| Kristal Property Investments (Upminster) Limited | Real estate | 2021 |
| Kristal Property Investments Limited | Real estate | 2002 |
| KRS Consulting Ltd | Health & social care | 2024 |
| KS Dental Limited | Health & social care | 2023 |
| KT Connects Ltd | Professional & scientific | 2023 |
| KTL Investments Limited | Real estate | 2019 |
| KTM9 Ltd | Wholesale & retail | 2026 |
| KTW Entertainment Limited | Arts & recreation | 2021 |
| Kube Hair Design Limited | Other services | 2007 |
| Kubrick Construction Limited | Construction | 2012 |
| Kuki Gora Ltd | Health & social care | 2021 |
| Kumarun Foods Limited | Hospitality | 2025 |
| Kuzara Limited | Real estate | 2026 |
| KV Groundworks Ltd | Construction | 2024 |
| KVM Wellness Limited | Health & social care | 2023 |
| KVP Investments Limited | Real estate | 2023 |
| KVS Servicing Limited | Wholesale & retail | 2023 |
| KVS Transport Ltd | Transport & logistics | 2021 |
| Kwahiri Limited | Wholesale & retail | 2006 |
| KWB Investments Ltd | Professional & scientific | 2024 |
| Kwtm Limited | Professional & scientific | 2012 |
| Kyklos Ltd | Professional & scientific | 2024 |
| Kyoto Limited | Administrative & support | 1993 |
| Kyrios Tech Ltd | Other services | 2025 |
| L & B Scaffolding Southern Limited | Professional & scientific | 2003 |
| L & L Care Solutions Limited | Health & social care | 2025 |
| L & M Consulting Limited | Professional & scientific | 2013 |
| L & P Deacon Ltd | Other services | 2014 |
| L and M Botting Developments Limited | Real estate | 2019 |
| L B Wizards Ltd | Administrative & support | 2009 |
| L M Edwards Bespoke Cabinetry & Joinery Ltd | Manufacturing | 2020 |
| L Wormald Ltd | Information & communication | 2016 |
| L&K Productions Ltd | Other services | 2019 |
| L'Artiphartie Ltd | Real estate | 2005 |
| L.Ragu Limited | Real estate | 2026 |
| L.T.C. Roofing and Building Services Ltd | Construction | 2015 |
| L.T.W. Systems Limited | Wholesale & retail | 1994 |
| LA Cuerdy Consultants Ltd | Professional & scientific | 2023 |
| LA Riviera Italian Restaurant Lewes Ltd | Hospitality | 2026 |
| LA Ronde Court RTM Company Limited | Households | 2009 |
| Laad Ltd | Health & social care | 2021 |
| Laandgraaf Limited | Real estate | 2015 |
| Lady Bay Dental Holdings Ltd | Health & social care | 2019 |
| Lady Penelope PUB Co Ltd | Hospitality | 2018 |
| Lagarrigue (Properties) Limited | Real estate | 2000 |
| Laguna Sunrise Ltd | Information & communication | 2025 |
| Laid-Back Films Ltd | Information & communication | 2011 |
| Lake Coniston Ltd | Extraterritorial | 2015 |
| Lake Group Holdings Limited | Financial services | 2024 |
| Lake Group Properties Limited | Real estate | 2022 |
| Lamanna Ltd | Professional & scientific | 2021 |
| Lamberti Chiropractic Ltd | Health & social care | 2018 |
| Lamont Court (Freehold) Company Limited | Households | 2014 |
| Lamont Court RTM Company Limited | Households | 2014 |
| Lampy Limited | Real estate | 2020 |
| Lancaster House Dental Limited | Health & social care | 2026 |
| Lancefield Design Ltd | Professional & scientific | 2024 |
| Landlord Compliance Specialists Ltd | Administrative & support | 2023 |
| Landmark Labs Ltd. | Professional & scientific | 2019 |
| Lanes Construction Limited | Construction | 2012 |
| Langcross Holdings Ltd | Extraterritorial | 2023 |
| Langley House (Residents Association) Limited | Households | 1986 |
| Langmanis Limited | Information & communication | 2005 |
| Language School 360 Ltd | Information & communication | 2020 |
| Language Services (Cauk) | Professional & scientific | 2022 |
| Lannon Media Limited | Information & communication | 2021 |
| Lans Renewables Ltd | Energy | 2026 |
| Lansburys International Limited | Professional & scientific | 2001 |
| Lansdowne Court Management Company (Eastbourne) Limited | Households | 1995 |
| Lansdowne Investment South East Limited | Financial services | 2017 |
| Laora Limited | Professional & scientific | 2023 |
| Laptop Station Limited | Wholesale & retail | 2011 |
| Lara Gent Lettings Ltd | Real estate | 2021 |
| Larcombe Group Ltd. | Wholesale & retail | 2015 |
| Lasciac Limited | Construction | 2022 |
| Laser & Skin Solutions Ltd | Other services | 2023 |
| Lasgo Chrysalis Limited | Wholesale & retail | 1978 |
| Lasgo Records Ltd | Administrative & support | 2022 |
| Lasgo Worldwide Media Limited | Extraterritorial | 2022 |
| Last Trucker Ltd | Transport & logistics | 2026 |
| Lathom House (Eastbourne) Limited | Real estate | 2017 |
| Laura Deetman Ltd | Information & communication | 2021 |
| Laura Rosalind Cleaning Limited | Administrative & support | 2025 |
| Laurawealth JJ Limited | Wholesale & retail | 2026 |
| Laurence Crow Ltd | Agriculture & fishing | 2008 |
| Lava Angels Limited | Professional & scientific | 2014 |
| Lavender Teal Limited | Households | 2018 |
| Law Holding Limited | Professional & scientific | 2017 |
| Lawns Maintenance Limited(The) | Households | 1965 |
| Lawrence Utilities Limited | Construction | 2011 |
| Lawridge Accountants Limited | Professional & scientific | 2017 |
| Lawton Hope Ltd | Administrative & support | 2008 |
| Layercode Limited | Information & communication | 2021 |
| LBK Consultancy Limited | Financial services | 2025 |
| Lbtk Ltd | Other services | 2025 |
| LBW Property Group Ltd | Real estate | 2025 |
| LCN Medical Services Ltd | Health & social care | 2019 |
| LCR Pictures Limited | Arts & recreation | 2003 |
| LDG Autos Ltd | Wholesale & retail | 2022 |
| LDG Investments Limited | Real estate | 2022 |