| Kent Paving and Resin Limited | Administrative & support | 2021 |
| Keshtgar Ltd | Arts & recreation | 2024 |
| Ketco Limited | Other services | 2001 |
| Ketco Properties Limited | Extraterritorial | 2002 |
| Kevin Logistics Ltd | Transport & logistics | 2018 |
| Key West Freehold Limited | Real estate | 2023 |
| KEY2BUILDS Ltd | Construction | 2024 |
| KEY2ITRANSPORT Ltd | Wholesale & retail | 2024 |
| KEY2ITWORLD Ltd | Information & communication | 2024 |
| Keyhold Properties Limited | Real estate | 2024 |
| Kggroup 2019 Ltd | Construction | 2019 |
| KH Financial Services Ltd | Professional & scientific | 2023 |
| Khan Elite Properties Ltd | Real estate | 2025 |
| Kheper Accountancy Ltd | Professional & scientific | 2011 |
| KIN of Sparta Ltd | Real estate | 2017 |
| Kingdom Movers Ltd | Real estate | 2012 |
| Kingfisher Roofing Limited | Construction | 2014 |
| Kiran Holdings Ltd | Real estate | 2023 |
| Kismat the Great Ltd | Hospitality | 2025 |
| KJ Communication Therapy LLP | | 2025 |
| KK Ragini Company Limited | Health & social care | 2011 |
| Kksb Property Ltd | Real estate | 2025 |
| Kkss Property Investment Ltd | Real estate | 2026 |
| KMC Tech Ltd | Information & communication | 2014 |
| KN1GHT Live Limited | Arts & recreation | 2021 |
| KN1GHT Ltd | Information & communication | 2018 |
| Kndb Holdings Ltd | Real estate | 2023 |
| Koch Properties Limited | Hospitality | 2024 |
| Kofi ADU Healthcare Limited | Professional & scientific | 2023 |
| Koira Collection Ltd | Manufacturing | 2021 |
| Koka Steel Fixing Ltd | Construction | 2020 |
| Kolia Quant Private Limited | Financial services | 2023 |
| Kool Smiles Limited | Extraterritorial | 2013 |
| Korabi Construction Ltd | Construction | 2012 |
| Kore Property Management Ltd | Real estate | 2025 |
| Kraj Estates Limited | Real estate | 2026 |
| Krishna Krupa Limited | Real estate | 2025 |
| Kron Thermal Services Ltd | Construction | 2021 |
| Krucx Technologies Limited | Information & communication | 2024 |
| KTM Financials Limited | Professional & scientific | 2008 |
| Ktms Realty Limited | Real estate | 2010 |
| Kulendran Property Limited | Real estate | 2021 |
| Kumar Estates Ltd | Real estate | 2013 |
| KYD Transportti Ltd | Transport & logistics | 2023 |
| Kyra Corp Ltd | Information & communication | 2024 |
| Kyra IT Corporation Ltd | Information & communication | 2024 |
| L R Decoration Ltd | Construction | 2016 |
| L&C Cars Limited | Wholesale & retail | 2023 |
| L&M Change Consulting Ltd | Professional & scientific | 2018 |
| LA Squared Consultancy Limited | Professional & scientific | 2023 |
| Lachani Properties Ltd | Real estate | 2019 |
| Lady Bountiful Limited | Hospitality | 1997 |
| LAL Plumbing and Heating Ltd | Construction | 2023 |
| Lala Investment Ltd | Real estate | 2023 |
| Lambourne Limited | Construction | 2015 |
| Land THS Ltd | Real estate | 2018 |
| Landhra Ltd | Real estate | 2010 |
| Landlord Inspection London Ltd | Construction | 2022 |
| Landminster Developments Limited | Other services | 2001 |
| Lapcom Direct Ltd | Information & communication | 2014 |
| Lauris Commerce Ltd | Wholesale & retail | 2026 |
| Lawrence Properties Limited | Extraterritorial | 2015 |
| Lawyers Consultancy LLP | | 2020 |
| Lawyers Consultants Limited | Real estate | 2023 |
| LC Property Holdings Limited | Real estate | 2020 |
| LCG Couriers Ltd | Transport & logistics | 2026 |
| LDB London Limited | Professional & scientific | 2011 |
| Learn to Drive Essex Ltd | Education | 2024 |
| Lefkara Land Corporation Ltd | Agriculture & fishing | 2013 |
| Legacy Landmark Group Ltd | Construction | 2024 |
| Legacy Property London Ltd | Real estate | 2024 |
| Lehrmann London Limited | Professional & scientific | 2008 |
| Leicester Realtors Ltd | Real estate | 2025 |
| Leveret Arnold Limited | Other services | 2010 |
| Lexat Ltd | Wholesale & retail | 2023 |
| Lidigma Limited | Construction | 2017 |
| Life Vision Movies Ltd | Administrative & support | 2017 |
| Liftcore Group Ltd | Construction | 2026 |
| Liha Bakers Ltd | Manufacturing | 2024 |
| Limes Kitchen Limited | Hospitality | 2026 |
| Limitless Installation Services Ltd | Professional & scientific | 2020 |
| Limitless Skills Ltd | Other services | 2015 |
| Linaden Ltd | Hospitality | 2025 |
| Linetrust International Offshore Limited | Information & communication | 2016 |
| Linra Limited | Information & communication | 2026 |
| Litmus CX Ltd | Professional & scientific | 2025 |
| Livetime Investment Limited | Hospitality | 2013 |
| LIVEWIRE71 Ltd | Construction | 2024 |
| LMG Coffee HUT Ltd | Wholesale & retail | 2025 |
| LMP & Sons Ltd | Real estate | 2011 |
| Lockland Prop Ltd | Real estate | 2024 |
| Loda Trading Limited | Information & communication | 2015 |
| London Asian Events Ltd | Hospitality | 2025 |
| London College of Clinical Medicine Limited | Education | 2025 |
| London College of Emergency Medicine Ltd | Education | 2023 |
| London Cosmetics Clinic Ltd | Health & social care | 2019 |
| London Forecourt Limited | Wholesale & retail | 2018 |
| London Immo Limited | Real estate | 2021 |
| London OFS Property Limited | Real estate | 2026 |
| London Oxygen Centre Ltd | Health & social care | 2024 |