| KVT (PVT) Limited | Real estate | 2025 |
| KWH Services Limited | Construction | 2015 |
| KWL Projects Ltd | | 2024 |
| KYS & AMS Ltd | Wholesale & retail | 2025 |
| L & J Property Maintenance Limited | Administrative & support | 2025 |
| L & N Management Ltd | Other services | 2026 |
| L and Sons Upvc Limited | Construction | 2021 |
| L M 2025 Property Developments Ltd | Construction | 2025 |
| L M Initiatives Limited | Administrative & support | 2011 |
| L N I Ltd | Construction | 2016 |
| L Thomas @ Co Cleaning Services Ltd | Administrative & support | 2025 |
| L Turrell & Sons Transport Ltd | Transport & logistics | 2021 |
| L&B Wholesale Meat Ltd | Wholesale & retail | 2023 |
| L&L PVT Ltd | Health & social care | 2016 |
| L&M Breeding Ltd | Administrative & support | 2015 |
| L.I.T.S. Limited | Administrative & support | 2002 |
| LA Keys Ltd | Real estate | 2022 |
| LA LA LA Limited | Other services | 2018 |
| LA London Group Limited | Construction | 2019 |
| LA Terre Estates Ltd | Real estate | 2024 |
| LAB Eight Architectural Design Consultancy Ltd | Professional & scientific | 2025 |
| Labinjoh London Ltd | Manufacturing | 2011 |
| Labint Inc. Limited | Information & communication | 2024 |
| Labradoodle.Me Ltd | Other services | 2020 |
| Lactronics Group Limited | Information & communication | 2022 |
| Ladega Limited | Wholesale & retail | 2023 |
| Ladtract (Maintenance & Construction) Limited | Construction | 1995 |
| Lafford Co Ltd | Wholesale & retail | 2006 |
| Laitar Technology Services Ltd | Information & communication | 2026 |
| Lakedale Court Management Company Limited | Households | 2019 |
| Lale London Couture Ltd | Wholesale & retail | 2024 |
| Laliné Ltd | Wholesale & retail | 2023 |
| Lambeth Road Management Company Ltd | Real estate | 2025 |
| Lamorna Trading Ltd | Wholesale & retail | 2022 |
| Lamplight Property Ltd | Real estate | 2020 |
| Lampoo Ltd | Wholesale & retail | 2021 |
| Landon Education Group Limited | Financial services | 2026 |
| Landon Education Limited | Education | 2023 |
| Landon School Bromley Limited | Education | 2026 |
| Landvaettir Commons Ltd | Financial services | 2024 |
| Landway Consulting Ltd | Professional & scientific | 2022 |
| Langford Walker Developments Limited | Real estate | 2011 |
| Langford Walker Holdings Limited | Financial services | 2022 |
| Langford Walker Limited | Construction | 2013 |
| Langford Walker Properties Limited | Real estate | 2016 |
| Langley Carehab Ltd | Health & social care | 2024 |
| Langley Park Partners Ltd | Financial services | 2012 |
| Language Link (UK) Limited | Administrative & support | 1993 |
| Lansdown Asset Management Limited | Real estate | 2011 |
| Lansdown Goldman Klein Limited | Real estate | 2020 |
| Lansdowne Consultancy Limited | Professional & scientific | 2011 |
| Lanta Core Construction Ltd | Construction | 2025 |
| Lantern Close Residents Limited | Real estate | 2010 |
| Larry J Entertainment Ltd | Information & communication | 2024 |
| Lash Bar Petts Wood Ltd | Other services | 2018 |
| Lashes ETC Ltd | Other services | 2023 |
| Lasiri Limited | Real estate | 2024 |
| Lastultra Limited | Information & communication | 2025 |
| Latent Consulting Ltd | Professional & scientific | 2021 |
| Latitude Living Ltd | Real estate | 2017 |
| Latitude Living Sourcing Ltd | Real estate | 2018 |
| Latius Property Ltd | Real estate | 2023 |
| Latvito Ltd | Construction | 2026 |
| LAU Family Holdings Limited | Real estate | 2025 |
| Launch LAB Limited | Professional & scientific | 2014 |
| Laura Hewitt Holdings Limited | Financial services | 2026 |
| Laura's Larder Ltd | Wholesale & retail | 2019 |
| Laurel Safe Limited | Administrative & support | 2017 |
| Lauren Dyer Limited | Professional & scientific | 2024 |
| Lauross Limited | Real estate | 2023 |
| Lavalia Ltd | Wholesale & retail | 2011 |
| Lavya Incorporated Limited | Wholesale & retail | 2022 |
| Law Station Platform Limited | Education | 2026 |
| Lawson Letts Ltd | Real estate | 2020 |
| Laxmi Houses Ltd | Real estate | 2023 |
| LAY Witnesses for Christ International - United Kingdom | Education | 2011 |
| Layer Project Management Ltd | Professional & scientific | 2026 |
| Laytrees Limited | Households | 1996 |
| LBD Interiors Limited | Construction | 2013 |
| LC Properties Investment Ltd | Construction | 2021 |
| Lcas Partners Ltd | Administrative & support | 2024 |
| LD Coaching and Consultancy Limited | Professional & scientific | 2021 |
| LDN Applications Ltd | Professional & scientific | 2026 |
| LE Brun Antiques & Works of Art Limited | Administrative & support | 2016 |
| LEA Printers LLP | | 2010 |
| LEA Printers Plus Ltd | Manufacturing | 2023 |
| Leafsquare Media Ltd | Information & communication | 2014 |
| Leak Rescue Ltd | Construction | 2025 |
| Leanne Crawley Studio Ltd | Professional & scientific | 2025 |
| Leap Grid Consultancy and Investment Limited | Administrative & support | 2022 |
| Leasure Home Ltd | Wholesale & retail | 2026 |
| Leatherby Consulting Ltd | Professional & scientific | 2023 |
| Leba Limited | Administrative & support | 2008 |
| Lebre Properties Limited | Real estate | 2002 |
| LEE Estate Lettings Limited | Real estate | 2016 |
| Lefevre Capital Ltd | Real estate | 2020 |
| Legal RM Limited | Information & communication | 2006 |
| Leigh Powell Property Holdings Limited | Real estate | 2022 |
| Leigh Properties Management Ltd | Households | 2026 |
| Leisure Venture Properties Ltd | Real estate | 2023 |