| Lingtec Limited | Information & communication | 2009 |
| Linx Consultants Ltd | Information & communication | 2019 |
| Linx Technology Associates Limited | Professional & scientific | 2017 |
| Lion Bros Co Ltd | Wholesale & retail | 2019 |
| Lion Corporation Ltd | Professional & scientific | 2018 |
| Lion Motors Ltd | Wholesale & retail | 2024 |
| Liquid Stars Limited | Professional & scientific | 2021 |
| Liquidware Labs Limited | Wholesale & retail | 2015 |
| Liro Carpentry Ltd | Construction | 2025 |
| Listen Talk Inspire LLP | | 2025 |
| Lister Mews Management Co Ltd | Households | 2012 |
| Little Gurkha Chef Ltd | Hospitality | 2018 |
| Little House Creative Ltd | Information & communication | 2026 |
| Little Lucy's Limited | Wholesale & retail | 2015 |
| Little Sparks Electrical Limited | Construction | 2024 |
| Little Wellies Childcare Limited | Health & social care | 2022 |
| Litus Digital Ltd | Professional & scientific | 2016 |
| Liven Creative Limited | Professional & scientific | 2010 |
| Livv Products Limited | Wholesale & retail | 2024 |
| LIZ & ZIE Limited | Professional & scientific | 2012 |
| Ljsi Property Services Limited | Construction | 2019 |
| LLH Home Improvements Ltd | Construction | 2023 |
| LMR Comms Ltd | Information & communication | 2019 |
| Loaded With Love Ltd | Hospitality | 2025 |
| Local Estates Ltd | Real estate | 2025 |
| Lockrite Security Limited | Administrative & support | 2000 |
| Locksure Limited | Other services | 2009 |
| Locus Software Ltd | Information & communication | 2007 |
| Lodsworth Construction Ltd | Construction | 2022 |
| Lodsworth Group Ltd | Construction | 2024 |
| Logic Services Limited | Administrative & support | 2015 |
| Lomast Ltd | Other services | 2022 |
| Loncad Holdings Ltd | Professional & scientific | 2019 |
| London Fire Consultants Ltd | Other services | 2018 |
| London IX Limited | Information & communication | 2025 |
| London Machine Works Ltd | Manufacturing | 2017 |
| London Pro Golf Ltd | Wholesale & retail | 2014 |
| London Processing Centre Limited | Administrative & support | 1993 |
| London Road Capital Project Ltd | Construction | 2024 |
| Long Acre Place Residents Ltd | Households | 2023 |
| Longboat Rond Ltd | Administrative & support | 2021 |
| Longmuir Landscaping Ltd | Administrative & support | 2025 |
| Lonsian Pictures Ltd | Information & communication | 2017 |
| Lookforus Ltd | Professional & scientific | 2020 |
| Loreth Limited | Health & social care | 2024 |
| LOS Roques Productions Limited | Information & communication | 2013 |
| Losc Limited | Professional & scientific | 2017 |
| Love of the Game Limited | Arts & recreation | 2013 |
| Lovely Cards Limited | Wholesale & retail | 2012 |
| Lovethelawn Ltd | Administrative & support | 2018 |
| Loveyour.Support CIC | Education | 2025 |
| Lowman Ventilation Systems Ltd | Construction | 2022 |
| LP SD One Hundred Sixteen Limited | Wholesale & retail | 2023 |
| Lpso Limited | Financial services | 1999 |
| LS Electrical Limited | Construction | 2000 |
| LSR Inventories Limited | Real estate | 2025 |
| LT Dance Ltd | Arts & recreation | 2026 |
| LTS Contracts Ltd | Construction | 2026 |
| Luca Holdings Limited | Real estate | 2018 |
| Lucy Christopher Design Ltd | Information & communication | 2021 |
| Lukamotors Ltd | Transport & logistics | 2026 |
| Luke Barrett Carpentry LLP | | 2024 |
| Lumen Digital Ltd. | Manufacturing | 2017 |
| Lumiere Care Ltd | Health & social care | 2020 |
| Luminosity Lighting Limited | Administrative & support | 2018 |
| Luminous Electric Ltd | Construction | 2014 |
| Lumrem Ltd | Construction | 2017 |
| Lundie Estates Ltd | Construction | 2018 |
| Lush Empires Ltd | Other services | 2023 |
| Luvfud Limited | Wholesale & retail | 2012 |
| Luxe Construction Services LLP | | 2025 |
| Luxe Garden Designs Ltd | Administrative & support | 2025 |
| Luxoft Financial Services UK Limited | Information & communication | 2001 |
| Luxoft UK Limited | Information & communication | 2003 |
| Luxurio Limited | Financial services | 2019 |
| Luxurious Finish LLP | | 2025 |
| Luxury Sleeps (Cotswolds) LLP | | 2020 |
| LW Trade Ltd | Manufacturing | 2023 |
| LX13 Lighting Ltd | Information & communication | 2022 |
| Lyft Derivatives Ltd | Financial services | 2013 |
| Lyphe Clinic Limited | Information & communication | 2018 |
| Lyphe Dispensary Ltd | Wholesale & retail | 2024 |
| Lyphe Subco Limited | Health & social care | 2019 |
| M & J Residential Properties Ltd | Real estate | 2020 |
| M & J Warehouse Limited | Real estate | 1999 |
| M & M Haulage (SW) Ltd | Transport & logistics | 2025 |
| M E Cooke Limited | Professional & scientific | 2013 |
| M E R Developments Ltd | Real estate | 2014 |
| M Finch Electrical Limited | Construction | 2025 |
| M J Events Support Limited | Administrative & support | 2005 |
| M&A Dentmet Ltd | Health & social care | 2007 |
| M&A Prestwich Unlimited | Manufacturing | 2024 |
| M&B Brothers Limited | Construction | 2018 |
| M&J Building Services Limited | Construction | 2018 |
| M&K Bloodstock Limited | Agriculture & fishing | 2022 |
| M&K Car Restoration Limited | Wholesale & retail | 2014 |
| M-Tech IT Solutions Ltd | Information & communication | 2015 |
| M.D.A. Interiors Limited | Manufacturing | 2009 |
| M3 Mediation Limited | Professional & scientific | 2016 |
| MA Mobile Tyres Ltd | Wholesale & retail | 2024 |