| Lighthouse Automotive Limited | Real estate | 2015 |
| Lighthouse Project Management Ltd | Administrative & support | 2022 |
| Lightyear Footwear Limited | Administrative & support | 2024 |
| Liney's Floral Decor Ltd | Construction | 2013 |
| Lingerfield Garage Ltd | Wholesale & retail | 2019 |
| Linksclothingco Ltd | Wholesale & retail | 2025 |
| Liquid Hi-Fi Limited | Extraterritorial | 2001 |
| Little Big Creative Agency Ltd | Professional & scientific | 2024 |
| Little Darlings Toys Ltd | Wholesale & retail | 2016 |
| Little OWL Events Limited | Hospitality | 2025 |
| Livius Events Limited | Administrative & support | 2010 |
| LJ Landscaping Ltd | Professional & scientific | 2025 |
| Local Schoolwear Centre Limited | Extraterritorial | 2010 |
| Locum Four Eyes Ltd | Health & social care | 2023 |
| Lodge Cottage Ltd | Hospitality | 2003 |
| Lodgepad Properties Ltd | Real estate | 2021 |
| Longhills Properties Limited | Real estate | 2017 |
| Lookatmycv Limited | Other services | 2018 |
| Loudon Construction Ltd | Construction | 2018 |
| LPB Property Ltd | Real estate | 2023 |
| LPV Coppergate Ltd | Real estate | 2007 |
| LS11 Limited | Real estate | 2016 |
| Lucky Bean Media Ltd | Information & communication | 2026 |
| Luga Menston Limited | Real estate | 2007 |
| Luga Parliament House Limited | Real estate | 2006 |
| Luga Properties Limited | Real estate | 2005 |
| Lukas Isaac Ltd | Information & communication | 2015 |
| Luke Ayling Football Academy Ltd | Arts & recreation | 2025 |
| Lukepook Properties Ltd | Real estate | 2023 |
| Lullaby Lane Children's Boutique Ltd | Wholesale & retail | 2026 |
| Lusso Concierge (Group) Ltd | Other services | 2022 |
| LV Properties (Leeds) Ltd | Real estate | 2019 |
| LV Property Holdings Ltd | Real estate | 2018 |
| Lydiam Holdings Ltd | Real estate | 2021 |
| Lyth Valley Property Services Ltd | Real estate | 2014 |
| M&M Finances Ltd | Professional & scientific | 2023 |
| M.H. Whittaker & SON (Holdings) Limited | Real estate | 1960 |
| Macg Racing (GT Cars) Ltd | Wholesale & retail | 2018 |
| Machnamh Ltd | Health & social care | 2019 |
| Mackem Allwright Consulting Ltd | Professional & scientific | 2019 |
| Made - Terraneo Ltd | Wholesale & retail | 2017 |
| Madeline Aviation LLP | | 2020 |
| Madison Media Limited | Professional & scientific | 2023 |
| Mafl Limited | Arts & recreation | 2012 |
| Maison Noir Group Ltd | Wholesale & retail | 2025 |
| MAL Investcom Ltd | Professional & scientific | 2022 |
| Management Company the Pines Ltd | Households | 2023 |
| Mangan Estates Limited | Construction | 2005 |
| Manne Properties Ltd | Real estate | 2025 |
| Manor Early Years Pre-School Limited | Education | 2013 |
| Manor Park (Arkendale) Management Company Limited | Households | 1984 |
| Manse Mews Management Company Limited | Households | 2014 |
| Manyu Solidarity Limited | Other services | 2023 |
| Maple Red Limited | Professional & scientific | 2008 |
| Maple Subway Limited | Hospitality | 2017 |
| Marigold Boats Limited | Administrative & support | 2026 |
| Marlon's House LLP | | 2022 |
| Marshall Catering Services Limited | Manufacturing | 1991 |
| Marsland Grout Ltd | Construction | 2022 |
| Martial Arts for Life Limited Liability Partnership | | 2010 |
| Martingale Estates Limited | Construction | 2007 |
| Matt Barnes Digital Ltd | Information & communication | 2023 |
| Matthew Sowerby Ltd | Real estate | 2025 |
| MAX Plant Yorkshire Limited | Manufacturing | 2025 |
| Max-Link Solutions Ltd | Wholesale & retail | 2021 |
| Maypole Digital Limited | Information & communication | 2023 |
| MBP Medical Consulting Ltd | Professional & scientific | 2022 |
| Mcbride Property Ltd | Real estate | 2021 |
| Mcmillan Joinery Ltd | Construction | 2026 |
| Mcwinnie Property Group Ltd | Construction | 2022 |
| MDA Property Developments Limited | Construction | 1991 |
| MDE UK Limited | Professional & scientific | 2003 |
| Meadley Square Ltd | Households | 2024 |
| Medikarri UK Ltd | Manufacturing | 2024 |
| Medisum Limited | Administrative & support | 2014 |
| Medusa Investments Ltd | Financial services | 2024 |
| Meehan Corporate Consulting Limited | Professional & scientific | 2008 |
| Meliora PSC Ltd | Professional & scientific | 2023 |
| Merrell Consulting Limited | Professional & scientific | 2019 |
| Mervyn Hart Limited | Real estate | 2017 |
| Metro Technologies Ltd | Information & communication | 2023 |
| MGH Garden Services Ltd | Administrative & support | 2026 |
| Miche Clean Ltd | Wholesale & retail | 2019 |
| Michelle Hyett Design Ltd | Professional & scientific | 2021 |
| Midmos Solutions Limited | Manufacturing | 2003 |
| Mika Hawi Ltd | Wholesale & retail | 2023 |
| Mikeson Ltd | Real estate | 2023 |
| Milby Properties Limited | Real estate | 2004 |
| Mindful Creations 72 CIC | Hospitality | 2026 |
| Minerva FS Ltd | Financial services | 2020 |
| MJ Ryder Limited | Construction | 2006 |
| Mjra Accountancy Services Limited | Professional & scientific | 2022 |
| MMC Recruitment Limited | Administrative & support | 2015 |
| Mmcengineer Ltd | Professional & scientific | 2015 |
| Mmid Properties Ltd | Real estate | 2021 |
| Modern Engineered Software Solutions Ltd. | Information & communication | 2014 |
| Monarchy Care Services Ltd | Hospitality | 2017 |
| Mondon Group Ltd | Real estate | 2025 |
| Monkswell Business Centre Limited | Real estate | 2024 |
| Monteys (Harrogate) Limited | Hospitality | 2010 |