| KM and GM Ltd | Professional & scientific | 2026 |
| KMA Designz Ltd | Wholesale & retail | 2024 |
| KMH Scaffolding Limited | Construction | 2018 |
| KMM RTM Company Ltd | Households | 2018 |
| Knightsbridge Interior Designs Ltd | Professional & scientific | 2026 |
| Knightsbridge Kitchens Ltd | Wholesale & retail | 2022 |
| Knownother Ltd | Professional & scientific | 2026 |
| Koda Ltd | Professional & scientific | 2016 |
| Kode Concepts Limited | Information & communication | 2008 |
| KOG Properties Limited | Construction | 2024 |
| Komadori Collectables Limited | Wholesale & retail | 2025 |
| Korvo LLP | | 2020 |
| Kozy Limited | Professional & scientific | 2020 |
| KRD Electrical Services Limited | Construction | 2002 |
| Krisar Limited | Manufacturing | 2010 |
| Krymithian Ltd | Information & communication | 2017 |
| KS Conveyancing Limited | Administrative & support | 2025 |
| KS Properties (Essex) Limited | Real estate | 2012 |
| Ktec Services Limited | Construction | 2017 |
| Ktng Investments Ltd | Real estate | 2026 |
| Kuber Housing Ltd | Real estate | 2023 |
| Kunashe Kare Ltd | Other services | 2024 |
| Kure Group Limited | Financial services | 2021 |
| Kure International Limited | Manufacturing | 2021 |
| Kure Limited | Manufacturing | 2018 |
| KURIAN77 Ltd | Health & social care | 2022 |
| KWA Holdings Ltd | Real estate | 2020 |
| Kwan Optom Ltd | Health & social care | 2024 |
| L & L Bates Properties Ltd | Real estate | 2023 |
| L a Photography Limited | Professional & scientific | 2018 |
| L G Hardy and Sons Ltd | Construction | 2015 |
| L Hunter and Co Limited | Professional & scientific | 2018 |
| L J Island Ltd | Information & communication | 2018 |
| L S N Electrical Limited | Construction | 2015 |
| L&L Consultants Limited | Professional & scientific | 2022 |
| L8 Consults Ltd | Construction | 2019 |
| LA Cubanos Limited | Hospitality | 2016 |
| LA Galleria Furniture Limited | Wholesale & retail | 2006 |
| LA Jolie Bulle Ltd | Health & social care | 2023 |
| LA Quinta Ltd | Hospitality | 2002 |
| LAB Lashes Ltd | Other services | 2019 |
| Lainey B’S Ltd | Hospitality | 2022 |
| Lamb & Lamb Insurance Brokers Limited | Financial services | 2016 |
| Lamb Engineering Co. Limited | Manufacturing | 1983 |
| Lambert Manor Ltd | Other services | 2022 |
| Lamtec Ltd | Wholesale & retail | 2018 |
| Land&Searches Ltd | Information & communication | 2025 |
| Landscaping Essex Limited | Construction | 2022 |
| Lane and Mcnamara Ltd | Other services | 2026 |
| Lane One Advisory Ltd | Professional & scientific | 2025 |
| Langdale Equine Ltd | Wholesale & retail | 2008 |
| Laporte Garage Doors Limited | Administrative & support | 2018 |
| Lara Blow Limited | Professional & scientific | 2018 |
| Lara Conveyancing Ltd | Professional & scientific | 2025 |
| Latino Leisure Limited | Hospitality | 2025 |
| Latino's Leisure Limited | Hospitality | 2008 |
| Latitude Clinical Ltd | Professional & scientific | 2026 |
| Lawnside Garden Co. Ltd | Wholesale & retail | 2004 |
| Lawrence Lawrence Ltd | Construction | 2022 |
| Layla's Beauty Limited | Other services | 2013 |
| LB Building Developments Ltd | Construction | 2021 |
| LB Construction Services Ltd | Construction | 2015 |
| LB Consultancy & Installation Services Ltd | Information & communication | 2023 |
| LBP Automotive Limited | Wholesale & retail | 2024 |
| LCB Futures Dmcc Ltd | Financial services | 2022 |
| LD Corporate Entertainment Limited | Hospitality | 2008 |
| LDC Fish & Chips Ltd | Hospitality | 2025 |
| LDH Project Services Ltd | Construction | 2014 |
| LDI Search Ltd | Administrative & support | 2022 |
| LDI Solutions Limited | Administrative & support | 2005 |
| Lead Lash Ltd | Professional & scientific | 2025 |
| Leap Pathways CIC | Education | 2025 |
| Ledhar Property Group Limited | Real estate | 2020 |
| LEE DRY Lining Limited | Construction | 2015 |
| Leggett Driving Services Limited | Transport & logistics | 2013 |
| Legit Logic Ltd | Information & communication | 2024 |
| Legon Consulting Ltd | Professional & scientific | 2019 |
| Leigh Flooring Limited | Construction | 2026 |
| Leigh Park Court Limited | Households | 1997 |
| Leigh Planning Services Limited | Information & communication | 2009 |
| Letlux Property Services Ltd | Hospitality | 2025 |
| Lets Talk and Communicate Ltd | Education | 2014 |
| Letter Studio Ltd | Professional & scientific | 2024 |
| Lewis Education Consultancy Limited | Education | 2015 |
| Lewislimani Ltd | Real estate | 2023 |
| LEX Accountancy Limited | Professional & scientific | 1998 |
| Lexx Chimney Services & Fire Safety Limited | Transport & logistics | 2023 |
| Leytonstone Worktops Limited | Construction | 2018 |
| LF Consultancy Limited | Wholesale & retail | 2026 |
| LG Physiotherapy, Ultrasound & Injection Clinic Ltd | Other services | 2024 |
| LGA Finishing Limited | Manufacturing | 2010 |
| LGB Supplies Ltd | Construction | 2025 |
| LH Clinical Ltd | Health & social care | 2018 |
| LHM GAS Services Limited | Energy | 2023 |
| Libertax Ltd | Professional & scientific | 2020 |
| Libratum Limited | Health & social care | 2011 |
| Lifco Properties Limited | Real estate | 1998 |
| Life & Direct Ltd | Financial services | 2026 |
| Liftrite Ltd | Professional & scientific | 2025 |
| Light of Life Chapel International Ltd | Other services | 2022 |