| Kinfolk Therapy Ltd | Health & social care | 2022 |
| Kingdom & Company Surveyors LLP | | 2020 |
| Kings Carpets Ltd | Wholesale & retail | 2020 |
| Kingsland Farm Services LLP | | 2012 |
| Kiota Home Ltd | Wholesale & retail | 2024 |
| Kirkham Properties Ltd | Construction | 2016 |
| Kirkhams Investments Limited | Real estate | 2017 |
| Kitten Kartel Limited | Manufacturing | 2025 |
| Kjbyford Ltd | Other services | 2022 |
| KJE Limited | Professional & scientific | 2004 |
| KJY Solutions Ltd | Information & communication | 2025 |
| KMP Construction Limited | Construction | 2016 |
| Knight Farming Limited | Agriculture & fishing | 2012 |
| Knights Car and Van Sales Limited | Wholesale & retail | 2020 |
| Kolson Limited | Wholesale & retail | 2014 |
| Koru Liquor Brands Sourcing Ltd | Other services | 2019 |
| Koutoubia Limited | Information & communication | 2022 |
| KPN Electrical Limited | Construction | 2006 |
| KSW Property Holdings Limited | Real estate | 2026 |
| Kyrie Russell Limited | Financial services | 2021 |
| L C Groundworks Ltd | Construction | 2024 |
| L G F Financials Limited | Financial services | 2008 |
| L&V's Bark 'N Bake Ltd | Manufacturing | 2025 |
| Ladles & Jellyspoons (Hair Boutique) Ltd. | Other services | 2015 |
| Land and Boundary Limited | Administrative & support | 2025 |
| Langdons Antiques and Collectibles Ltd | Wholesale & retail | 2026 |
| Langthorns Plantery Limited | Agriculture & fishing | 2018 |
| Larmour Developments & Co Ltd. | Professional & scientific | 1993 |
| Laser Interiors (UK) Limited | Construction | 2013 |
| Latchford Construction Services Limited | Construction | 2010 |
| Latona Bishops Stortford Ltd | Education | 2025 |
| Latona Global Holdings Limited | Professional & scientific | 2025 |
| Latona Saffron Walden Ltd | Education | 2025 |
| Latona Sawbridgeworth Ltd | Education | 2025 |
| Lauren Pinchbeck Childcare Ltd | Education | 2026 |
| Leaden Hall Farm Barns Management Company Limited | Real estate | 2012 |
| Leak Detection Europe Limited | Construction | 2014 |
| Learning@Leeds Ltd | Professional & scientific | 2016 |
| Lebanese Gourmet (Essex) Limited | Hospitality | 2023 |
| Leemelly Investments Ltd | Real estate | 2017 |
| Leep Executive (PA) Limited | Real estate | 2013 |
| Legacy Tattoo Studio Ltd | Other services | 2021 |
| Legacy TCG Ltd | Wholesale & retail | 2025 |
| Let's Design This Ltd | Professional & scientific | 2021 |
| Let's Talk SLT Ltd | Education | 2014 |
| Lfash Solutions Limited | Health & social care | 2011 |
| Lifesafety Limited | Public administration | 2005 |
| Lifestyle Creative Developments Limited | Construction | 2006 |
| Light Foods Ltd | Manufacturing | 2025 |
| Lighten Property Solutions Ltd | Real estate | 2017 |
| Lindridge Limited | Professional & scientific | 2015 |
| Line and Point Limited | Information & communication | 2016 |
| Linermist Limited | Professional & scientific | 2020 |
| Listeco Limited | Construction | 2024 |
| Little Blossom Farm Ltd | Agriculture & fishing | 2011 |
| Little Monsters House of FUN Ltd | Arts & recreation | 2014 |
| Littleroc Ltd | Professional & scientific | 2019 |
| Livewire Holdings Limited | Professional & scientific | 2018 |
| Livewire Legacy Ltd | Professional & scientific | 2021 |
| Living Streams Ministries | Other services | 2003 |
| Lixen Interiors Ltd | Construction | 2024 |
| Lixen Ltd | Professional & scientific | 2022 |
| LJL Training Limited | Professional & scientific | 2022 |
| LK Developments Limited | Construction | 2002 |
| LK Enterprises Limited | Professional & scientific | 2018 |
| LK General Services Ltd | Construction | 2024 |
| LL Walser Construction Limited | Construction | 2025 |
| Lmc-Uk Limited | Administrative & support | 1999 |
| Local Food (& More!) Co-Operative Ltd | Hospitality | 2012 |
| Lock Equestrian Ltd | Agriculture & fishing | 2026 |
| Lodge Coaching Solutions Limited | Health & social care | 2025 |
| London 2 Airports Chauffeur Ltd | Transport & logistics | 2018 |
| London Office Clearance Limited | Transport & logistics | 2024 |
| London Stansted Chauffeurs Limited | Transport & logistics | 2015 |
| London Stansted Coaches Limited | Transport & logistics | 2024 |
| London Stansted Commercial Cleaning Limited | Administrative & support | 2024 |
| London Stansted Commercials Limited | Water & waste | 2024 |
| London Village Inns Limited | Professional & scientific | 2012 |
| Lonesome Jubilee Limited | Professional & scientific | 2014 |
| Look Sharp Grooming Ltd | Other services | 2024 |
| Lorelle Rayner Ltd | Other services | 2015 |
| Lottica Event Management Ltd | Professional & scientific | 2018 |
| Loud Kitchen Ltd | Manufacturing | 2026 |
| Louise Richardson Limited | Professional & scientific | 2007 |
| Love Lilly Limited | Administrative & support | 2018 |
| Lshi Consulting Ltd | Professional & scientific | 2014 |
| LSP Property Limited | Hospitality | 2019 |
| Luckin Designs Ltd | Professional & scientific | 2020 |
| Lucky INK Limited | Manufacturing | 2023 |
| Luminary Resonance Ltd | Education | 2023 |
| Luna Law Limited | Professional & scientific | 2019 |
| Lunar Film Productions Limited | Information & communication | 2022 |
| Lussolux Travel Limited | Transport & logistics | 2026 |
| Luux Landscapes Limited | Administrative & support | 2020 |
| Luux Tree Surgery Limited | Administrative & support | 2018 |
| LYN Warner & Associates Ltd | Professional & scientific | 2000 |
| Lynch Building Services Limited | Construction | 2013 |
| M & B Printers Limited | Manufacturing | 2013 |
| M Boyes Properties Limited | Real estate | 2003 |
| M D English Telecoms Ltd | Information & communication | 2025 |