| Kalaro Ltd | Transport & logistics | 2017 |
| Kalnat Limited | Information & communication | 2017 |
| Kapadia Enterprises PVT Ltd | Wholesale & retail | 2011 |
| Kavir Corporation (UK) Ltd | Professional & scientific | 2020 |
| Kavitha Private Limited | Wholesale & retail | 2020 |
| KAY Travel Limited | Administrative & support | 2010 |
| Kay's Childminding Services Ltd | Other services | 2003 |
| Kell Building Contractors Limited | Construction | 1994 |
| Kennytv Ltd | Professional & scientific | 2017 |
| Kenrise Properties Ltd | Real estate | 2024 |
| Kerry O'Brien Limited | Wholesale & retail | 1999 |
| Kinetix Limited | Agriculture & fishing | 1995 |
| King COD Ltd | Hospitality | 2022 |
| KL Land Holdings Limited | Financial services | 2025 |
| Klarwasser Marin Technik Limited | Construction | 2012 |
| KO Mortgages Limited | Other services | 2007 |
| Komorebi Ventures Limited | Real estate | 2022 |
| Konch Consultancy Ltd | Professional & scientific | 2016 |
| Kryterion Limited | Education | 2011 |
| KS Propco Limited | Real estate | 2024 |
| KSB Energy Limited | Wholesale & retail | 2013 |
| Kudos Interior Designs Ltd | Wholesale & retail | 2024 |
| Kulcha Express London Ltd | Hospitality | 2019 |
| KVR Info Ltd | Information & communication | 2008 |
| LA Bodega Tapas Bar Limited | Hospitality | 2009 |
| LA Plaza Delicatessen Spanish Food & Wines Importers Ltd | Wholesale & retail | 2009 |
| LA Plaza Spanish Tapas Bar Limited | Hospitality | 2011 |
| Lakshmi Nivas Ltd | Real estate | 2021 |
| Lambda Therapeutic Limited | Professional & scientific | 2004 |
| Lampco Management Limited | Households | 2012 |
| Lanocorp UK Limited | Other services | 2010 |
| Laromed Limited | Health & social care | 2009 |
| Laurels(Nether Street)Management Limited(The) | Households | 1972 |
| LEH Consulting Limited | Professional & scientific | 2011 |
| LHG Trading Ltd | Professional & scientific | 2025 |
| Little Ladybirds Education Limited | Health & social care | 2017 |
| London College of Learning Limited | Education | 2021 |
| London Orthopaedic Surgeons Limited | Health & social care | 2010 |
| LRG Media Limited | Information & communication | 2009 |
| Luckyqueenie Empire Ltd | Professional & scientific | 2023 |
| Lujo Group Limited | Wholesale & retail | 2024 |
| LUX Management Services Limited | Households | 2021 |
| Lyceum Digital Ltd | Information & communication | 2000 |
| Lyceum Publishing Limited | Other services | 2004 |
| M & a Combine Limited | Wholesale & retail | 2000 |
| M D Patel Consultancy Limited | Professional & scientific | 2024 |
| M Stokes Consulting Ltd | Information & communication | 2016 |
| Maalush Limited | Manufacturing | 2024 |
| Magnum Car Company Limited | Wholesale & retail | 2025 |
| Maguire Company(Uk) Limited | Professional & scientific | 2024 |
| Mainstream Consultancy Ltd | Professional & scientific | 2020 |
| MAK GAS Ltd | Construction | 2017 |
| Marins Club Ltd | Hospitality | 2025 |
| Marketsandmarkets Limited | Professional & scientific | 2019 |
| Master Constructions Ltd | Construction | 2014 |
| Mayfair Mortgages Ltd | Financial services | 2018 |
| MB Property Finance Ltd | Financial services | 2012 |
| MB01 Lease Limited | Real estate | 2025 |
| Mbdr Holding Limited | Financial services | 2025 |
| Medwork Advisory Ltd | Health & social care | 2025 |
| Mehta Care Ltd | Health & social care | 2022 |
| Mercian Office Centres Limited | Real estate | 2019 |
| Miak Empire Ltd | Households | 2023 |
| Midasfrost Limited | Wholesale & retail | 2020 |
| Middx Investments Ltd | Real estate | 2019 |
| Mitreheath Limited | Professional & scientific | 1988 |
| Moorflagen Limited | Professional & scientific | 2022 |
| More Beauty Care Limited | Wholesale & retail | 2018 |
| Mount Atlas Limited | Real estate | 2017 |
| MPL Consultancy Ltd | Other services | 2023 |
| MR Grieves Originals Limited | Other services | 2015 |
| MR Roda Assets Ltd | Real estate | 2023 |
| MTW Watches Limited | Wholesale & retail | 2024 |
| MU Sigma International Limited | Financial services | 2018 |
| MU Sigma Limited | Information & communication | 2008 |
| Muslim Family Project Limited | Information & communication | 2022 |
| Nagpal Estates Ltd | Real estate | 2024 |
| News Box Asian Trader Ltd | Wholesale & retail | 2026 |
| Ngenious Solutions UK Limited | Information & communication | 2025 |
| NHL Builders Ltd | Construction | 2002 |
| Nicl Digital Limited | Professional & scientific | 2022 |
| Nicl Energy (CEE) Limited | Financial services | 2022 |
| Nikkita Limited | Transport & logistics | 2013 |
| Nikoomilana Ltd | Information & communication | 2019 |
| Nineferns Limited | Real estate | 2022 |
| Nitya Ltd | Construction | 2004 |
| Norfolk Endodontics Limited | Health & social care | 2012 |
| North Star Curators Ltd | Professional & scientific | 2025 |
| Nova Home Services Ltd | Construction | 2025 |
| Novalink Inc Ltd | Professional & scientific | 2025 |
| Novel Nutrientss Limited | Other services | 2018 |
| O'Meally Services Limited | Professional & scientific | 2007 |
| Omdaya Estates Limited | Hospitality | 2016 |
| ON the Edge Productions Ltd | Arts & recreation | 2023 |
| Only Care (Blackwell) Limited | Health & social care | 2021 |
| Only Care Property (Aylesbury) Ltd | Real estate | 2022 |
| Onyx Trade Post Limited | Real estate | 2003 |
| Optioncivil Limited | Households | 1987 |
| Optique 202O2 Limited | Wholesale & retail | 2001 |
| Oral Health Care & Education Ltd | Health & social care | 2025 |