| K a Sulka Ltd | Health & social care | 2022 |
| K a T Interiors Ltd | Construction | 2015 |
| K Brown Property Group Ltd | Financial services | 2018 |
| K Brown Property Investments Ltd | Real estate | 2018 |
| K Freight U.K. Limited | Information & communication | 1999 |
| K J K Landscape Contracts Limited | Administrative & support | 2015 |
| K M J Haulage Limited | Professional & scientific | 2005 |
| K R Johnson Accountancy Services Limited | Professional & scientific | 1997 |
| K Selvester Ltd | Real estate | 2025 |
| K&Ab Ltd | Transport & logistics | 2025 |
| K&C Engineering Services Limited | Professional & scientific | 2024 |
| K&K Creative House Limited | Real estate | 2025 |
| K.E.G. Signs Ltd | Manufacturing | 2011 |
| K.W.S. Services Limited | Professional & scientific | 1997 |
| K9 Couture Grooming Ltd | Other services | 2012 |
| K9 Ricks Ltd | Other services | 2026 |
| KAC Mechanical Services Ltd | Manufacturing | 2019 |
| Kailash Vision Estates Ltd | Real estate | 2021 |
| Kairos Collective Ltd | Administrative & support | 2025 |
| Kakou Surf Limited | Wholesale & retail | 2025 |
| KAM Create Limited | Manufacturing | 2024 |
| Kapm Property Development Limited | Real estate | 2017 |
| Kapm Property Management Limited | Real estate | 2022 |
| Kapm Services Limited | Construction | 2016 |
| Karakas Tamworth Ltd | Hospitality | 2023 |
| Karina Automotive Ltd | Wholesale & retail | 2026 |
| Karton Media Ltd | Information & communication | 2019 |
| Kasa Sourcing Limited | Wholesale & retail | 2000 |
| Kassidy Consulting Ltd | Professional & scientific | 2023 |
| Katemedia UK Ltd | Information & communication | 2021 |
| Kates Cleans Ltd | Administrative & support | 2023 |
| Kayeco Limited | Wholesale & retail | 2001 |
| KB Cars (Milton Keynes) Limited | Transport & logistics | 2017 |
| KB Floorplans Ltd | Professional & scientific | 2023 |
| KB Properties Midlands Limited | Households | 2015 |
| KBP Property Services Ltd | Construction | 2022 |
| Kchg Limited | Wholesale & retail | 2022 |
| KCT Logistics Ltd | Transport & logistics | 2004 |
| KDS Builders and Roofing Ltd | Construction | 2018 |
| Keddleston Ltd | Professional & scientific | 2008 |
| KEELEX450 Limited | Manufacturing | 2022 |
| Keely Holdings Limited | Professional & scientific | 1997 |
| Keith Paul Taylor Ltd | Professional & scientific | 2026 |
| Kelika Limited | Professional & scientific | 2003 |
| Kelly M Properties Limited | Real estate | 2024 |
| Kelmoore Electrical Limited | Construction | 2013 |
| Keloko Collections Ltd | Financial services | 2024 |
| Kemi Rhema Homes Ltd | Real estate | 2024 |
| Kendal Aesthetics Ltd | Health & social care | 2022 |
| Kensington Four Limited | Professional & scientific | 2025 |
| Kent Conservation Limited | Professional & scientific | 2013 |
| Kenton Manor Properties Limited | Real estate | 2014 |
| KEO Communications Ltd | Information & communication | 2015 |
| KEP Print Group Limited | Manufacturing | 1981 |
| Kep(Rp) Limited | Manufacturing | 2000 |
| Keresforth Consultants Limited | Professional & scientific | 2026 |
| Kerr Stuart Locomotives Limited | Extraterritorial | 2004 |
| Kerr, Stuart & Company Ltd | Arts & recreation | 1998 |
| Kershaw Design and Build Limited | Construction | 2021 |
| KET Property Investments Ltd | Real estate | 2013 |
| Kettlebrook Estates Limited | Households | 1997 |
| Kevin Patel Creative Ltd | Professional & scientific | 2020 |
| Key Healthcare Staffing Limited | Administrative & support | 2022 |
| Key Systems Holdings Limited | Information & communication | 2022 |
| Key Systems OUT of Home Software Limited | Information & communication | 2007 |
| Keystar Homes Limited | Real estate | 2013 |
| Keyway Motors Ltd | Wholesale & retail | 2025 |
| Kfig Limited | Arts & recreation | 2006 |
| KG Recruitment Solutions Limited | Administrative & support | 2025 |
| KG Tilford Properties Limited | Real estate | 2022 |
| KGS Groundworks & Property Maintenance Ltd | Construction | 2020 |
| Khalfe Consulting Ltd | Administrative & support | 2016 |
| Khiroya Properties Limited | Real estate | 2026 |
| KID Engineering Limited | Administrative & support | 2014 |
| Kidz Health Ltd | Health & social care | 2024 |
| Kidz Klub Limited | Wholesale & retail | 2003 |
| Kieran Parsonage Rail Limited | Construction | 2019 |
| KIF Transport Ltd | Transport & logistics | 2015 |
| Kiinglandshops Limited | Wholesale & retail | 2025 |
| KIJ Limited | Professional & scientific | 2003 |
| Kilcrona Ltd | Health & social care | 2004 |
| KIM Revill Limited | Arts & recreation | 2017 |
| Kimbermills Limited | Financial services | 2016 |
| Kimlyn Products Limited | Manufacturing | 1961 |
| Kims Nail and Beauty(Tamworth) Ltd | Other services | 2024 |
| KIN67 Ltd | Hospitality | 2026 |
| Kind Lights Studio Limited | Professional & scientific | 2025 |
| Kinetic Investments Limited | Real estate | 2014 |
| Kinetic Vision Ltd | Transport & logistics | 2010 |
| Kingfisher Carpets Limited | Construction | 1988 |
| Kingsbury 1ST Pre-School Ltd | Education | 2013 |
| Kingsbury Garage Limited | Wholesale & retail | 2006 |
| Kingsbury Kids Club Limited | Health & social care | 2019 |
| Kingsbury Lawn Care Limited | Administrative & support | 2017 |
| Kingsbury Pallets Holdings Limited | Financial services | 2024 |
| Kingsbury Pallets Limited | Manufacturing | 1996 |
| Kingsbury Tankers Limited | Transport & logistics | 2014 |
| Kingsbury Village Cafe Ltd | Hospitality | 2016 |
| Kingscote Properties Ltd | Real estate | 2026 |
| Kingsley Realtors Limited | Real estate | 2023 |