| KPS Consulting Limited | Professional & scientific | 2021 |
| Kraido Ltd | Wholesale & retail | 2019 |
| KSD Production Services Limited | Administrative & support | 2026 |
| KTS Shana Limited | Wholesale & retail | 2024 |
| Kukuki-Transport Ltd | Transport & logistics | 2021 |
| Kyber Automation Ltd | Information & communication | 2025 |
| L a Custom Coatings Ltd | Other services | 2022 |
| L & J Decorating Services Ltd | Construction | 2021 |
| L L Landscaping and Tree Services Ltd | Professional & scientific | 2025 |
| L.F.S. Property Group Limited | Real estate | 2015 |
| Lacco Ltd | Hospitality | 2024 |
| Laingchild Investments Limited | Real estate | 2025 |
| Lakeland Solutions Ltd | Real estate | 2010 |
| Lappin Group Ltd | Construction | 2019 |
| Largos Property Ltd | Real estate | 2023 |
| Larks Place Management Company Limited | Households | 2007 |
| Lashings Ltd | Manufacturing | 2018 |
| Laura Shaw Financial Holdings Limited | Financial services | 2024 |
| Laura Shaw Financial Planning Limited | Financial services | 2020 |
| Lawrences Garages (London) Limited | Wholesale & retail | 1957 |
| Laws Services Limited | Real estate | 2021 |
| Lazenby Pyper Limited | Wholesale & retail | 2013 |
| LB Fusion Limited | Wholesale & retail | 2019 |
| LDW Frosdick Contracting Ltd | Administrative & support | 2024 |
| Leach O'Connell Consultancy Ltd | Professional & scientific | 2017 |
| Leadify Holdings Ltd | Administrative & support | 2024 |
| Leaf Recruitment Services Ltd | Administrative & support | 2016 |
| LEC Camh Consulting Ltd | Health & social care | 2021 |
| Leeder Accident Repair Centre Limited | Wholesale & retail | 2001 |
| Legends Afoot Limited | Information & communication | 2024 |
| Lemuria Holdings Ltd | Professional & scientific | 2026 |
| Letton Architectural Design Limited | Professional & scientific | 2024 |
| Level UP Gaming Cafe Limited | Hospitality | 2019 |
| Level UP Virtual Limited | Administrative & support | 2021 |
| LG Construction Supplies Limited | Wholesale & retail | 2026 |
| LG Designs Limited | Professional & scientific | 2003 |
| LGL Energy Holdings Limited | Financial services | 2025 |
| LGL Energy Ltd | Financial services | 2013 |
| Lifetime Pathway Ltd | Professional & scientific | 2014 |
| Lifetime Racing Limited | Professional & scientific | 2018 |
| Lightwork Ecommerce Limited | Information & communication | 2026 |
| Lily Impact Ltd | Professional & scientific | 2025 |
| Limahbakeandfoodshop Ltd | Manufacturing | 2026 |
| Lincoln House Care Home Ltd | Health & social care | 2002 |
| Lites Construction Ltd | Construction | 2019 |
| Little Footsteps of Dereham Ltd | Education | 2011 |
| Little Footsteps of Mattishall Limited | Health & social care | 2018 |
| Little White Lamb Co Ltd. | Agriculture & fishing | 2017 |
| Living-Space (East Anglia) Ltd | Administrative & support | 2020 |
| LK Amira Limited | Hospitality | 2026 |
| LL Motor Services Limited | Wholesale & retail | 2023 |
| Lloyd Bowles Limited | Construction | 2016 |
| Lloyds Training Associates Ltd | Professional & scientific | 2013 |
| LNS Interiors Limited | Construction | 2019 |
| Locket Management Ltd | Real estate | 2015 |
| Lodge Farm Holdings Ltd | Real estate | 2020 |
| Logic Red Web Design Limited | Information & communication | 2013 |
| Longman Services Ltd | Construction | 2015 |
| Love at First Bite Norfolk Ltd | Hospitality | 2026 |
| Love Tile and Stone Limited | Construction | 2025 |
| LOW Farm East Ltd | Professional & scientific | 2016 |
| Lrsc Limited | Professional & scientific | 2019 |
| LTM Publishing Limited | Information & communication | 2004 |
| Ludkin & SON Ltd. | Real estate | 1998 |
| Lynn Road Garage Limited | Wholesale & retail | 2023 |
| Lynx Educational Trust for Animal Welfare Limited | Health & social care | 1987 |
| M & D Farms Ltd | Agriculture & fishing | 2013 |
| M & J Coughlan Limited | Hospitality | 2010 |
| M & M Commercials Ltd | Wholesale & retail | 2026 |
| M H Tractors Limited | Wholesale & retail | 2019 |
| M J & J a Howard & SON Limited | Wholesale & retail | 2007 |
| M K Warehousing Ltd | Wholesale & retail | 2003 |
| M Parker Limited | Information & communication | 2007 |
| M R Groundworks Limited | Construction | 2016 |
| M&S Wealth Ltd | Real estate | 2025 |
| M. R Cooling Ltd | Energy | 2025 |
| M.A.R. (Builders) Limited | Construction | 1975 |
| M.J.B. Builders Ltd | Construction | 2004 |
| M.T. Anderton and Associates Limited | Construction | 1986 |
| MA Autocool Limited | Wholesale & retail | 2002 |
| Macadam Ltd | Other services | 2017 |
| Macadam SE Ltd | Construction | 2021 |
| Mackley Enterprises Ltd | Real estate | 2024 |
| Mackley IT Limited | Information & communication | 2018 |
| Mackley Property Holdings Ltd | Real estate | 2026 |
| Magical Events Limited | Wholesale & retail | 2013 |
| Mahao Company Limited | Health & social care | 2023 |
| Maia EDA Ltd | Information & communication | 2020 |
| Majestic Events (Kent) Limited | Other services | 2010 |
| MAK Personnel Holdings Ltd | Financial services | 2023 |
| MAK Personnel Limited | Administrative & support | 2012 |
| MAM Industrial LLP | | 2019 |
| Mansom's Grove Limited | Construction | 2015 |
| Manu MEA Ltd | Wholesale & retail | 2021 |
| Maple Cone Limited | Professional & scientific | 2016 |
| Maple Tree Care (Dereham) Limited | Health & social care | 2022 |
| Maple Tree Care Limited | Health & social care | 2012 |
| Maple Tree Group Limited | Financial services | 2024 |
| Maple Tree Holdings Ltd | Health & social care | 2023 |
| Marchant Read & Husk MRH Limited | Administrative & support | 2025 |