| KE Communications Limited | Extraterritorial | 2015 |
| Keen & Betts Limited | Wholesale & retail | 1971 |
| Kenja Consulting Limited | Professional & scientific | 2015 |
| Kingswood at Home Limited | Construction | 2015 |
| Knight Plumbing and Heating Ltd | Construction | 2017 |
| Knox Motor Sports Limited | Arts & recreation | 2024 |
| Kollibri Ltd | Manufacturing | 2025 |
| KT Nails Henfield Limited | Other services | 2022 |
| L Prentice Art and Antiques Ltd | Wholesale & retail | 2016 |
| Laing Fine Art Ltd | Arts & recreation | 2009 |
| Lance Cronin Football Academy Ltd | Education | 2024 |
| Land & Power Electrical Contracting Limited | Construction | 2015 |
| Land and Power Limited | Construction | 2013 |
| Lanehurst Consulting Limited | Information & communication | 2006 |
| Lanmar Electrical Limited | Construction | 2010 |
| Lean Family Group Limited | Construction | 2023 |
| LEX Lettings Limited | Real estate | 2015 |
| LEX Property Holdings Ltd | Real estate | 2024 |
| LEX Property Management Limited | Real estate | 2024 |
| LEX Property Services Limited | Real estate | 2018 |
| Liam Jackson Limited | Construction | 2016 |
| Life Global Holdings Limited | Extraterritorial | 2006 |
| Life UK Limited | Wholesale & retail | 2006 |
| Lindsey 21 Limited | Other services | 2026 |
| Liquidamber Tree Surgery Ltd | Agriculture & fishing | 2022 |
| Liquidamber Tree Surveys Ltd | Professional & scientific | 2023 |
| Littluns Ltd | Professional & scientific | 2024 |
| LIVE4LAPLAND Limited | Hospitality | 2022 |
| Lloyd Gofton Ltd | Professional & scientific | 2006 |
| Loader Management Services Limited | Professional & scientific | 2012 |
| Logan Advisory Services Ltd | Professional & scientific | 2025 |
| Loudcity.Tv Ltd | Administrative & support | 2014 |
| Love Property Management (Sussex) Ltd | Construction | 2025 |
| LTW Investments Ltd | Construction | 2023 |
| Luke & Luke Construction Limited | Construction | 2003 |
| Lynettski Limited | Hospitality | 2021 |
| M J Property Sussex Ltd | Real estate | 2013 |
| M Weeks Construction & Renovations Limited | Construction | 2010 |
| M.L Paine's Window Cleaning Limited | Administrative & support | 2011 |
| MAD Jack Design House Ltd | Wholesale & retail | 2023 |
| Magraserley Ltd | Wholesale & retail | 2022 |
| Maikai Limited | Wholesale & retail | 2010 |
| Majahma Ltd | Manufacturing | 2024 |
| Manning of Fishponds Limited | Real estate | 1972 |
| Manton Business Consulting Limited | Professional & scientific | 2018 |
| Markexport Sussex Ltd | Professional & scientific | 2014 |
| Martello Risk Limited | Administrative & support | 2010 |
| Martin LEE Design Limited | Administrative & support | 2013 |
| Martingales (Sayers Common) Management Limited | Households | 2003 |
| Masc Limited | Professional & scientific | 1984 |
| Massena Services Ltd | Real estate | 2003 |
| Matt Owen GAS & Heating Services Limited | Construction | 2018 |
| MAW Solutions Limited | Wholesale & retail | 2001 |
| Maydean Electrical & Mechanical Engineers Ltd | Construction | 2020 |
| Maydean Limited | Construction | 2009 |
| Mcrd Parsons Holdings Limited | Extraterritorial | 2025 |
| Meacham & Mann Ltd | Construction | 2017 |
| Mega Events Limited | Administrative & support | 2012 |
| Meliora Opulentos Ltd | Financial services | 2022 |
| Michael Finn & Company Limited | Professional & scientific | 2003 |
| Michael Modlock Ltd | Construction | 2015 |
| Micheal Distribution Ltd | Construction | 2024 |
| Middle Ground Dispute Solutions Limited | Administrative & support | 2023 |
| Middlemark Consultancy Limited | Professional & scientific | 2013 |
| Miki Property Development Limited | Real estate | 2024 |
| Mile Oak Services Ltd | Wholesale & retail | 2013 |
| Millbrook Workshop Units Ltd | Real estate | 2013 |
| Millen Griffiths Investment Consultants Limited | Professional & scientific | 2002 |
| Mindset and Glow Ltd | Administrative & support | 2019 |
| MJG Construction & Development Limited | Construction | 2010 |
| MLW Consulting Limited | Professional & scientific | 2018 |
| MNN Maintenance Ltd | Administrative & support | 2023 |
| Morecote Limited | Administrative & support | 2013 |
| Moving Mountains Snowsports Limited | Arts & recreation | 2017 |
| MPI Developers Ltd | Construction | 2023 |
| MS Garrod Limited | Wholesale & retail | 2019 |
| Muse Medical Communications Ltd | Professional & scientific | 2021 |
| Mvee Limited | Professional & scientific | 2009 |
| MW Electrical Engineering Ltd | Construction | 2023 |
| My Deeside Surgery Solutions Ltd | Professional & scientific | 2023 |
| My Dog Supplies Limited | Wholesale & retail | 2017 |
| N Seal Limited | Construction | 2009 |
| Nailed IT Property Ltd | Construction | 2025 |
| Nanowise Ltd | Information & communication | 2024 |
| National Community Wood Recycling Project | Water & waste | 2003 |
| Naturally Cyber LLP | | 2019 |
| Neaves Estates Limited | Professional & scientific | 2009 |
| New Generation Electrical Southern Ltd | Construction | 2013 |
| New MED Healthcare Solutions Ltd | Extraterritorial | 2014 |
| NEW23 Limited | Construction | 2020 |
| NGS Wheatsheaf Ltd | Hospitality | 2024 |
| NH Universal Ltd | Wholesale & retail | 2017 |
| Nick Platt Services Limited | Administrative & support | 2009 |
| Northumberland 21 Limited | Construction | 2026 |
| Norvic Aero Engines Limited | Manufacturing | 1995 |
| Offset Bushings Limited | Manufacturing | 2017 |
| Ogilvie Design Studio Ltd | Administrative & support | 2013 |
| Okcular Limited | Hospitality | 2025 |
| Old London House Limited | Hospitality | 2022 |
| Oliver Gillard (Southmead) Limited | Real estate | 1965 |