| KMA Consulting Limited | Extraterritorial | 1998 |
| KMA Grocery Ltd | Wholesale & retail | 2026 |
| Knight Line Ltd | Transport & logistics | 2025 |
| Knightworth Construction Ltd | Construction | 2021 |
| Knitted Ltd | Wholesale & retail | 2025 |
| Knott Close Management Company Limited | Real estate | 2007 |
| Knotts of Tempsford Ltd | Agriculture & fishing | 2023 |
| Knowyourpoker Ltd | Information & communication | 2026 |
| Kompakt Ltd | Wholesale & retail | 2022 |
| Konti Limited | Hospitality | 2019 |
| Korab Builders Ltd | Construction | 2020 |
| Kothiya UK Limited | Hospitality | 2024 |
| Kothu HUT Limited | Hospitality | 2020 |
| KP Flooring Limited | Construction | 2026 |
| KPD Plumbing and Heating Ltd | Other services | 2017 |
| Kr&J Professonal Healthcare Ltd | Health & social care | 2023 |
| Krak Life Ltd | Manufacturing | 2024 |
| Kriger Ltd | Construction | 2019 |
| Kris Cieslak Art Limited | Arts & recreation | 2022 |
| Krishna Homes Limited | Real estate | 2026 |
| KRM Lettings Ltd | Real estate | 2022 |
| Kross Generation Ltd | Wholesale & retail | 2019 |
| Krossa Limited | Health & social care | 2022 |
| KS Railway Miniatures Ltd | Arts & recreation | 2023 |
| Ksquare Pharma Limited | Wholesale & retail | 2024 |
| Ksss Homes Ltd | Real estate | 2024 |
| KTH Services Limited | Construction | 2005 |
| Kuca Consulting Ltd | Real estate | 2019 |
| Kuiiek Investments Limited | Real estate | 2024 |
| Kuldeep Singh Construction Ltd | Construction | 2022 |
| Kulture Circle CIC | Education | 2026 |
| Kumar & Kumar Ltd | Health & social care | 2016 |
| Kutting UK Limited | Manufacturing | 1993 |
| KV Associates Limited | Professional & scientific | 2022 |
| KVT Garages Limited | Professional & scientific | 2005 |
| Kyaiawire Limited | Wholesale & retail | 2010 |
| Kyberwatch Ltd | Information & communication | 2026 |
| Kyle Smart Associates Limited | Professional & scientific | 2006 |
| Kynn Tech Limited | Information & communication | 2022 |
| Kyza Property Ltd | Real estate | 2023 |
| L & J Automotive Limited | Wholesale & retail | 2025 |
| L a Morris & SON Limited | Construction | 2006 |
| L R Gawley Limited | Wholesale & retail | 2013 |
| L S M Security (UK) Ltd | Administrative & support | 2023 |
| L T Energy Services Limited | Construction | 2022 |
| L.Wilkinson Services Ltd | Construction | 2024 |
| LA Bella Calabria Ltd | Hospitality | 2020 |
| LA Novela Cakes Ltd | Manufacturing | 2021 |
| La-Maracci Limited | Other services | 2016 |
| Laaga Limited | Wholesale & retail | 2019 |
| Laah Entertainment Limited | Information & communication | 2012 |
| Labels and Till Rolls Ltd | Wholesale & retail | 2021 |
| Lacris Ltd | Real estate | 2024 |
| Lactus Ltd | Construction | 2015 |
| LAD Consulting Ltd | Professional & scientific | 2023 |
| LAG Sales Progression Ltd | Real estate | 2025 |
| Lais Properties Ltd | Real estate | 2015 |
| Laizza UK Limited | Wholesale & retail | 2017 |
| Lake Way Limited | Hospitality | 2025 |
| Lakefield Properties Group Limited | Real estate | 2026 |
| Lakefiled Properties Group Limited | Real estate | 2026 |
| Lakeville Limited | Real estate | 2025 |
| Lala Bazar Limited | Wholesale & retail | 2014 |
| Lalsco Innovations Ltd | Professional & scientific | 2022 |
| Laluna Lettings Ltd | Real estate | 2024 |
| Lambert Wealth Ltd | Administrative & support | 2017 |
| Lamingo Limited | Hospitality | 2017 |
| Lancello Ltd | Construction | 2018 |
| Landchief Limited | Real estate | 1971 |
| Landlord Tax & Accountancy Services Ltd | Extraterritorial | 2012 |
| Landscape Consultancy Limited | Professional & scientific | 2008 |
| Landsdown Property Portfolio Limited | Real estate | 1999 |
| Landsworth Limited | Real estate | 2011 |
| Lane Right Ltd | Public administration | 2024 |
| Lapp Logistic Ltd | Transport & logistics | 2021 |
| Lara Launderette Limited | Other services | 2024 |
| Laserhaus Ltd | Other services | 2026 |
| Lasotamotors Limited | Wholesale & retail | 2022 |
| Last Chance Films Limited | Information & communication | 2007 |
| Last Chance Interactive Ltd | Information & communication | 2018 |
| Latitude IP Ltd | Professional & scientific | 2026 |
| Latte Café Ruya Ltd | Hospitality | 2024 |
| Launchstream Limited | Extraterritorial | 2004 |
| Laura Catering Company Limited | Hospitality | 2017 |
| Laura Nissen Consultancy Ltd | Professional & scientific | 2021 |
| Laurel Median Investments Limited | Real estate | 2024 |
| Laus Engineering Limited | Professional & scientific | 2022 |
| Laus Innovations Limited | Professional & scientific | 2024 |
| Lavender Express Limited | Hospitality | 2022 |
| Lavender Holdings Limited | Financial services | 2023 |
| Lavendon Hospitality Limited | Hospitality | 2014 |
| Lavio Ltd | Wholesale & retail | 2024 |
| Law Property Lettings Limited | Real estate | 2021 |
| Lawn View Consultancy Limited | Professional & scientific | 2024 |
| Lawn View Limited | Real estate | 2020 |
| Lawsonsmetering Ltd | Energy | 2026 |
| Lazar Catalin Limited | Construction | 2015 |
| LB Comfort Solutions Ltd | Construction | 2019 |
| Lbond Developments Limited | Administrative & support | 2025 |
| LD Feathers Limited | Real estate | 2024 |