| LAB 9 Ltd | Professional & scientific | 2023 |
| Labelled Drinks Ltd | Wholesale & retail | 2025 |
| Lace Properties Limited | Extraterritorial | 1987 |
| Laetitia Antonowicz Consulting Limited | Administrative & support | 2012 |
| Lagazine African Grocery Limited | Wholesale & retail | 2025 |
| Lakeview Brampton Limited | Real estate | 2025 |
| Lamande & Co Limited | Real estate | 2015 |
| Lamberti Ltd | Real estate | 2022 |
| Lamena Ltd | Health & social care | 2023 |
| Lamey Land & Properties Ltd | Real estate | 2019 |
| Lancaster Corporate Services Ltd | Administrative & support | 2016 |
| Lancaster Enterprises Ltd | Professional & scientific | 2017 |
| Lance and Lucy Ltd | Wholesale & retail | 2024 |
| Land Management (Hemingford) Limited | Real estate | 2020 |
| Lane & Partners Franchise Limited | Real estate | 2002 |
| Langford Business Services Ltd | Professional & scientific | 2006 |
| Lango Transport Ltd | Transport & logistics | 2018 |
| Lano Limited | Professional & scientific | 2006 |
| Larson & Hutchison Limited | Hospitality | 2014 |
| Lartius Ltd | Information & communication | 2015 |
| LAS Signalling Ltd. | Construction | 2015 |
| Laser 2000 (UK) Limited | Wholesale & retail | 1992 |
| Laser Paper Convertors Limited | Real estate | 2000 |
| Lasercut Ltd. | Manufacturing | 2004 |
| Lash Serenity Ltd | Other services | 2024 |
| Latta Hire Limited | Administrative & support | 2009 |
| Lattenbury Services Limited | Administrative & support | 1997 |
| Laurels Estates Property Company Limited | Real estate | 2026 |
| Lavenia D&B Ltd | Construction | 2022 |
| Lawson Media Consultancy Limited | Professional & scientific | 2023 |
| Lawyer Comparison Limited | Information & communication | 2015 |
| Lazio Holiday Letting Ltd | Real estate | 2020 |
| Lazzo Ltd | Hospitality | 2017 |
| LCS Energy Ltd | Construction | 2015 |
| LD Homes Ltd | Professional & scientific | 2025 |
| LE Mark Group Ltd | Administrative & support | 1983 |
| Leadbetter Contracting Ltd | Water & waste | 2024 |
| Leadspark Consultancy Ltd | Professional & scientific | 2025 |
| Leafe & Co Ltd | Professional & scientific | 2015 |
| Leafe Holdings Ltd | Financial services | 2020 |
| Leaflet Distribution Central Ltd | Other services | 2018 |
| Leak Electronics Limited | Extraterritorial | 1984 |
| Leanovate Ltd | Information & communication | 2022 |
| Learn & Bloom Ltd | Education | 2018 |
| Lecaro Specialist Finance Limited | Financial services | 2026 |
| Led.Adam Ltd | Transport & logistics | 2017 |
| Leda International Limited | Other services | 2015 |
| Leda Orthopaedics Limited | Other services | 2013 |
| Leduz Construction Ltd | Construction | 2021 |
| Leeds Day LLP | | 2018 |
| Leeds Day Property Company Limited | Real estate | 2005 |
| Legally Yours Limited | Professional & scientific | 2025 |
| Leigh Pettitt Limited | Transport & logistics | 2003 |
| Leighton Hall Investors Group Ltd | Real estate | 2018 |
| Leistungauto Limited | Wholesale & retail | 2006 |
| Leisure Lockers Limited | Administrative & support | 1992 |
| Leisure Shelters UK Ltd | Administrative & support | 2009 |
| Lenex Trans Ltd | Transport & logistics | 2016 |
| Lennon James Property Limited | Real estate | 2018 |
| Lenton Technology Limited | Information & communication | 2019 |
| Leon Technology Limited | Manufacturing | 2018 |
| Leopop Ltd | Wholesale & retail | 2026 |
| Leroiv Viorel Ltd | Transport & logistics | 2020 |
| Leslaw Lapszynski Ltd | Transport & logistics | 2014 |
| Lesloths Ltd | Wholesale & retail | 2022 |
| Less Pests Limited | Administrative & support | 2018 |
| Let's Go Skate C.I.C. | Arts & recreation | 2017 |
| Lets Kick IT Group Ltd | Arts & recreation | 2023 |
| Lets Kick IT Sports Academy Ltd | Education | 2025 |
| Lexsam Capital Limited | Real estate | 2016 |
| Lf-Va Limited | Administrative & support | 2023 |
| LF6 Limited | Hospitality | 2024 |
| LG Architecture Limited | Professional & scientific | 2025 |
| LGM Accounting Services Ltd | Professional & scientific | 2023 |
| LGM Logistics Limited | Transport & logistics | 2026 |
| Lgmconstruct Ltd | Manufacturing | 2021 |
| LGR Academy Limited | Education | 2022 |
| LGR Health Care Limited | Administrative & support | 2016 |
| LGR X1 Limited | Arts & recreation | 2022 |
| LHS Property Management Ltd | Real estate | 2022 |
| Liberty Group Limited | Real estate | 1954 |
| LIF Services Ltd | Transport & logistics | 2016 |
| Life Applications Ltd | Information & communication | 2025 |
| Life Coaching With Silvana Ltd | Other services | 2016 |
| Lifeline Recruitment Services Limited | Administrative & support | 2016 |
| Lifting Equipment Engineers Association Limited | Other services | 1998 |
| Lightbox Consulting Limited | Administrative & support | 2005 |
| Lighthouse Family Investment Company Limited | Financial services | 2026 |
| LIL Packaging Limited | Manufacturing | 1985 |
| Lila Digital Agency Ltd | Wholesale & retail | 2021 |
| Lime Kiln Lane Management Company Limited | Households | 1990 |
| Limegate & Co Ltd | Professional & scientific | 2013 |
| Limegate Consulting Limited | Professional & scientific | 2024 |
| Limetree Printing Limited | Manufacturing | 2021 |
| Limevine Limited | Real estate | 1990 |
| Limevine Properties Limited Liability Partnership | | 2002 |
| LIN Consulting Limited | Professional & scientific | 2018 |
| Lina's Alts Ltd | Manufacturing | 2023 |
| Linclare Place Eaton Socon Management Company Limited | Real estate | 1984 |
| Line Control Limited | Information & communication | 2025 |