| Lock Sports Horses Ltd | Agriculture & fishing | 2019 |
| Lockside Software Limited | Information & communication | 1995 |
| Lockslea Holdings Limited | Real estate | 2015 |
| Lockstock Interiors Ltd | Wholesale & retail | 2024 |
| Lockstone Business Services Limited | Professional & scientific | 2005 |
| Lode Star Trading Company Limited | Wholesale & retail | 2022 |
| Lofer Hospitality Services Ltd | Hospitality | 2024 |
| Loft Pens Limited | Manufacturing | 2018 |
| Lofty Hydraulics Limited | Professional & scientific | 2024 |
| LOG My Fishing Catches Ltd | Information & communication | 2026 |
| Loge Consulting Limited | Professional & scientific | 2010 |
| Logi Polo UK Limited | Manufacturing | 2017 |
| Logical Electrical Ltd | Construction | 2022 |
| Logicinflux Ltd | Information & communication | 2018 |
| Logicprovider UK Ltd | Information & communication | 2011 |
| Logictree Consulting Limited | Professional & scientific | 2017 |
| Logitek Software Ltd | Information & communication | 2016 |
| Logo Consultancy Ltd | Professional & scientific | 2012 |
| Logs for ALL Limited | Agriculture & fishing | 2013 |
| Lojins Limited | Hospitality | 2007 |
| Lolapalola Limited | Construction | 2008 |
| Loler Inspection Services Ltd | Professional & scientific | 2023 |
| Lomnet Services Limited | Professional & scientific | 2018 |
| London Array Limited | Energy | 2001 |
| London Counselling Practice Limited | Health & social care | 2009 |
| London Fitness Ventures Limited | Arts & recreation | 2025 |
| London Mineral Standards Limited | Professional & scientific | 2018 |
| London Nova Ltd | Wholesale & retail | 2020 |
| London Technical Supplies Limited | Transport & logistics | 2003 |
| Lone Wolf Merchandise & Sportswear Ltd | Manufacturing | 2025 |
| Lonewolf Enterprises Ltd | Information & communication | 2009 |
| Lonewolf PCB Ltd. | Information & communication | 2012 |
| Long Engineering Limited | Manufacturing | 1990 |
| Longbourne Properties Limited | Real estate | 2002 |
| Longevity Studio Ltd | Arts & recreation | 2025 |
| Longford Automotive Art Limited | Professional & scientific | 2026 |
| Longland Technical Solutions Ltd | Professional & scientific | 2019 |
| Longwide Limited | Financial services | 2002 |
| Loodo Ltd | Information & communication | 2025 |
| Look Sharp Roofing Ltd | Construction | 2023 |
| Lorafi Solutions Ltd | Information & communication | 2026 |
| Lord Maslins Ltd | Professional & scientific | 2012 |
| Lord Scaffolding Limited | Construction | 2026 |
| Lordswood Group Limited | Professional & scientific | 2023 |
| Lorraine Bramwell Associates Limited | Professional & scientific | 2001 |
| Lost and Fond Limited | Manufacturing | 2018 |
| Lost in Illustrating Ltd | Arts & recreation | 2025 |
| Lotmead Farm PYO LLP | | 2015 |
| Lottie J Music Ltd | Manufacturing | 2023 |
| Lotus Eater Media Limited | Manufacturing | 2019 |
| Lotus House Zerun Ltd | Extraterritorial | 2020 |
| Lotus Properties (South West) Ltd | Real estate | 2020 |
| Louisa J Rowlands Bespoke Estate Agent Ltd | Real estate | 2023 |
| LOURDES99 Ltd | Arts & recreation | 2025 |
| Lovatts Heating Limited | Construction | 2007 |
| Love & Stitch UK Limited | Wholesale & retail | 2025 |
| Love 2 Care Homecare Services Ltd | Health & social care | 2017 |
| Love Theatre Arts Ltd | Arts & recreation | 2015 |
| Love to Style Ltd | Other services | 2009 |
| Loveday Motors Limited | Wholesale & retail | 2019 |
| Lovegrove Holdings Ltd | Financial services | 2026 |
| Lovemygroomer Ltd | Other services | 2021 |
| Lovial Design Services Ltd | Professional & scientific | 2020 |
| Lowe Property Maintenance Ltd | Construction | 2015 |
| Lowenkraft Ltd | Professional & scientific | 2025 |
| Loxley Construction (Swindon) Ltd | Construction | 2021 |
| Loyal Support Ltd | Health & social care | 2022 |
| Loyalty Beauty Limited | Other services | 2018 |
| LP Carpentry & Construction Ltd | Construction | 2017 |
| Lprj Ltd | Manufacturing | 2026 |
| Lpuk Investments Limited | Real estate | 2026 |
| LR Imaging Ltd | Professional & scientific | 2025 |
| LR Property Management Services Ltd | Real estate | 2019 |
| LRB Property Investments Ltd | Real estate | 2025 |
| LRH Property Holdings Ltd | Real estate | 2025 |
| Lrja Property Ltd | Real estate | 2022 |
| Lrjc Mortgages Limited | Financial services | 2026 |
| LRT Rentals Ltd | Real estate | 2025 |
| LS Venders Ltd | Hospitality | 2022 |
| Lsir Tech Ltd | Information & communication | 2022 |
| LSP Smart Limited | Wholesale & retail | 2022 |
| Lsvtm Limited | Information & communication | 2003 |
| LTB Brickwork & Construction Ltd | Construction | 2023 |
| LTJ Associates Limited | Financial services | 2025 |
| LTL Construction, Carpentry & Fixing Ltd | Construction | 2022 |
| LTM Landscapes Limited | Administrative & support | 2015 |
| LTN Cars Limited | Wholesale & retail | 2025 |
| Luana Companies Ltd | Construction | 2019 |
| Lubritech Limited | Wholesale & retail | 2003 |
| Lucas Andrei Limited | Transport & logistics | 2017 |
| Lucas Precision Engineering Limited | Manufacturing | 2009 |
| Lucian Resourcing Ltd | Construction | 2018 |
| Lucie Ltd | Other services | 2015 |
| Lucilla Properties Limited | Professional & scientific | 2006 |
| Luck Greayer Bloodstock Shipping Limited | Transport & logistics | 2010 |
| Luckton Limited | Construction | 2018 |
| Luckyamora Limited | Hospitality | 2019 |
| Lucy Humphreys Beauty Limited | Other services | 2018 |
| Lucy Lloyd Equestrian Ltd | Other services | 2020 |
| Lucy Rodwell Ltd | Health & social care | 2014 |