| Kobo Solutions Ltd | Information & communication | 2021 |
| Koda & Sons Construction Ltd | Construction | 2024 |
| Koda & Sons Electrical Services Ltd | Construction | 2022 |
| Kodanti Limited | Health & social care | 2022 |
| Kofstel Engineering Limited | Construction | 2020 |
| Kognitive Solutions Limited | Information & communication | 2016 |
| Kola Steel Ltd | Construction | 2018 |
| Konsol & Associates UK Ltd | Professional & scientific | 2009 |
| Koorgen Ltd | Manufacturing | 2023 |
| Koppert Installations Ltd | Administrative & support | 2017 |
| Koppert Survey Services Ltd | Professional & scientific | 2026 |
| Kora Alexander Limited | Real estate | 2018 |
| Korb Homes Limited | Real estate | 2024 |
| Koremark Property Ltd Ltd | Real estate | 2023 |
| Koshie Services Limited | Health & social care | 2015 |
| Kosmos Constructions Ltd | Construction | 2021 |
| Kososhee Limited | Wholesale & retail | 2008 |
| Kosty Ltd | Wholesale & retail | 2013 |
| Kotu Ltd. | Education | 2023 |
| KOY Medicare Limited | Health & social care | 2025 |
| KP Decorating and Spraying Services Ltd | Construction | 2024 |
| KP Design and Build Limited | Administrative & support | 2017 |
| KP Hair Limited | Other services | 2018 |
| KPL Shareholders Limited | Real estate | 2015 |
| KR Staffing Solutions Ltd | Administrative & support | 2024 |
| KR Tech Limited | Wholesale & retail | 2015 |
| KRE Services Ltd | Construction | 2024 |
| Kreer Ltd | Arts & recreation | 2017 |
| Krellym Fortitude Ltd | Real estate | 2020 |
| Kris Landscape Limited | Administrative & support | 2023 |
| Kristal Medicare Limited | Health & social care | 2022 |
| Kristina Properties Limited | Real estate | 2025 |
| KS Fire Protection Ltd | Other services | 2018 |
| KSR Drylining Ltd | Construction | 2016 |
| KSS Automotive Ltd | Wholesale & retail | 2023 |
| KSV Group Investments Ltd | Real estate | 2024 |
| KT Cleaning & Hygiene Ltd | Administrative & support | 2024 |
| KTM World Foods Ltd | Wholesale & retail | 2024 |
| KTS (Essex) Holdings Ltd | Administrative & support | 2022 |
| Kube Construction Ltd | Construction | 2009 |
| Kubel Ltd | Construction | 2022 |
| Kulture LDN Group Ltd | Professional & scientific | 2019 |
| Kumar & Swasti Group Ltd | Health & social care | 2026 |
| Kundi Africa Holdings Limited | Financial services | 2025 |
| Kushlosh Limited | Information & communication | 2015 |
| Kutchenhaus Cockfosters Limited | Wholesale & retail | 2021 |
| Kuwe Properties Ltd | Professional & scientific | 2018 |
| Kwasi Mensah Limited | Transport & logistics | 2019 |
| Kwikdtg Ltd | Manufacturing | 2021 |
| Kyiv-London Auto and Logistics Ltd | Wholesale & retail | 2026 |
| Kynzi Ltd | Administrative & support | 2024 |
| Kyrie Limited | Health & social care | 2019 |
| Kyte IT Ltd | Information & communication | 2018 |
| Káyòmi Ltd | Wholesale & retail | 2023 |
| L & a Catering Company Ltd | Hospitality | 2021 |
| L & a the Phoenix PUB Ltd | Hospitality | 2022 |
| L & J Outdoor Services Limited | Administrative & support | 2025 |
| L & T School Limited | Education | 2023 |
| L Harlow Ltd | Hospitality | 2025 |
| L Holness Limited | Construction | 2025 |
| L K Cladding Limited | Construction | 2020 |
| L Willitt Trading Ltd | Financial services | 2025 |
| L&A Partnership Limited | Hospitality | 2014 |
| L&J Solutions Ltd | Construction | 2020 |
| L&R Property Ventures Ltd | Real estate | 2025 |
| L'Estime Limited | Other services | 2015 |
| L.A Fire, Electrical and Security Limited | Construction | 2019 |
| L.A.C. Harlow Ltd | Wholesale & retail | 2019 |
| L.A.C. Hoddesdon Limited | Hospitality | 2020 |
| L.I.S (UK) II Limited | Other services | 2018 |
| L.I.S. Management (U.K.) Ltd | Other services | 2022 |
| L.T. Noble Limited | Construction | 2007 |
| L00PED Clothing Repairs Limited | Extraterritorial | 2023 |
| LA Carpentry & Developments Ltd | Construction | 2020 |
| LA Electrical & Building Services Ltd. | Construction | 2018 |
| LA Maison DE Caint Ltd | Wholesale & retail | 2026 |
| LA Marmite Ltd | Other services | 2016 |
| LA Rinascita Ltd | Wholesale & retail | 2022 |
| LAB Design & Print Limited | Professional & scientific | 2015 |
| Labish Commercials Ltd | Information & communication | 2014 |
| Labish Consultancy Ltd | Information & communication | 2018 |
| Labish Services Limited | Real estate | 2020 |
| Laced UP Ltd | Wholesale & retail | 2025 |
| Ladricon Solutions Limited | Health & social care | 2025 |
| Ladybird Voice Solutions Limited | Information & communication | 2015 |
| Lael Services Limited | Administrative & support | 2017 |
| Lagetro Techmeg Services Ltd | Information & communication | 2019 |
| Lago MAX Limited | Real estate | 2025 |
| LAH Molehill Ltd | Construction | 2022 |
| LAK Medical Services Ltd | Health & social care | 2026 |
| Laknik Consult Limited | Professional & scientific | 2023 |
| Lala Productions Limited | Arts & recreation | 2024 |
| LAM Referrals & Consultancy Ltd | Professional & scientific | 2025 |
| Lamidun Consulting Limited | Information & communication | 2019 |
| Lamin-X UK Limited | Wholesale & retail | 2024 |
| Lammy T Logistics Ltd | Transport & logistics | 2024 |
| Lamya Construction Limited | Construction | 2005 |
| Lancaster Gate West (Hendon) Management Company Limited | Households | 1989 |
| Lancelyn Court Flats (NO. 2) Limited | Households | 1984 |
| Landsmart Limited | Agriculture & fishing | 2003 |