| JF Investing Ltd | Professional & scientific | 2023 |
| Jgarcia Limited | Administrative & support | 2026 |
| JH Electrical Services Ltd | Construction | 2021 |
| JH Product Services Ltd | Construction | 2022 |
| JHR Housing Ltd | Real estate | 2021 |
| JK & P Properties Limited | Real estate | 2018 |
| JK Hauliers Ltd | Transport & logistics | 2015 |
| JK Logistics Ltd | Administrative & support | 2020 |
| JK Properties Group Limited | Real estate | 2025 |
| JL Digital Ltd | Other services | 2016 |
| JLR Building Contracts LLP | | 2021 |
| JLR Repairs Ltd | Wholesale & retail | 2026 |
| Joey RA Services Limited | Professional & scientific | 2018 |
| John Peters Construction Limited | Construction | 2012 |
| Johnny's Construction and Props Ltd | Manufacturing | 2023 |
| Jones Group Consulting Ltd | Professional & scientific | 2026 |
| JR Builds Ltd | Real estate | 2017 |
| JRB Contractors Ltd | Administrative & support | 2015 |
| JRM Electrical Solutions Ltd | Construction | 2024 |
| JS Concrete Ltd | Transport & logistics | 2019 |
| Junior Strength Academy Ltd | Arts & recreation | 2019 |
| Jupiter Sterling Ltd | Professional & scientific | 2025 |
| Jxmedical Limited | Education | 2022 |
| K & J Roofing Contractors Ltd | Construction | 2024 |
| K & K Confectionary Ltd | Wholesale & retail | 2023 |
| K D Suri Builders Limited | Construction | 2005 |
| K S Aulakh Services Limited | Financial services | 2014 |
| K8 Consulting Services Ltd | Information & communication | 2017 |
| KAIZEN27 Ltd | Information & communication | 2024 |
| Kanisha Limited | Manufacturing | 2025 |
| Kapoor Properties Group Limited | Real estate | 2025 |
| Karam Estates Limited | Real estate | 2021 |
| Kashvi Technosoft Ltd | Information & communication | 2018 |
| Kaytex Properties Limited | Real estate | 2017 |
| Kbrn Limited | Construction | 2019 |
| KD & Partners Ltd | Professional & scientific | 2024 |
| Keates Holdings Limited | Real estate | 2022 |
| Kevin Bird Garages Limited | Wholesale & retail | 2005 |
| Key Property Renovations Ltd | Real estate | 2025 |
| Khurl Construction Limited | Construction | 2003 |
| Kiernan Investments Limited | Financial services | 2021 |
| Kiernan Structural Steel UK Limited | Construction | 2017 |
| Kimbolton Lodge Limited | Health & social care | 1997 |
| Kinley Construction Ltd | Construction | 2022 |
| Kinley Projects Ltd. | Construction | 2017 |
| Kintherm Limited | Construction | 2020 |
| Kiranxbeauty Ltd | Arts & recreation | 2025 |
| Kjet Group Ltd | Real estate | 2022 |
| Kkang Services Limited | Wholesale & retail | 2019 |
| Knightsbridge Office Services Ltd | Administrative & support | 2012 |
| Knrm Limited | Real estate | 2025 |
| Konda Software Limited | Information & communication | 2024 |
| Kossway Trustees Limited | Administrative & support | 2022 |
| KSG Accountants Limited | Professional & scientific | 2018 |
| Ksgakg Ltd | Real estate | 2022 |
| Ksjf Limited | Real estate | 2016 |
| KT Fintech Consulting Ltd | Professional & scientific | 2021 |
| Kulabb Ltd | Information & communication | 2024 |
| Kundan International Limited | Hospitality | 2017 |
| Kunhal Ltd | Health & social care | 2012 |
| Kvgm Limited | Real estate | 2011 |
| KWW Transport Services Ltd | Transport & logistics | 2024 |
| KYF Air Conditioning & Refrigeration Ltd | Construction | 2026 |
| L H Matthew Services Solutions Limited | Administrative & support | 2019 |
| L M Chauffeurs Ltd | Transport & logistics | 2026 |
| L V R Property Services Ltd | Real estate | 2025 |
| LA Palma Italian Restaurant Ltd | Hospitality | 2015 |
| LA Palma Online Takeaway Services Ltd | Hospitality | 2023 |
| Landco Homes Limited | Construction | 2023 |
| Landsberg International Limited | Transport & logistics | 2025 |
| Lastingham Court Management Co. Limited | Households | 1985 |
| Lavique Boutique Ltd | Wholesale & retail | 2025 |
| LD Media Associates Ltd | Information & communication | 2023 |
| Legaleagle Training Limited | Administrative & support | 2008 |
| Lencois Consultancy Limited | Professional & scientific | 2021 |
| Lencois Property Limited | Real estate | 2020 |
| Let's Automate Limited | Wholesale & retail | 1999 |
| Levonne Consultancy Limited | Information & communication | 2013 |
| Lexem Homes Ltd | Real estate | 2025 |
| LIA LOI Aesthetics Ltd | Other services | 2023 |
| Lineage Consulting Limited | Information & communication | 2026 |
| Linkside Enterprise Properties Limited | Real estate | 1993 |
| Lion Records Official Ltd | Information & communication | 2018 |
| Liquidation Nation Ltd | Wholesale & retail | 2024 |
| Livinitup Ltd | Real estate | 2021 |
| Liyanage & Lambeth Limited | Administrative & support | 2020 |
| Lizzie Clitheroe Consulting Ltd | Professional & scientific | 2023 |
| LJE Construction Ltd | Construction | 2026 |
| Logistic's LW Ltd | Wholesale & retail | 2018 |
| London Drainage Solutions Limited | Water & waste | 2019 |
| London Drains Direct Limited | Water & waste | 2013 |
| London Goods Ltd | Transport & logistics | 2020 |
| London Goods Transport Limited | Transport & logistics | 2011 |
| London Motors&Motors Ltd | Wholesale & retail | 2022 |
| London Plumbing and Heating Direct Limited | Construction | 2011 |
| London Timber Buildings Ltd | Construction | 2015 |
| Long Lane 12 Ltd | Real estate | 2025 |
| Longfellow Road Ltd | Real estate | 2026 |
| Lotusmind Consulting Ltd | Extraterritorial | 2024 |
| LRM Group Ltd | Construction | 2025 |