| Khcs Consultants Limited | Professional & scientific | 1999 |
| Khcs Secretaries Limited | Extraterritorial | 2002 |
| Kica Brothers Ltd | Wholesale & retail | 2026 |
| Kidd & Co (Herts) Limited | Construction | 2024 |
| Kidocare Ltd | Information & communication | 2025 |
| Kieran James Ltd | Real estate | 2022 |
| Kiki Fünf Ltd | Wholesale & retail | 2021 |
| Kilners Grange (Tongham) Management Company Limited | Households | 2019 |
| Kims Equestrian Limited | Agriculture & fishing | 2025 |
| Kinanah Investment Ltd | Real estate | 2021 |
| Kinder-Janes Engineers Limited | Professional & scientific | 1957 |
| Kindred Controls Limited | Construction | 2024 |
| Kinetic Search Solutions Limited | Administrative & support | 2023 |
| King Estate Agents Ltd | Real estate | 2011 |
| King of the Road Publishing Limited | Information & communication | 2015 |
| Kinga Healthcare Ltd | Health & social care | 2019 |
| Kingdom Build Group Ltd | Transport & logistics | 2019 |
| Kingdon Investigation Training Ltd | Education | 2018 |
| Kingfisher Court (Dunston Riverside) Management Company Ltd | Households | 2005 |
| Kingfisher Green (Cranbrook) Management Co Limited | Households | 2022 |
| Kingley Gate Management Limited | Construction | 2014 |
| Kings CAP Ltd | Professional & scientific | 2016 |
| Kings Court (HP3 9AX) RTM Company Limited | Households | 2022 |
| Kings Development (Tring) Limited | Construction | 2018 |
| Kings FX Limited | Administrative & support | 2024 |
| Kings Langley Bowls Club CIC | Arts & recreation | 2018 |
| Kings Langley Cars Limited | Administrative & support | 2017 |
| Kings Meadow Residents Management Company Limited | Households | 2018 |
| Kingshill Agri Limited | Wholesale & retail | 2023 |
| Kingshott Media Ltd | Professional & scientific | 2020 |
| Kingsland Park Management Company Limited | Households | 2020 |
| Kingsley Village (Nantwich) Management Company Limited | Households | 2002 |
| Kingslowe Decorating Services Limited | Construction | 2007 |
| Kingsmere Park (West Parley) Management Company Limited | Households | 2023 |
| Kingston LEY Residents' Association Limited | Households | 2002 |
| Kingsvale Property Ltd | Real estate | 2024 |
| Kingswood Court (West END Lane) Limited | Households | 1994 |
| Kingswood Vans Ltd | Administrative & support | 2011 |
| Kinsella Property Group Limited | Construction | 2025 |
| Kintara Holdings Ltd | Education | 2025 |
| Kirriemuir Limited | Manufacturing | 1967 |
| Kirst Berry Fitness Ltd | Health & social care | 2025 |
| Kirton Business Services Limited | Professional & scientific | 2011 |
| Kisa Design Limited | Administrative & support | 2014 |
| Kiskirine Events Limited | Administrative & support | 2012 |
| Kiss Services Ltd | Construction | 2023 |
| KIT Miles Limited | Manufacturing | 2013 |
| KIT Property Ltd | Real estate | 2022 |
| Kite View Estates Limited | Households | 2019 |
| Kitka Limited | Professional & scientific | 2010 |
| Kjmlaw Ltd | Other services | 2015 |
| Kjp-Electrical Services Limited | Construction | 2020 |
| Kjwfx Limited | Arts & recreation | 2012 |
| KKR Lucco Ltd | Education | 2022 |
| Kkrl Limited | Information & communication | 2014 |
| KKS Pharma Enterprise Ltd | Real estate | 2017 |
| Klasyka Porcelany I Bizuterii Ltd | Wholesale & retail | 2025 |
| Klgot Ltd | Health & social care | 2022 |
| KLH Communications Ltd | Information & communication | 2021 |
| Kline Motors Ltd | Wholesale & retail | 2020 |
| KM Shipping Limited | Transport & logistics | 2024 |
| Kmis 2024 Limited | Professional & scientific | 2024 |
| KMJ Consultants Limited | Professional & scientific | 2020 |
| KMK Distributions Limited | Transport & logistics | 2009 |
| Kmlandscapingandbuilding Services Ltd | Agriculture & fishing | 2026 |
| Kmlandscapingandsons Ltd | Administrative & support | 2026 |
| Kmm/Landscape/Solutions Ltd | Construction | 2019 |
| Knightlow Park Management Company Limited | Households | 2017 |
| Knightsbridge Accountants Ltd | Professional & scientific | 2023 |
| Knoture Ltd | Construction | 2022 |
| Know Your Latitude Ltd | Manufacturing | 2026 |
| Knowmoore Construction Ltd | Construction | 2025 |
| Knox Cropper LLP | | 2018 |
| KO Holdco Ltd | Financial services | 2024 |
| Kodak Alaris Holdings Limited | Financial services | 2013 |
| Kodak Alaris International Limited | Manufacturing | 2013 |
| Kodak Alaris Limited | Manufacturing | 2013 |
| Kofee Ltd | Wholesale & retail | 2021 |
| KOH Education Ltd | Education | 2025 |
| Komplete Genius Ltd | Education | 2015 |
| Konas Team Ltd | Construction | 2015 |
| Kondody Enterprise Ltd | Other services | 2025 |
| Kondody Traders Ltd | Wholesale & retail | 2024 |
| Kookaburra Shutters & Blinds Ltd | Administrative & support | 2022 |
| Kool Cars Ltd | Wholesale & retail | 2026 |
| Koop Aesthetics and Beauty Ltd | Other services | 2023 |
| KORIS365 Central Holdings Limited | Information & communication | 2009 |
| KORIS365 UK Limited | Information & communication | 2011 |
| KOS Stone Ltd | Manufacturing | 2025 |
| Kosrp Ltd | Administrative & support | 2025 |
| KP Life Sciences Limited | Financial services | 2021 |
| KPD Home Improvements Limited | Construction | 2020 |
| KPQ Ltd | Information & communication | 2023 |
| Kraken Surveying Limited | Professional & scientific | 2025 |
| Kris Driving Company (UK) Limited | Professional & scientific | 2013 |
| KRP Holdings Ltd | Professional & scientific | 2024 |
| KS Frank Ltd. | Other services | 2015 |
| Ksait Ltd | Wholesale & retail | 2026 |
| KSK Logistics Ltd | Transport & logistics | 2017 |
| KT Construction & Consultancy Ltd | Wholesale & retail | 2024 |