| JTI Solutions Limited | Information & communication | 2017 |
| JTO Consultants Limited | Professional & scientific | 2023 |
| Judgeys Ltd | Hospitality | 2025 |
| Jummy Care Limited | Extraterritorial | 2014 |
| Jump Giants Heathrow Limited | Arts & recreation | 2015 |
| Jump Giants Holdings Limited | Financial services | 2015 |
| Jump Giants Loughborough Limited | Arts & recreation | 2016 |
| Jump Giants Newcastle Limited | Arts & recreation | 2017 |
| JUN Sky Tara Ltd | Hospitality | 2019 |
| Junella Care Limited | Health & social care | 2024 |
| Jupiter's Products and Services Ltd | Wholesale & retail | 2025 |
| Jupre Limited | Hospitality | 2021 |
| Jusna Blackwater Spice Limited | Hospitality | 2025 |
| Just Call US Ltd | Information & communication | 2020 |
| Just Design & Construction Limited | Construction | 2017 |
| Just Drive America Ltd | Administrative & support | 2021 |
| Just Mots (Hawley Lane) Ltd | Wholesale & retail | 2023 |
| Justask Cleaning Services Ltd | Administrative & support | 2018 |
| Justbeadhd Ltd | Health & social care | 2023 |
| Justo Building Services Ltd | Construction | 2025 |
| Juttla Ltd | Construction | 1996 |
| Juttla Services Ltd | Other services | 2025 |
| JV88 Limited | Professional & scientific | 2018 |
| JW Administration Services Ltd | Administrative & support | 2021 |
| JW Plus Limited | Professional & scientific | 2017 |
| JW Sourcing Limited | Professional & scientific | 2011 |
| JXW Limited | Health & social care | 2001 |
| JYA Limited | Professional & scientific | 2016 |
| JYK Investments Ltd | Real estate | 2024 |
| K & J Construction and Civil Engineering Limited | Construction | 2016 |
| K & J Property Management Limited | Real estate | 2021 |
| K & M Herd Limited | Arts & recreation | 2014 |
| K & S (Surrey) Limited | Construction | 2015 |
| K & S Family Ltd | Other services | 2023 |
| K Construction & Building Ltd | Construction | 2016 |
| K M Flow Screed Ltd | Construction | 2020 |
| K&D Transport Ltd | Transport & logistics | 2022 |
| K&H Investments Ltd | Real estate | 2024 |
| K&P H20 Limited | Administrative & support | 2007 |
| K&T Consulting Ltd | Information & communication | 2023 |
| K-Prime Solutions Ltd | Professional & scientific | 2025 |
| K. Gawley Electrical Services Limited | Construction | 2015 |
| K.A. Rylance Limited | Construction | 2013 |
| K.B.Q. Ltd. | Construction | 2000 |
| K1 Properties Rentals Limited | Real estate | 2021 |
| K9 Korner Ltd | Other services | 2024 |
| Kaboot Ltd | Wholesale & retail | 2025 |
| Kade PS Ltd | Construction | 2021 |
| Kadison Construction Ltd | Construction | 2015 |
| Kadydee Ltd | Extraterritorial | 2023 |
| Kahout Brothers Ltd | Transport & logistics | 2022 |
| Kaimax Limited | Health & social care | 2007 |
| Kalbhairav Limited | Wholesale & retail | 2025 |
| Kallo Foods Limited | Wholesale & retail | 1994 |
| Kamil Sznicer Limited | Construction | 2026 |
| Kamiya Developments Limited | Real estate | 2014 |
| Kangaroo (World Cargo) Limited | Transport & logistics | 1999 |
| Kangaroo Customs Services Limited | Professional & scientific | 2002 |
| Kaniko Ltd | Wholesale & retail | 2020 |
| Kapoor Logistics Ltd | Transport & logistics | 2025 |
| Kapx Media Consult Limited | Professional & scientific | 2022 |
| Karabayir Ltd | Hospitality | 2017 |
| Karachi Biryani Limited | Hospitality | 2020 |
| Karma Bavaria Title Limited | Professional & scientific | 2015 |
| Karma Residence Title Limited | Professional & scientific | 2025 |
| Karussell Media Limited | Administrative & support | 2023 |
| Kashmir Court Management Company Limited | Households | 1996 |
| Kate Thomas Floral Design Limited | Wholesale & retail | 2019 |
| Katesix Marketing Limited | Information & communication | 2013 |
| Katie Tunn Fine Art Limited | Arts & recreation | 2011 |
| Kavanagh Engineering Services Limited | Professional & scientific | 2014 |
| KAY9 Services Limited | Other services | 2022 |
| Kaylen Kash Lettings Ltd | Real estate | 2025 |
| KBO Consultancy Ltd | Professional & scientific | 2021 |
| KBO Fire & Security Limited | Administrative & support | 2008 |
| KBO Holdings UK Limited | Financial services | 2021 |
| KC People Development Ltd | Professional & scientific | 2018 |
| KC Rotating Machinery Consultancy Ltd | Professional & scientific | 2025 |
| Kcrs Management Limited | Professional & scientific | 2018 |
| KDG Commercial Limited | Wholesale & retail | 2024 |
| Keaver Drive (Frimley) Management Company Limited | Households | 2011 |
| Kebla Ltd | Manufacturing | 2025 |
| Kebur Concrete Products Limited | Extraterritorial | 2008 |
| Kebur Garden Materials LLP | | 2026 |
| Kebur Stone Imports Ltd | Administrative & support | 2016 |
| Keen Holdings & Investments Ltd | Financial services | 2025 |
| Keen IT Solutions Limited | Information & communication | 2005 |
| Keen Property Limited | Real estate | 2025 |
| Keen Solutions Limited | Information & communication | 2024 |
| Keen Spaces Limited | Real estate | 2015 |
| Keen Voip Limited | Information & communication | 2016 |
| Keil Homes Limited | Real estate | 2016 |
| Keko Personnel Limited | Administrative & support | 2022 |
| Kelmon Limited | Administrative & support | 2022 |
| Kennard Aviation (Camberley)Limited | Other services | 1971 |
| Kennedy News and Media Limited | Information & communication | 2018 |
| Kennet Heights Limited | Households | 1998 |
| Kenneth Jones Property Management Limited | Real estate | 2022 |
| Kent Dairy Company Ltd | Administrative & support | 2010 |
| Kentley Homes Ltd | Construction | 2016 |