| LJ and Sons Limited | Other services | 2022 |
| LJB Building and Construction Ltd | Construction | 2024 |
| LJB Consultancy Services Ltd | Administrative & support | 2016 |
| LJH Clinical Systems Consultancy Ltd | Information & communication | 2022 |
| LJL Plastering Drylining and Floor Screeds Limited | Construction | 2013 |
| LJR Assessments Ltd | Professional & scientific | 2022 |
| LJS Content Ltd | Professional & scientific | 2019 |
| LJS Developments Limited | Construction | 2017 |
| LJW Sourcing Ltd | Professional & scientific | 2025 |
| Ljwpt Limited | Health & social care | 2025 |
| LMS First Limited | Professional & scientific | 2021 |
| Loakewood Lettings Ltd | Real estate | 2024 |
| Location Strategy Management Limited | Professional & scientific | 2016 |
| Lock and Key Mortgages Ltd | Financial services | 2023 |
| Lockfit(Southampton) Ltd | Other services | 2020 |
| Locumotion Ltd | Health & social care | 2010 |
| Lodahl Aero Ltd | Manufacturing | 2011 |
| Lodge & Keep Construction Ltd | Construction | 2018 |
| Logic Wireless Europe Limited | Wholesale & retail | 2016 |
| Logistics Employment Training Services Limited | Professional & scientific | 2023 |
| Logistics SOS Limited | Transport & logistics | 2023 |
| London Aesthetic Medicine Academy Ltd | Extraterritorial | 2016 |
| London Aesthetic Medicine Clinic Ltd | Extraterritorial | 2016 |
| London Aesthetic Medicine Ltd | Health & social care | 2013 |
| London Contemporary Art Limited | Wholesale & retail | 2010 |
| London Podcast Studios Ltd | Information & communication | 2024 |
| London Quality SQL Ltd. | Information & communication | 2011 |
| Longmore Estates Management Ltd | Administrative & support | 2021 |
| Longparish Rural Enterprises Limited | Arts & recreation | 2012 |
| Lonmer Construction Limited | Construction | 2013 |
| Loopin Systems Ltd | Administrative & support | 2025 |
| Lopen Care Agency Ltd | Administrative & support | 2021 |
| Lords Oak Haulage Ltd | Transport & logistics | 2022 |
| Lorien Developments Ltd | Construction | 2024 |
| Lorne Sainsbury Builder Ltd | Construction | 2026 |
| Lothbrook Boxers Ltd | Construction | 2021 |
| Lotus Advanced Skincare & Beauty Limited | Other services | 2022 |
| Lotus House (Xinglong) Ltd | Hospitality | 2025 |
| Loula Barbers (Fair Oak) Limited | Other services | 2024 |
| Loula Barbers (Stubbington) Limited | Other services | 2025 |
| Loula Barbers Limited | Other services | 2022 |
| Louskos Limited | Health & social care | 2013 |
| Lovable Technologies Ltd | Information & communication | 2018 |
| Love Your Car Limited | Wholesale & retail | 2024 |
| Lovett Property Investments Ltd | Real estate | 2018 |
| Loving Service Limited | Health & social care | 2025 |
| Loviva Limited | Financial services | 2022 |
| LP Environmental Ltd | Administrative & support | 2023 |
| LPR Carpentry Ltd | Construction | 2021 |
| LRB Creative Ltd | Professional & scientific | 2025 |
| LSC Building Services Holding Limited | Professional & scientific | 2012 |
| LSC Building Services Limited | Construction | 2004 |
| LSC Electrical Limited | Construction | 2005 |
| Lshd Realisations 2023 Limited | Manufacturing | 2006 |
| LSM Project Management Ltd | Professional & scientific | 2023 |
| LST Partnership LLP | | 2012 |
| LST Projects Limited | Extraterritorial | 2017 |
| Luca Composites Limited | Manufacturing | 2018 |
| Lucas Andrew Management Ltd | Administrative & support | 2022 |
| Luci Morgan Estate Agency Ltd | Real estate | 2021 |
| Lucid Brand Delivery Limited | Manufacturing | 2017 |
| Lucky Entertainment 2021 Ltd | Administrative & support | 2021 |
| Lucky Lock Master Ltd | Manufacturing | 2025 |
| Luhv Drinks Limited | Manufacturing | 2015 |
| Luhv Group Limited | Financial services | 2020 |
| Lullula Ecology Limited | Agriculture & fishing | 2024 |
| Lumari Ltd | Other services | 2018 |
| Lundy Bay Property Ltd | Construction | 2021 |
| Lustrum Limited | Information & communication | 2023 |
| Luxion Group Limited | Information & communication | 2003 |
| Luxion Holdings Limited | Financial services | 2023 |
| Luxion Renewables Limited | Energy | 2024 |
| LVC Ventures Limited | Professional & scientific | 2024 |
| LVS Engineering Limited | Construction | 2014 |
| LW Fire Systems Limited | Administrative & support | 2025 |
| LXG Health Initiative Ltd | Health & social care | 2025 |
| Lynch and Anderson Properties Limited | Real estate | 2020 |
| Lynsey Holdings Ltd | Health & social care | 2019 |
| Lynwood Park Limited | Real estate | 1988 |
| Lyons Living Ltd | Hospitality | 2025 |
| Lythe Hill (Holdings) Limited | Hospitality | 2015 |
| M & D Property Developers Ltd | Real estate | 2019 |
| M B Plumbing & Heating Ltd | Construction | 2002 |
| M Brierley Plumbing Limited | Construction | 2013 |
| M D Green Heating Ltd | Construction | 2022 |
| M D Services (Andover) Ltd | Wholesale & retail | 2003 |
| M Dhesi Dental Ltd | Health & social care | 2023 |
| M J B Touch Limited | Administrative & support | 2011 |
| M Johnson Funeral Directors Independent Limited | Other services | 2011 |
| M L Window Cleaning Limited | Administrative & support | 2009 |
| M P Drink UK Limited | Wholesale & retail | 2022 |
| M R Compliance Limited | Professional & scientific | 2001 |
| M S Ventilation (South & East) Limited | Manufacturing | 2019 |
| M&B Service Centre Ltd | Wholesale & retail | 2015 |
| M&C Healthcare Limited | Health & social care | 2015 |
| M&M Music Limited | Wholesale & retail | 2000 |
| M&S Property Rental Limited | Financial services | 2018 |
| M&S Shaw Property Investments Ltd | Real estate | 2018 |
| M. Ahmed Refurbishments Limited | Construction | 2014 |
| M. Byrne Builders Limited | Construction | 2014 |