| Luxeheat Plumbing & Heating Ltd | Construction | 2023 |
| Luxline Taxi Chichester Ltd | Transport & logistics | 2025 |
| Luxore Private Limited | Wholesale & retail | 2025 |
| Luxury Lashes Agnes Ltd | Other services | 2023 |
| Luxury Lawns Ltd | Professional & scientific | 2015 |
| Luxury Prize Group Limited | Other services | 2025 |
| Luxury Retail Consulting Ltd | Professional & scientific | 2018 |
| Luxury Supercars London Ltd | Administrative & support | 2024 |
| Lventures Trading Ltd | Extraterritorial | 2024 |
| LVZ Automation Limited | Construction | 1993 |
| LVZ Horticultural Limited | Manufacturing | 2006 |
| Lwgardening Ltd | Administrative & support | 2022 |
| Lwpg 2026 Limited | Hospitality | 2026 |
| Lwpg Holdings Limited | Financial services | 2026 |
| Lydell Jewellery Services Ltd | Wholesale & retail | 2011 |
| Lynch Down Residents Association Limited | Households | 1973 |
| Lynchmere Cottages Management Company Limited | Households | 2002 |
| Lyndhurst Place Management Company Ltd | Households | 2019 |
| Lynk Contract Services Limited | Administrative & support | 2014 |
| Lyons Group Holdings Limited | Financial services | 2008 |
| M & a Monitor Limited | Information & communication | 1992 |
| M & B Creative Limited | Arts & recreation | 2013 |
| M & T Chichester Limited | Other services | 2014 |
| M B Motors (Midhurst) Ltd | Wholesale & retail | 2013 |
| M F Brown Ltd | Construction | 2013 |
| M G J Property Services Ltd | Real estate | 2004 |
| M H Heating Ltd | Construction | 2007 |
| M H Withers Limited | Health & social care | 2002 |
| M J O Forestry Limited | Agriculture & fishing | 2003 |
| M J Visual Systems Limited | Wholesale & retail | 1995 |
| M Jeffries Ltd | Information & communication | 2013 |
| M Liston Groundwork’S Ltd | Construction | 2024 |
| M P Gaskin Plumbing and Heating Ltd | Construction | 2016 |
| M R Krumova Limited | Health & social care | 2009 |
| M S M Carpentry Contractors Limited | Construction | 2002 |
| M&A Services (Hampshire) Ltd | Other services | 2022 |
| M&D Roses Ltd | Wholesale & retail | 2019 |
| M&M Plant Sales Ltd | Wholesale & retail | 2019 |
| M&M Recovery Ltd | Wholesale & retail | 2014 |
| M&Rp Properties Limited | Real estate | 2023 |
| M&T Allen Limited | Administrative & support | 2023 |
| M. Clark Mediation Ltd | Professional & scientific | 2025 |
| M. G. Duff International Limited | Manufacturing | 1991 |
| M. Haines Building & Carpentry Ltd | Construction | 2019 |
| M.G. Duff and Partners Limited | Manufacturing | 1956 |
| M.G.Duff International Holdings Ltd | Financial services | 2023 |
| M.H. Kennedy and SON Limited | Other services | 2002 |
| M.I.P. (Roofing) Limited | Construction | 2003 |
| M.J Howard MDC Limited | Professional & scientific | 2022 |
| M.K.W. Developments Limited | Construction | 1971 |
| M2 Mediapost UK Limited | Information & communication | 2023 |
| M366 Limited | Information & communication | 2021 |
| Maal Group Ltd | Real estate | 2004 |
| MAB Consult, Advisory and Support Limited | Professional & scientific | 2024 |
| Mabelrae Ltd | Wholesale & retail | 2021 |
| Maber Engineering Ltd | Information & communication | 2025 |
| Mach Solutions Ltd | Professional & scientific | 2022 |
| Mack's & Sons Deliveries Limited | Wholesale & retail | 2004 |
| Mackenzie & Ebert Limited | Professional & scientific | 2004 |
| Macks and SON Ltd | Wholesale & retail | 2006 |
| Macks and Sons Flat Pack Ltd | Real estate | 2018 |
| Macks Disposals Ltd | Wholesale & retail | 2007 |
| Mackworth Associates Ltd | Professional & scientific | 2015 |
| Macondo Coffee Ltd | Manufacturing | 2018 |
| Macsis Group Ltd | Hospitality | 2017 |
| MAD Heron Ltd | Information & communication | 2026 |
| MAD LOU Publishing Limited | Information & communication | 2005 |
| MAD Works Ltd | Professional & scientific | 2025 |
| Madeingoa Ltd | Wholesale & retail | 2021 |
| Madgwick Management Limited | Households | 1999 |
| MAE Gallery Limited | Administrative & support | 2004 |
| Maextro Limited | Professional & scientific | 2025 |
| Magic BUS Global | Extraterritorial | 2015 |
| Magic BUS UK | Arts & recreation | 2008 |
| Magical Weddings Ltd | Hospitality | 2022 |
| Magnolia Care Supported Living Ltd | Health & social care | 2025 |
| Magnum Opus Brighton Ltd | Other services | 2019 |
| Maharini Limited | Wholesale & retail | 2015 |
| Mahugu Ashelford Property Investments Ltd | Real estate | 2024 |
| Maison Plus Limited | Real estate | 2019 |
| Majestique Scents Limited | Wholesale & retail | 2026 |
| Make That Grade Ltd | Education | 2026 |
| Makemake Beer Ltd | Manufacturing | 2018 |
| Making Positive Changes Ltd | Extraterritorial | 2008 |
| Making UP Ltd | Information & communication | 2020 |
| Malcolm Baker Consulting Limited | Professional & scientific | 2009 |
| Malkosz Ltd | Hospitality | 2021 |
| Malthouse Monty Limited | Real estate | 2021 |
| MAN at Arms Bitteswell Limited | Hospitality | 2025 |
| Mana Radiology Ltd | Health & social care | 2016 |
| Managing Partners Services Limited | Administrative & support | 2010 |
| Mandalay Limited | Manufacturing | 2002 |
| Manhire Commercial Ltd | Professional & scientific | 2021 |
| Manhood Farmers Cluster Group Limited | Professional & scientific | 2024 |
| Manhood Peninsula Community Interest Company | Real estate | 2019 |
| Manic Mongoose Ltd | Wholesale & retail | 2006 |
| Manifest Ventures Ltd | Education | 2021 |
| Manifest Your Best Ltd | Education | 2020 |
| Manjua | Real estate | 1986 |
| Manna (UK) Ltd | Administrative & support | 2010 |