| LJW (West Sussex) Limited | Extraterritorial | 2018 |
| LK Warren Property Limited | Real estate | 2017 |
| Lksc Ltd | Information & communication | 2018 |
| LL Prestige Property Solutions Ltd | Professional & scientific | 2019 |
| LLM Medics Ltd | Health & social care | 2025 |
| Lloyd Carpets Limited | Wholesale & retail | 2005 |
| Lloyd Peek Design Limited | Professional & scientific | 2018 |
| LLR Cleaning Services Ltd | Administrative & support | 2026 |
| LM Bespoke Wardrobes Limited | Manufacturing | 2020 |
| LMA Payroll Limited | Professional & scientific | 2012 |
| Lmwr Properties Ltd | Hospitality | 2025 |
| Location Security Limited | Administrative & support | 2018 |
| Lock UP Garages and Property Maintenance Limited | Administrative & support | 2016 |
| Lockdown Shutters Limited | Construction | 2014 |
| Lockhart Electrical Limited | Construction | 2013 |
| Locosoco Group PLC | Financial services | 2016 |
| Locosoco Limited | Information & communication | 2014 |
| Locum & Consultancy Services Ltd | Professional & scientific | 2018 |
| Locutio Voice Technologies Ltd | Information & communication | 2004 |
| Logic Brickwork Limited | Construction | 2024 |
| Logic Sprinkler Fire Protection LLP | | 2009 |
| Logicode Technologies Ltd | Information & communication | 2026 |
| Logicsticks Information Technology Ltd | Information & communication | 2004 |
| Logistics XOP Ltd | Transport & logistics | 2021 |
| Logos Legal Services Limited | Administrative & support | 2006 |
| London & Home Counties Tiling Contractors Limited | Construction | 2007 |
| London Basements and Waterproofing Ltd | Construction | 2025 |
| London Commod Limited | Financial services | 2023 |
| London Insulation Services Ltd | Construction | 2018 |
| London PM Ltd | Real estate | 2021 |
| London Road (Block a) Management Company Limited | Households | 1991 |
| London Road (Block L) Management Company Limited | Households | 1991 |
| London Road (Essex) Ltd | Construction | 2024 |
| London Road UK Valeting Ltd | Wholesale & retail | 2015 |
| London Shoeshine Limited | Other services | 2011 |
| London Steel Services Ltd | Manufacturing | 2018 |
| London Structures (UK) Ltd | Construction | 2022 |
| Londonco Cleaning Ltd | Administrative & support | 2024 |
| Longtail Tech Ltd | Information & communication | 2023 |
| Longwoodey Limited | Administrative & support | 1999 |
| Look Services Ltd | Water & waste | 2022 |
| Lord Home Refurb Ltd | Construction | 2024 |
| Lords of London Ltd | Financial services | 2024 |
| Lorenzo Clothing Limited | Wholesale & retail | 2017 |
| Lorraine Pastry Co Limited | Hospitality | 2024 |
| LOS Box Clothing Ltd | Wholesale & retail | 2025 |
| LOS Coating Ltd | Construction | 2026 |
| LOS Group Limited | Professional & scientific | 2023 |
| LOS Pasta Co Limited | Hospitality | 2026 |
| LOS Property Investments Ltd | Real estate | 2020 |
| Loserville Limited | Information & communication | 2012 |
| Louclem Properties Ltd | Real estate | 2024 |
| Loudmouth Snacks Ltd | Manufacturing | 2019 |
| Louise Perry Weddings & Events Limited | Information & communication | 2003 |
| Love Sustained Bridal Studio Ltd | Wholesale & retail | 2019 |
| Love-Leigh Teepees Ltd | Administrative & support | 2020 |
| Loveproducts Ltd | Administrative & support | 2020 |
| Lovibond Holdings Ltd | Financial services | 2024 |
| LOW Carbon Display Limited | Information & communication | 2019 |
| Lowe Project Management Consultancy Limited | Information & communication | 2025 |
| LR Boxing Ltd | Arts & recreation | 2025 |
| LRC Building Services Limited | Construction | 2014 |
| LS Civil Engineering Essex Ltd | Construction | 2025 |
| LSJ News Ltd | Wholesale & retail | 2024 |
| LSR Traders Ltd | Wholesale & retail | 2020 |
| LTK Scott Limited | Administrative & support | 2007 |
| Lucas Media Group Ltd | Professional & scientific | 2024 |
| Lucky Cat Ventures Limited | Information & communication | 2025 |
| Lucy Gray Limited | Health & social care | 2017 |
| Lucy Jackson Limited | Other services | 2022 |
| Luke Adam Hawker Ltd | Arts & recreation | 2023 |
| Luke Barnes Holdings Limited | Financial services | 2022 |
| Luke Buckley Rail Limited | Professional & scientific | 2017 |
| Luke W Electrical Ltd | Construction | 2021 |
| Lumeria Ltd | Information & communication | 2023 |
| Luna's Boutique 28 Limited | Wholesale & retail | 2019 |
| Luneburg Limited | Professional & scientific | 2014 |
| Luton Steels Limited | Administrative & support | 1998 |
| LUX Development Partners Limited | Professional & scientific | 2025 |
| Luxatti Ventures Ltd | Construction | 2022 |
| Luxe Mobility Limited | Wholesale & retail | 2024 |
| Luxe Pets Ltd | Other services | 2022 |
| Luxlovesdogs Ltd | Other services | 2024 |
| Luxurious Time Limited | Wholesale & retail | 2025 |
| Luxury Country Stays Limited | Real estate | 2022 |
| Luxury Golf Co. Ltd | Wholesale & retail | 2026 |
| Luxx Lifestyle Ltd | Hospitality | 2019 |
| LX TEC Limited | Professional & scientific | 2019 |
| LXF Limited | Professional & scientific | 2023 |
| Lycia Limited | Wholesale & retail | 2002 |
| Lycia Residential Limited | Real estate | 2021 |
| Lydia Siniak Limited | Health & social care | 2011 |
| Lydon Project Ltd | Administrative & support | 2023 |
| Lygoe Creative Ltd | Information & communication | 2013 |
| Lynch Decorating Services Limited | Construction | 2023 |
| Lyons Apartments Ltd | Real estate | 2018 |
| Lyons Young Limited | Construction | 2017 |
| LZB Futures Ltd | Financial services | 2012 |
| LZM and Co Ltd | Real estate | 2012 |
| L’Unico Essex Ristorante Ltd | Hospitality | 2023 |