| London Improvements Ltd | Construction | 2022 |
| London Lead Company Limited | Administrative & support | 2006 |
| London Lighthouse Limited | Other services | 2013 |
| London Quals Solutions Ltd | Education | 2024 |
| London Resource Recovery Ltd | Wholesale & retail | 2019 |
| London Security Chauffeurs Group Limited | Transport & logistics | 2015 |
| London Shooting Club Ltd | Arts & recreation | 2021 |
| London Warriors Events Ltd | Real estate | 2022 |
| London Water Softening Ltd | Manufacturing | 2019 |
| Londonit Limited | Extraterritorial | 2008 |
| Londonit.Co.Uk Limited | Extraterritorial | 2008 |
| Lonely Girls Club Ltd | Arts & recreation | 2024 |
| Long Meadows Management Ltd | Professional & scientific | 2025 |
| Long Stack Limited | Administrative & support | 2025 |
| Longs Bait & Tackle Ltd | Wholesale & retail | 2021 |
| Loomhaven Ltd. | Wholesale & retail | 2024 |
| Lord Williams's School Day Nursery | Education | 2001 |
| Lordclaim Residents Association Limited | Administrative & support | 1984 |
| Lorenzzouk Ltd | Construction | 2016 |
| LOS Azahares Company Limited | Households | 1983 |
| LOT to Buy (LTB) Ltd | Wholesale & retail | 2015 |
| Lote Organics Limited | Wholesale & retail | 2025 |
| Lottie Trading Limited | Hospitality | 2015 |
| Lottoracing Limited | Professional & scientific | 2015 |
| Lotuly Ltd | Information & communication | 2019 |
| Lotus Advisory Services Limited | Professional & scientific | 2025 |
| Lotus POT Limited | Hospitality | 2025 |
| Lotus Productions Limited | Other services | 2018 |
| Louca Electrical Ltd | Construction | 2020 |
| Loudwater Computing Limited | Information & communication | 2004 |
| Loudwater Developments Limited | Real estate | 2005 |
| Loudwater Maintenance Limited | Real estate | 2018 |
| Louise Grace (UK) Limited | Other services | 2012 |
| Lounge Restaurants and Catering Services Ltd | Hospitality | 2023 |
| Love Fitness (JM) Limited | Arts & recreation | 2016 |
| Love LED Coaching Limited | Professional & scientific | 2015 |
| Love Nail Salon Limited | Other services | 2022 |
| Loves Pilgrim Ltd | Information & communication | 2019 |
| Lower Mead Limited | Administrative & support | 2010 |
| Lower Your Shoulder Music Ltd | Administrative & support | 2013 |
| Lowes Mows Ltd | Administrative & support | 2021 |
| Lowlands Cottages Management Company Limited | Households | 2003 |
| Loyal Support Services Ltd | Health & social care | 2021 |
| LP London Ltd | Manufacturing | 2023 |
| LPC Properties Limited | Extraterritorial | 2014 |
| Lpjp Services Ltd | Information & communication | 2026 |
| Lpme Limited | Wholesale & retail | 2014 |
| LR BIZ Solutions Ltd | Professional & scientific | 2024 |
| LR Ownership Limited | Households | 2026 |
| LRC Community Care CIC | Public administration | 2026 |
| LRC Housing Ltd | Real estate | 2026 |
| Lsanders Electrical Limited | Construction | 2022 |
| Lsim Training Ltd | Education | 2020 |
| LSK Futures Limited | Real estate | 2022 |
| Lubekwa Honey Ltd | Wholesale & retail | 2024 |
| Lucan Plastering Ltd | Construction | 2024 |
| Luceo Lighting Ltd | Wholesale & retail | 2025 |
| Lucky Gourmet Kitchen Limited | Hospitality | 2022 |
| Lucky Star Wycombe Limited | Wholesale & retail | 2020 |
| Lucsym Ltd | Transport & logistics | 2026 |
| Lucy C & Associates Ltd | Other services | 2024 |
| Lucy Thomson Media Ltd | Information & communication | 2025 |
| Lucy Victoria Ltd | Other services | 2010 |
| Ludlow Fencing and Landscaping Limited | Administrative & support | 2016 |
| Ludlow House (Maidenhead) Management Limited | Households | 1990 |
| Luke Daniel Churchill Limited | Extraterritorial | 2024 |
| Lulay Construction Ltd | Construction | 2024 |
| Lulupa Ltd | Hospitality | 2023 |
| Lumen Capital Limited | Professional & scientific | 2016 |
| Lumenis BE (UK) Limited | Health & social care | 2021 |
| Lumensy Ltd | Construction | 2019 |
| Lumicity Ltd | Administrative & support | 2010 |
| Lumina Media Capital Limited | Extraterritorial | 2024 |
| Lumina Media Group Limited | Extraterritorial | 2024 |
| Lumina Media Ventures Limited | Extraterritorial | 2024 |
| Lumina Punch Productions Limited | Information & communication | 2024 |
| Lumina Studios Group Limited | Information & communication | 2023 |
| Lumina Studios Nominee Limited | Administrative & support | 2023 |
| Luminary Trading Limited | Arts & recreation | 2009 |
| Luminis Estates Ltd | Real estate | 2025 |
| Lumio Glass Ltd | Construction | 2025 |
| Lumivex Ltd | Professional & scientific | 2024 |
| Lumora International Ltd | Manufacturing | 2025 |
| Luna & Solis Limited | Wholesale & retail | 2020 |
| Lunalux Entertainment Ltd | Professional & scientific | 2024 |
| Lunara Alchemy Ltd | Wholesale & retail | 2025 |
| Lunexis Digital Ltd | Information & communication | 2026 |
| Luri Investments Ltd | Wholesale & retail | 2016 |
| Luri Limited | Financial services | 2016 |
| Lush Property Services Ltd | Construction | 2025 |
| Luso Link Consulting Limited | Professional & scientific | 2024 |
| Lustro Finishes Ltd | Construction | 2025 |
| Luthfa Limited | Real estate | 2024 |
| Luton Business Hub Limited | Manufacturing | 2019 |
| Luxe Horizon Properties Limited | Real estate | 2024 |
| Luxe Line Ltd | Construction | 2025 |
| Luxe Pharma Limited | Health & social care | 2023 |
| Luxe Spa Land Ltd | Other services | 2024 |
| Luxecurrent Ltd | Construction | 2026 |
| Luxion Chauffeur Services Ltd | Transport & logistics | 2018 |