005 |
| L.S.A Investments Ltd | Real estate | 2024 |
| Lakeside Nursery Limited | Agriculture & fishing | 2011 |
| Lancaster Wills & Trusts Ltd | Professional & scientific | 2012 |
| Landscape Machine Limited | Construction | 2018 |
| Langley Hill Investments Limited | Financial services | 2015 |
| Languageuk Limited | Education | 2007 |
| Latcham Commercial Services Limited | Professional & scientific | 2014 |
| Layes Holdings Ltd | Real estate | 2021 |
| Lazarou Investments Ltd | Real estate | 2026 |
| LDS Building Co Ltd | Construction | 2019 |
| Lello Invest Limited | Extraterritorial | 2015 |
| Lemon IT Limited | Information & communication | 2015 |
| Lens Marketing Ltd | Professional & scientific | 2020 |
| Lepton Consulting Ltd | Information & communication | 2018 |
| LET Haven Ltd | Real estate | 2026 |
| Lets Move Inn Limited | Real estate | 2011 |
| Letsdoit Properties Limited | Construction | 2006 |
| Lexi Property Investment Ltd | Real estate | 2018 |
| Lica Construction Ltd | Construction | 2025 |
| Likya Groceries Ltd | Wholesale & retail | 2020 |
| Linden Stores Ltd | Hospitality | 2017 |
| Line Infinity Limited | Construction | 2014 |
| Link Personnel Limited | Administrative & support | 2014 |
| Lires Ltd | Wholesale & retail | 2018 |
| LK Dwelling Rise Limited | Construction | 2011 |
| LOA Sales Ltd | Wholesale & retail | 2011 |
| Logic Global Events Limited | Administrative & support | 2015 |
| London Plumbing Direct Ltd | Construction | 2020 |
| Lowrie Limited | Professional & scientific | 2010 |
| Lukson Contractors Ltd | Construction | 2025 |
| Lumen Haven Ltd | Manufacturing | 2025 |
| Luminary Fine Jewellery Limited | Professional & scientific | 2020 |
| M 77 SEN Limited | Real estate | 2017 |
| M T P Consultancy Ltd | Professional & scientific | 2026 |
| M T P Media Ltd | Professional & scientific | 2024 |
| M W Carroll & Sons Ltd | Other services | 2018 |
| M.E.E.D. (London) Ltd | Transport & logistics | 2017 |
| M.G. Engineering & Maintenance Limited | Construction | 2011 |
| Magic Homes Ltd. | Real estate | 2002 |
| Major Events & Band Limited | Other services | 2019 |
| Manos EAT Greek Ltd | Hospitality | 2023 |
| Market Place (London) Holdings Ltd | Real estate | 2020 |
| Marylou Handmade Ltd | Manufacturing | 2024 |
| Mast Building Services Ltd | Construction | 2024 |
| Maxiwork Engineering Limited | Construction | 1998 |
| Mceb Limited | Professional & scientific | 2018 |
| MD Lighting Limited | Construction | 2011 |
| MDG Property Ltd | Real estate | 2020 |
| Mdgs Properties Limited | Real estate | 2016 |
| Media Technology Ltd | Manufacturing | 2023 |
| Medical Business Compliance Ltd | Wholesale & retail | 2020 |
| Medium Rare Films Ltd | Information & communication | 2011 |
| Medrida Ltd | Hospitality | 2017 |
| Melden Limited | Administrative & support | 2018 |
| Melina (London) Ltd | Wholesale & retail | 2022 |
| Mellrose Ltd | Other services | 2019 |
| MEM Plumbing & Electrical Limited | Construction | 2015 |
| Metra Surveying Limited | Professional & scientific | 2018 |
| METRICS34 UK Limited | Professional & scientific | 2018 |
| MEX Haircare Ltd | Wholesale & retail | 2019 |
| MGA Plus Limited | Other services | 2019 |
| MGM Dining Ltd | Hospitality | 2025 |
| MHB Hair Consultancy Ltd | Wholesale & retail | 2021 |
| Miago Academy Limited | Education | 2025 |
| Michael Palfreman Limited | Financial services | 2017 |