| JMI Consultancy Ltd | Professional & scientific | 2026 |
| Josh Mann Consulting Limited | Information & communication | 2017 |
| JPG Fibre Consultancy Ltd | Professional & scientific | 2020 |
| JRB Renovations Ltd | Real estate | 2017 |
| Judge Security Ltd | Administrative & support | 2025 |
| JUT Property Ltd | Construction | 2026 |
| K C Edwards (Builders) Limited | Construction | 2001 |
| K Harvey Consultancy Ltd | Information & communication | 2016 |
| K.J. Beales Limited | Construction | 2003 |
| Kayne IS Able Limited | Information & communication | 2012 |
| KB Groundworks Ltd | Construction | 2024 |
| Keane’S Property Developments Limited | Construction | 2025 |
| Keele Ltd | Transport & logistics | 2020 |
| Kemball & Franklyn Ltd | Wholesale & retail | 2022 |
| Kempire Properties Ltd | Real estate | 2017 |
| Kennelly Mccarthy Construction Services Ltd | Professional & scientific | 2025 |
| Kennelly Mccarthy Group Ltd | Financial services | 2026 |
| Kensington Place (NR1) Ltd | Households | 2022 |
| Kent Holdco Ltd | Financial services | 2023 |
| Kevellens Limited | Transport & logistics | 2016 |
| Kiki James Ltd | Manufacturing | 2025 |
| KJM Consulting Limited | Professional & scientific | 2023 |
| Knox Site Solutions Ltd | Construction | 2016 |
| L & C Rental Limited | Real estate | 2019 |
| L & J Projects Limited | Construction | 1996 |
| L & R Traffic Management Ltd | Construction | 2019 |
| L a Shaw Building Contractor Limited | Construction | 1995 |
| L&A Carpentry Partners Ltd | Construction | 2022 |
| L. Nightingale Ltd | Education | 2012 |
| L.W.Commissions Limited | Information & communication | 1994 |
| Laffak Ltd | Wholesale & retail | 2009 |
| Lamech Lifts Ltd | Manufacturing | 2019 |
| Landlordsync Ltd | Information & communication | 2025 |
| Laulou TCG Limited | Wholesale & retail | 2025 |
| Lavish (Norfolk) Ltd | Other services | 2022 |
| LC Training and Consultancy Ltd | Other services | 2017 |
| LCH Building & Maintenance Ltd | Construction | 2024 |
| LEE & Plumpton Limited | Manufacturing | 1975 |
| LEE Steel Solutions Limited | Construction | 2015 |
| Leonards Pigs Limited | Agriculture & fishing | 2016 |
| LEY Brickwork Ltd | Construction | 2018 |
| Leyria Limited | Professional & scientific | 2014 |
| LH Groundworks Limited | Construction | 2017 |
| Lisatrode Services Limited | Construction | 1998 |
| Little Acorn Nursery Norfolk Ltd | Health & social care | 2026 |
| Little Boutique Ltd | Wholesale & retail | 2019 |
| LJB Fire Safety + Limited | Public administration | 2016 |
| LJX Services Ltd | Wholesale & retail | 2022 |
| LL Pet Services Ltd | Other services | 2026 |
| LMH Flooring Limited | Construction | 2017 |
| Lodge Farm Recycling Ltd | Construction | 2016 |
| Logun Investments Limited | Real estate | 2009 |
| Lohan Property Limited | Real estate | 2019 |
| Loose Leaf Marketing Ltd | Professional & scientific | 2025 |
| Lotus Psychology Ltd | Health & social care | 2017 |
| Louise MAY Aesthetics Ltd | Health & social care | 2025 |
| Louise Wilding Limited | Hospitality | 2025 |
| Loving by Giving Ltd | Health & social care | 2011 |
| Loxter Properties Ltd | Real estate | 2025 |
| LS FBA Ltd | Wholesale & retail | 2025 |
| LT Management Services Limited | Real estate | 1987 |
| LT PUB Management PLC | Professional & scientific | 2010 |
| LT PUB Support Services Limited | Professional & scientific | 2010 |
| LTM NO.1 Limited | Wholesale & retail | 2010 |
| Luckhurst Holdings Limited | Financial services | 2019 |
| Lukas Regulatory Solutions Ltd | Professional & scientific | 2025 |
| Luke Bell HE Solutions Ltd | Information & communication | 2022 |
| Lumetrix Energy Limited | Energy | 2025 |
| Luminaro Properties Ltd | Financial services | 2025 |
| Lust for Life Productions Ltd | Information & communication | 2024 |
| Luxury Outdoor Design Ltd | Manufacturing | 2023 |
| Lwleatherworking Ltd | Wholesale & retail | 2025 |
| Lyng Property Management Limited | Administrative & support | 2005 |
| M & a Norfolk Holdings Ltd | Financial services | 2021 |
| M & a Norfolk Investments Ltd | Real estate | 2021 |
| M & a Norfolk Ltd | Construction | 2018 |
| M & C Bunney Ltd | Professional & scientific | 2026 |
| M & J B Associates Limited | Professional & scientific | 1994 |
| M Brothers Catering Ltd | Hospitality | 2026 |
| M C Business Services Limited | Administrative & support | 2007 |
| M G Farms Limited | Agriculture & fishing | 2021 |
| MAB Contracting CS Ltd | Construction | 2023 |
| MAB Plant Hire Ltd | Administrative & support | 2023 |
| Macbrook Construction Ltd | Real estate | 2020 |
| Macbrookgas Ltd | Construction | 2016 |
| Made by Regina Limited | Hospitality | 2022 |
| Magpie Metal Detectors Ltd | Wholesale & retail | 2024 |
| MAID2CLEAN Norwich Ltd | Administrative & support | 2011 |
| Maidplace Limited | Professional & scientific | 1996 |
| Managed Plant Services Ltd | Professional & scientific | 2019 |
| Mandalay Opco Limited | Hospitality | 2023 |
| Maple Barns Grooming Ltd | Other services | 2023 |
| MAPP3D Ltd | Professional & scientific | 2025 |
| Mardy Media Limited | Information & communication | 2003 |
| Maresco Limited | Construction | 1970 |
| Marriott Maintenance Ltd | Construction | 2023 |
| MAS Consultants (London) Ltd | Real estate | 2004 |
| Mattcan Limited | Professional & scientific | 2020 |
| Maxmila Group Ltd | Information & communication | 2025 |
| Maze HR Consulting Ltd | Administrative & support | 2024 |