| Liputa Advisory Limited | Professional & scientific | 2025 |
| Liquidair Ltd | Construction | 2009 |
| Lisa Britnell Educational Psychology Services Ltd | Education | 2026 |
| LIT Electrical Installations Ltd | Construction | 2023 |
| Lite Business Solutions Ltd | Other services | 2018 |
| Little Canada Limited | Wholesale & retail | 2021 |
| Little House of Beauty (LHB) Ltd | Other services | 2020 |
| Little India Express Limited | Hospitality | 2024 |
| Little Muddy Paws Ltd | Wholesale & retail | 2021 |
| Little Noise Limited | Information & communication | 2021 |
| Little Pink Ghost Ltd | Information & communication | 2023 |
| Little Skin Room Ltd | Other services | 2024 |
| Little Village Shop Limited | Information & communication | 2023 |
| LITTLEBEAR1 Ltd | Information & communication | 2012 |
| Littledale Holidays Ltd | Hospitality | 2022 |
| Litton Solutions Ltd | Professional & scientific | 2022 |
| Livebox Ltd | Other services | 2025 |
| Living Pages Limited | Information & communication | 2026 |
| LIVINGSPACE3 Limited | Real estate | 2003 |
| Livvydon Limited | Construction | 2021 |
| Liza ANN Macintyre Consultancy Limited | Administrative & support | 2011 |
| Lizard Holdings Ltd | Hospitality | 2015 |
| LJ Builds Ltd | Construction | 2026 |
| LJP Building Services Limited | Construction | 2015 |
| LJP Prop Co Limited | Households | 2024 |
| LJT Joiners Limited | Construction | 2017 |
| Lkreative Limited | Professional & scientific | 2016 |
| Llama Group Limited | Construction | 2005 |
| Llewellyn Gray Ltd | Professional & scientific | 2018 |
| LLG Limited | Real estate | 2025 |
| Llhconsult Ltd | Professional & scientific | 2026 |
| LLL Hold Ltd | Hospitality | 2024 |
| LMH Access Limited | Construction | 2024 |
| LMJ Capital Limited | Financial services | 2020 |
| LMN Cleaning Academy Ltd | Administrative & support | 2021 |
| Lmoj Property Investments Limited | Real estate | 2022 |
| LN Projects Limited | Construction | 2011 |
| LNB Facades & Cladding Ltd | Construction | 2019 |
| Loaded for Bear Ltd | Extraterritorial | 2022 |
| Local Publishing Ltd | Manufacturing | 2011 |
| Lodeum Limited | Education | 2024 |
| Lodge Court Leavesden Limited | Households | 1994 |
| Loftus Construction Solutions Ltd | Construction | 2014 |
| Logan-Charlotte Consultancy Limited | Professional & scientific | 2023 |
| Logiflow Ltd | Transport & logistics | 2026 |
| Logistic Express Ltd | Transport & logistics | 2014 |
| Loi's Estates and Investments Ltd | Real estate | 2022 |
| Loi's Launderette and DRY Cleaners Ltd | Wholesale & retail | 2017 |
| Lomax Brothers Construction Limited | Construction | 2019 |
| Lombard Consultancy Limited | Professional & scientific | 2019 |
| Lomo AI Limited | Information & communication | 2026 |
| London Business Aviation Ltd | Manufacturing | 2021 |
| London Chamber of Education Ltd | Education | 2019 |
| London City Real Estates Limited | Real estate | 2010 |
| London Code Ltd | Information & communication | 2013 |
| London College of Make-Up Limited | Education | 2012 |
| London College of United Knowledge Ltd | Education | 2012 |
| London Colney Funeral Services Limited | Financial services | 2013 |
| London Colney Youth Project Limited | Health & social care | 1995 |
| London Dream Properties Ltd | Real estate | 2024 |
| London Drone Company Ltd | Construction | 2017 |
| London Elite Chauffeurs Services Ltd | Transport & logistics | 2025 |
| London Film Cars Limited | Transport & logistics | 2014 |
| London Joinery by Design Ltd | Construction | 2021 |
| London Musical Instruments Limited | Manufacturing | 2009 |
| London Road Markyate Management Limited | Administrative & support | 2008 |
| London Salad Bar Ltd | Wholesale & retail | 2022 |
| London School of Creativity Ltd | Information & communication | 2013 |
| London Software Tech Ltd | Information & communication | 2024 |
| London Specialist Orthodontic Practice Limited | Health & social care | 1996 |
| London Staff Bureau Limited | Administrative & support | 1987 |
| London Street Art Ltd | Other services | 2020 |
| London Structural Solutions Limited | Construction | 2016 |
| London Transport & Lifting Ltd | Transport & logistics | 2021 |
| London Water Services Ltd | Manufacturing | 2021 |
| Lonely World Music and Stage Productions Ltd | Arts & recreation | 2024 |
| Long Chaulden Management Limited | Households | 2021 |
| Long Reach Investments Limited | Financial services | 1961 |
| Long Time NO SEE Ltd | Information & communication | 2026 |
| Longford Shanley Project Management Services Limited | Professional & scientific | 2001 |
| Longshaw Consulting Group Limited | Administrative & support | 2016 |
| Longtail Trading Ltd | Wholesale & retail | 2025 |
| Longworld Limited | Real estate | 2000 |
| Lonsdale Benefit Consultants Limited | Professional & scientific | 2003 |
| Lonsdale Pension Trustees Limited | Financial services | 2003 |
| Lonsdale Services Limited | Financial services | 2002 |
| Lonsdale Wealth Management Ltd | Financial services | 2009 |
| Look at This Limited | Wholesale & retail | 2018 |
| Look Smart Limited | Other services | 2008 |
| Loom & Last Limited | Manufacturing | 2006 |
| LOR Aweni Ltd | Professional & scientific | 2022 |
| Lore and Eddie's Joinery Ltd | Construction | 2019 |
| Loreto College (ST Albans) | Education | 2012 |
| Lost Club London Ltd | Manufacturing | 2025 |
| Lotara Coaching Ltd | Other services | 2025 |
| Lottery Winners Music Ltd | Arts & recreation | 2022 |
| Lotus Bakeries UK Limited | Manufacturing | 2005 |
| Lotus Health Group Ltd | Health & social care | 2015 |
| Lotus Tender Care Ltd | Administrative & support | 2022 |
| Louis Coca Ltd | Wholesale & retail | 2019 |