| Kunj Limited | Information & communication | 2013 |
| Kármán Research Ltd | Financial services | 2025 |
| L N Electrical Limited | Construction | 2006 |
| LA Bella Cleaning Company Ltd | Administrative & support | 2026 |
| Labrador Investments Limited | Wholesale & retail | 2014 |
| Lana Technology Limited | Information & communication | 2025 |
| Lancaster Court (Banstead) Limited | Households | 2003 |
| Lancelot Spratt Ltd | Health & social care | 2016 |
| Landlinx Property Consulting Limited | Construction | 2016 |
| Larklands Property Investments Ltd | Real estate | 2021 |
| Last Druid Coins Limited | Wholesale & retail | 2020 |
| Laura's Wellness Studio Limited | Other services | 2026 |
| LB Media Ltd | Information & communication | 2005 |
| LDH Weston Limited | Professional & scientific | 2016 |
| LDN Design and Build Ltd | Real estate | 2019 |
| Left Side Recordings Limited | Arts & recreation | 2023 |
| Legion Brickwork Ltd | Construction | 2016 |
| Leith Lake Consulting Ltd | Administrative & support | 2021 |
| LEK Group Ltd | Construction | 2019 |
| Leones Academica Ltd | Education | 2024 |
| Lepsus Solutions Limited | Information & communication | 2017 |
| Letts Recycle Limited | Administrative & support | 2019 |
| Lewis Stannard Racing Ltd | Arts & recreation | 2024 |
| LEX Globalis Ltd | Professional & scientific | 2024 |
| Liam Electrical LLP | | 2014 |
| Liberty ALB Limited | Administrative & support | 2022 |
| Like NO Other Clothing Ltd | Wholesale & retail | 2018 |
| Lillian Kelly Ltd | Professional & scientific | 2016 |
| Lime & Honey Ltd | Health & social care | 2023 |
| LIO London Ltd | Hospitality | 2018 |
| Little's Liquor Ltd | Hospitality | 2024 |
| Live Economics Ltd | Professional & scientific | 2017 |
| Livestrata Caldwell Ltd | Real estate | 2024 |
| Livestrata Ltd | Real estate | 2019 |
| LJB Events Ltd | Wholesale & retail | 2020 |
| LMC Developments Ltd | Construction | 2013 |
| Lockello Ltd | Administrative & support | 2014 |
| Locustworld Holdings Ltd | Information & communication | 2013 |
| Locustworld Limited | Information & communication | 2001 |
| London and Belcher Ltd | Wholesale & retail | 2020 |
| London Gymkhana Cricket Club CIC | Arts & recreation | 2014 |
| London Hard Landscapes Ltd | Administrative & support | 2016 |
| London Professional Ltd | Health & social care | 2016 |
| London Property Boards Limited | Professional & scientific | 2012 |
| Longcroft Consultancy Management Limited | Professional & scientific | 2007 |
| Longcroft Property Investments Limited | Real estate | 2016 |
| Longfield Crescent 1959 Limited | Extraterritorial | 2015 |
| Lordsgrove Management Company Limited | Households | 1993 |
| LP Monk Ltd | Information & communication | 2025 |
| LPL UK Tax Company Ltd | Professional & scientific | 2019 |
| LS Plastering & Building Ltd | Construction | 2026 |
| Luke Alex Marsh Ltd | Professional & scientific | 2023 |
| Luxe Creatives Limited | Professional & scientific | 2024 |
| Lwin Cienkusz Investment Limited | Real estate | 2023 |
| LXR Properties Ltd | Real estate | 2021 |
| M & T Decorators (Surrey) Ltd | Extraterritorial | 2019 |
| M J H Developments Cheam Road Limited | Construction | 2021 |
| M S Kalsi Properties (UK) Limited | Real estate | 2022 |
| M-Tek Group Limited | Construction | 2024 |
| M.A.M. Imaging Limited | Professional & scientific | 2003 |
| MAC Productions Ltd | Arts & recreation | 2025 |
| Macol Design and Development Ltd | Real estate | 2021 |
| Madisons Banstead Limited | Wholesale & retail | 2010 |
| Madr Property Ltd | Real estate | 2020 |
| Magna Partners Ltd | Real estate | 2020 |
| Mainline Plumbing Ltd | Construction | 2023 |
| Mainserv (London) Ltd | Administrative & support | 2024 |
| Maison Porte Limited | Manufacturing | 2026 |
| Make IT Real CF Ltd | Education | 2025 |
| Malinga Healthcare Ltd | Administrative & support | 2024 |
| Mamba Consulting Ltd | Professional & scientific | 2025 |
| Mamma MIA Pasta Bar Ltd | Hospitality | 2021 |
| MANA99 Ltd | Wholesale & retail | 2018 |
| Managed Language Limited | Professional & scientific | 2015 |
| Manta Media Ltd | Information & communication | 2024 |
| Mantech Sealants Supplier Limited | Construction | 2012 |
| Mantech Specialist Services Limited | Construction | 2015 |
| Marden & Co Accountants Limited | Professional & scientific | 2006 |
| Mark Barbrook Limited | Arts & recreation | 2011 |
| Marks Care Home Limited | Health & social care | 2017 |
| Martix Limited | Construction | 2015 |
| Marylebone Psychological Therapies Ltd | Extraterritorial | 2019 |
| Matlauzac Ltd | Health & social care | 2023 |
| Maven Consulting Group Ltd | Administrative & support | 2022 |
| MAY Retail Ltd | Wholesale & retail | 2019 |
| Mazeh Ltd | Hospitality | 2017 |
| MBS Assist Ltd | Professional & scientific | 2025 |
| Mcamc Ltd | Financial services | 2025 |
| Mckenzie Geospatial Surveys Limited | Professional & scientific | 2003 |
| Mcleod Wealth Management Limited | Financial services | 2017 |
| Mcmann and Tate Ltd | Health & social care | 2024 |
| MCQ Scaffolding Inspections Limited | Construction | 2018 |
| MCQ Scaffolding Limited | Construction | 2011 |
| Mcsherry Solutions Limited | Administrative & support | 2016 |
| Mcvee Motors Limited | Wholesale & retail | 1971 |
| MD Electrical Design & Build Ltd | Construction | 2026 |
| MD Engineering Consultancy Ltd | Professional & scientific | 2021 |
| MDA Digital Holdings Ltd | Professional & scientific | 2023 |
| MDA Training Limited | Professional & scientific | 1987 |
| Medora Health Limited | Health & social care | 2025 |