| Longwood Daycare Limited | Health & social care | 2018 |
| Longwood Motor Company Limited | Wholesale & retail | 2006 |
| Longwood Property Management (UK) Ltd | Other services | 2003 |
| Loom Technologies Limited | Information & communication | 2019 |
| Loop Concepts Design Limited | Professional & scientific | 2008 |
| Lord C Ltd | Wholesale & retail | 2026 |
| Lord Property Development Ltd | Real estate | 2025 |
| Lorna Ingram Consulting Ltd | Professional & scientific | 2025 |
| Lorna Young Foundation | Education | 2003 |
| Lornajane Limited | Information & communication | 2010 |
| Lost Circle Ltd | Information & communication | 2021 |
| Lotus Basi Ltd | Public administration | 2025 |
| Lotus Sign & Print Ltd | Manufacturing | 2021 |
| Lotus Trading Ltd | Manufacturing | 2018 |
| Loud Whispers Ltd | Professional & scientific | 2025 |
| Louis-Justin Ltd | Wholesale & retail | 2022 |
| Louisa Gaunt Equine Services Ltd | Arts & recreation | 2023 |
| Louise Joanne Limited | Wholesale & retail | 2024 |
| Louka Studio & Co Ltd | Wholesale & retail | 2025 |
| Love Bread Limited | Manufacturing | 2021 |
| Love HER Style Limited | Wholesale & retail | 2020 |
| Love Laundry (Yorkshire) Ltd | Other services | 2017 |
| Love Luna Limited | Wholesale & retail | 2019 |
| Love to BE..... Limited | Extraterritorial | 2007 |
| Love Your Birth Limited | Education | 2022 |
| Love&Loyalty Limited | Wholesale & retail | 2025 |
| Loveday Media Ltd | Professional & scientific | 2017 |
| Loves Care First Ltd | Health & social care | 2019 |
| LOW Fold Properties Ltd | Real estate | 2002 |
| Lower Edge Developments Limited | Real estate | 2004 |
| Lower HEY Farm Management Company Limited | Households | 2015 |
| Lower Quarry Road Management Company Limited | Households | 2016 |
| Lowkey Stop Ltd | Hospitality | 2025 |
| Loxley Mews RTM Company Limited | Households | 2021 |
| Loyal Soldiers Ltd | Wholesale & retail | 2025 |
| LP Pharma Limited | Wholesale & retail | 2026 |
| LPG Clinics Wholesale Ltd | Wholesale & retail | 2018 |
| LPG Pharma Limited | Wholesale & retail | 2025 |
| LPG Property Construction Ltd | Real estate | 2024 |
| LPK Mortgages Limited | Financial services | 2020 |
| LPL Thornton Limited | Financial services | 2026 |
| LPS 2 Limited | Arts & recreation | 2025 |
| LRK Property Group Ltd | Real estate | 2022 |
| LRM Ventures Limited | Wholesale & retail | 2025 |
| LS2Y Community Services Limited | Administrative & support | 2016 |
| LS2Y Nurseries Limited | Health & social care | 2016 |
| LSJ Properties RL Ltd | Real estate | 2026 |
| LSJ Supermarket Ltd | Wholesale & retail | 2011 |
| LSL West Yorkshire Limited | Transport & logistics | 2025 |
| LSV Coaching Ltd | Professional & scientific | 2020 |
| LTU Auto Ltd | Wholesale & retail | 2026 |
| Luana the Label Ltd | Wholesale & retail | 2021 |
| Lubnum Ltd | Health & social care | 2016 |
| Luca P Catering Limited | Hospitality | 2025 |
| Lucas Business Advisers Ltd. | Professional & scientific | 2009 |
| Lucas LEE Limited | Professional & scientific | 2009 |
| Lucentabyte Global Ltd | Professional & scientific | 2025 |
| Lucharles Healthcare Ltd | Health & social care | 2021 |
| Lucid Peptides Ltd | Wholesale & retail | 2025 |
| Lucid-Biz Limited | Information & communication | 2019 |
| Lucid.Sky Ltd | Real estate | 2024 |
| Luck Lane Cars Ltd | Transport & logistics | 2025 |
| Luck Lane Management Company Limited | Households | 2003 |
| Luckin Big Co., Ltd | Manufacturing | 2024 |
| Lucky Cat Events Limited | Wholesale & retail | 2025 |
| Lucky Corporation Limited | Wholesale & retail | 2020 |
| Lucky Moth Design Ltd | Professional & scientific | 2023 |
| Lucro Liquido Ltd | Financial services | 2021 |
| Lucy Daisy Michele Design Ltd | Arts & recreation | 2024 |
| Luigibiano Logistics Ltd | Transport & logistics | 2026 |
| LUK Siam Thai Massage Limited | Health & social care | 2026 |
| Lumarly Ltd | Wholesale & retail | 2026 |
| Lumen Finance Consulting Ltd | Professional & scientific | 2023 |
| Lumley Asset Management Limited | Financial services | 2005 |
| Lumley Baxter Asset Management LLP | | 2008 |
| Luna Heights Properties Ltd | Real estate | 2026 |
| Lunar Sales Ltd | Wholesale & retail | 2023 |
| Lundie Commercial Limited | Construction | 2018 |
| Lundwood Surgical Services Ltd | Health & social care | 2012 |
| Lunn Commercial Services Ltd | Administrative & support | 2024 |
| Lupa Recruitment Limited | Administrative & support | 2020 |
| Lupe Marketing Limited | Professional & scientific | 2025 |
| Luqmaan Saleem Limited | Information & communication | 2023 |
| Luqman Ltd | Health & social care | 2014 |
| Lutescens Ltd | Information & communication | 2024 |
| LUV to Buy Ltd | Wholesale & retail | 2011 |
| LUW Ltd | Wholesale & retail | 2025 |
| LUX & Belle Limited | Other services | 2024 |
| LUX Assist Ltd | Wholesale & retail | 2026 |
| Lux-Smart Electrics Ltd | Construction | 2016 |
| Luxblinds Ltd | Construction | 2024 |
| Luxe Bakes and Events Ltd | Wholesale & retail | 2026 |
| Luxe Beauty Store Ltd | Wholesale & retail | 2026 |
| Luxe Furniture Ltd | Wholesale & retail | 2025 |
| Luxe Lettings Limited | Real estate | 2008 |
| Luxefront Properties Limited | Real estate | 2024 |
| Luxfitz Ltd | Construction | 2024 |
| Luxora Steam Cleaning Limited | Administrative & support | 2026 |
| Luxs Properties Sourced Ltd | Administrative & support | 2024 |
| Luxury Mattresses Limited | Manufacturing | 2017 |