| Knockpip Trading Ltd | Wholesale & retail | 2025 |
| Knowledge Healthcare Services Ltd | Health & social care | 2025 |
| Knowledge Share Limited | Education | 2025 |
| KNS Brothers (UK) Ltd | Hospitality | 2024 |
| Kocialkowski Ltd | Health & social care | 2026 |
| Kolev.Vfx Ltd | Information & communication | 2015 |
| Komatik Consulting Limited | Information & communication | 2016 |
| KOR Vehicle Security Ltd | Wholesale & retail | 2019 |
| Kour and Singh Ltd | Real estate | 2024 |
| Kozo Creative Ltd | Information & communication | 2023 |
| Kozo Finance 1 Ltd | Financial services | 2025 |
| Kozo Finance 2 Ltd | Financial services | 2025 |
| Kozo Finance Ltd | Financial services | 2025 |
| Kp&J Ltd | Hospitality | 2024 |
| KPM Commercial Ltd | Administrative & support | 2022 |
| KQ Technology Ltd | Information & communication | 2026 |
| KR8IVE Limited | Hospitality | 2025 |
| Kranzle (UK) Limited | Wholesale & retail | 1986 |
| KRF Corporate Entertainment Limited | Arts & recreation | 2008 |
| Kris Management Consultancy Limited | Information & communication | 2012 |
| Kristaval Keepsakes Limited | Other services | 2009 |
| Krivi Limited | Wholesale & retail | 2023 |
| Krutani Investment Limited | Real estate | 2025 |
| KS Dynamic Consultants Ltd | Construction | 2013 |
| KT Hire Limited | Administrative & support | 2020 |
| KTD Trading Ltd | Wholesale & retail | 2020 |
| Ktech Signs & Print Ltd | Manufacturing | 2025 |
| KW Estates Limited | Administrative & support | 2017 |
| Kxng Limited | Wholesale & retail | 2022 |
| Kyanite Kare Ltd | Health & social care | 2019 |
| L and B Health (Essex) Limited | Health & social care | 2025 |
| L Baglin Mortgage Services Limited | Financial services | 2016 |
| L D Cubix Construction Limited | Construction | 2025 |
| L Dykes Limited | Information & communication | 2023 |
| L P S Trading Ltd | Real estate | 2014 |
| L&I Paterson Limited | Health & social care | 2013 |
| L&J Sandhu Ltd | Real estate | 2024 |
| L'Ancora Restaurant Limited | Hospitality | 2023 |
| L'Oliveta Cafe Restaurant Limited | Hospitality | 2018 |
| L.C. RTM Company Limited | Households | 2021 |
| L.S.E Taxi Rentals Limited | Transport & logistics | 2019 |
| L4 Building Solutions Ltd | Construction | 2018 |
| LA Oana Ltd | Wholesale & retail | 2017 |
| LA Riche Limited | Manufacturing | 1981 |
| LA Romantica Limited | Hospitality | 2016 |
| LAA Haulage Limited | Transport & logistics | 2025 |
| LAB SPV03 Limited | Construction | 2024 |
| Labour Xchange Ltd | Administrative & support | 2015 |
| Labtek Electrical Services Limited | Construction | 2021 |
| Labtek Environmental Holdings Limited | Financial services | 2025 |
| Labtek Environmental Limited | Construction | 2009 |
| Labtek Group Limited | Construction | 2024 |
| Labtek Holdings Limited | Financial services | 2025 |
| Ladies Let’S Business Ltd | Administrative & support | 2024 |
| Lady Hamilton Court RTM Company Limited | Households | 2010 |
| Laika Network Limited | Information & communication | 2015 |
| Lakes Property Developers Limited | Construction | 2014 |
| Lambry Ltd | Construction | 2024 |
| Lancaster Gardens Southend Limited | Households | 2019 |
| Land & Anchor Ltd | Construction | 2012 |
| Land Investments (Rayleigh) Limited | Real estate | 1961 |
| Land Investments (Southend) Limited | Real estate | 1959 |
| Landed Media Limited | Information & communication | 2016 |
| Lanegan Developments Ltd | Construction | 2021 |
| Langalo Ltd | Hospitality | 2021 |
| Langley Healthcare Consultancy Services Ltd | Professional & scientific | 2023 |
| Langly Developments Limited | Financial services | 2003 |
| Langosh Ltd | Transport & logistics | 2017 |
| Langroyd Road Management Company Limited | Households | 2012 |
| Langtree Place (Woking) Management Company Limited | Households | 2018 |
| Languageaid Ltd | Professional & scientific | 2012 |
| Languard View (Dovercourt) Residents Management Company Limited | Households | 2023 |
| Lanski Properties Ltd | Real estate | 2012 |
| Laona Transport Ltd | Transport & logistics | 2016 |
| Lapland Workshop Limited | Other services | 2014 |
| Larrett Clinics Ltd | Health & social care | 2009 |
| LAS Ltd Ltd | Construction | 2026 |
| Laser 24 Limited | Manufacturing | 2007 |
| Latchingdon Pre-School Playgroup Limited | Education | 2008 |
| Latchingdon Sessional Pre-School Limited | Education | 2013 |
| Latgales Kurjers Limited | Transport & logistics | 2023 |
| Launchie Ltd | Professional & scientific | 2025 |
| Launderama (Southend) Limited | Other services | 2018 |
| Lauren Thomas-Clowes Mortgage Advice Limited | Financial services | 2021 |
| Laurence Homes (Boulters Mill) Limited | Construction | 1983 |
| Laurence Homes (Suffolk) Limited | Construction | 2023 |
| Lauryn Jaime Ltd | Professional & scientific | 2022 |
| Lawford Lettings Ltd | Real estate | 2024 |
| Lawin Limited | Other services | 2015 |
| Lawstone Management Ltd | Real estate | 2021 |
| Layerforge 3D Ltd | Manufacturing | 2026 |
| Lazanu Courier Express Limited | Transport & logistics | 2019 |
| Lazarus Property Group Ltd | Financial services | 2025 |
| Lazcol International Ltd | Wholesale & retail | 2025 |
| LB Cleaning Services Limited | Administrative & support | 2015 |
| Lbld Accommodations Thorpe Bay Limited | Hospitality | 2020 |
| LCM Ceilings & Partitions Limited | Other services | 2006 |
| LD Contracting Services Ltd | Professional & scientific | 2018 |
| LDB Real Estate Limited | Real estate | 2017 |
| LDM Cross Ltd | Transport & logistics | 2024 |