| KEO Aviation Ltd | Transport & logistics | 2017 |
| KEO Londn Ltd | Wholesale & retail | 2023 |
| KEO Properties Limited | Real estate | 2005 |
| Kerala Haven Ltd | Hospitality | 2024 |
| Kerdos Fellowship UK Ltd | Professional & scientific | 2022 |
| Kerfuffle Limited | Information & communication | 1998 |
| Kern Advisory Ltd | Professional & scientific | 2026 |
| Kernreed Limited | Information & communication | 1980 |
| Kernva Consulting Ltd | Professional & scientific | 2026 |
| Kersalotte Ltd | Construction | 2024 |
| Kersfield Developments (Clifton Park) Limited | Construction | 2017 |
| Kese Property Investments Ltd | Real estate | 2021 |
| Keshav Homes Limited | Real estate | 2020 |
| Keshav IT Consultancy Ltd | Information & communication | 2015 |
| Kestean Limited | Health & social care | 2019 |
| Kestrel Green Limited | Professional & scientific | 2010 |
| Ketamine 2 Recovery CIC | Education | 2025 |
| Ketas Property Limited | Real estate | 2024 |
| Keto Hana Limited | Manufacturing | 2017 |
| Ketraman Limited | Wholesale & retail | 2014 |
| Kettering Leisure Ltd | Administrative & support | 2014 |
| Kettkea Limited | Administrative & support | 2025 |
| Kevan Gough Consultants Limited | Administrative & support | 2003 |
| Kevangel Limited | Administrative & support | 2005 |
| KEW Collective Limited | Information & communication | 2026 |
| Key Cars (Milton Keynes) Limited | Transport & logistics | 2020 |
| Key Electrical Services Limited | Other services | 2017 |
| Key Investment Property Limited | Households | 2019 |
| Key Professional Solutions Ltd | Professional & scientific | 2020 |
| Key Solution Services Limited | Information & communication | 2008 |
| Keyblade Limited | Households | 1995 |
| Keyclimb Limited | Real estate | 2022 |
| Keyholder Lettings Management Limited | Real estate | 1994 |
| Keyholder Lettings and Management Services Limited | Real estate | 1999 |
| Keyhole Clinics Limited | Health & social care | 2010 |
| Keylab Automotive Ltd | Administrative & support | 2024 |
| Keyline Coaches Limited | Transport & logistics | 2023 |
| Keyne Developments Ltd | Construction | 2010 |
| Keyne HR Ltd | Professional & scientific | 2024 |
| Keyne MEN (UK) Limited | | 1988 |
| Keynes Automobiles Ltd | Wholesale & retail | 2026 |
| Keynes Care Services Limited | Public administration | 2017 |
| Keynes Construction MK Limited | Construction | 2024 |
| Keynes Roofing Centre Limited | Wholesale & retail | 1997 |
| Keynius UK Limited | Administrative & support | 2023 |
| Keynote Publications Limited | Arts & recreation | 2004 |
| Keypoint Education Ltd | Education | 2025 |
| Keypoint Global Services Ltd | Transport & logistics | 2024 |
| Keyshell Property Ltd | Real estate | 2022 |
| Keyshell Property Management Ltd | Construction | 2021 |
| Keyshell Property Services Ltd | Real estate | 2022 |
| Keysnake Ltd | Information & communication | 2023 |
| Keystone Developments (LG) Limited | Construction | 2001 |
| Keystone Global Compliance Ltd | Professional & scientific | 2026 |
| Keystone Leasehold Management Ltd | Households | 2011 |
| Keystone Mortgage Services Limited | Financial services | 2026 |
| Keystone Properties Group Ltd | Real estate | 2025 |
| Keystone Well Properties Limited | Real estate | 2026 |
| Keyville Limited | Information & communication | 2024 |
| Keyvservices Limited | Information & communication | 2021 |
| KFA Investment & Properties Limited | Other services | 2009 |
| KFB and Sons Ltd | Wholesale & retail | 2024 |
| KG Change Solutions Ltd | Administrative & support | 2017 |
| KG Model Management Limited | Other services | 2008 |
| KG Naturals Food Limited | Manufacturing | 2022 |
| KG Plumbing & Heating & Other Services Ltd | Construction | 2024 |
| KG Staffing Solutions Ltd | Administrative & support | 2026 |
| KG3 Properties Ltd | Real estate | 2020 |
| KGB Consultancy Services Ltd | Professional & scientific | 2022 |
| Kgdk Restaurants Limited | Hospitality | 2011 |
| Kgip Clapham Ltd | Hospitality | 2021 |
| KGR Aylesbury Ltd | Hospitality | 2021 |
| KGW Integrated Engineering Limited | Professional & scientific | 2019 |
| KH Tranport Ltd | Transport & logistics | 2025 |
| KHA UK Limited | Professional & scientific | 2006 |
| Khagdior Ltd | Construction | 2026 |
| Khamur Traders Ltd | Wholesale & retail | 2024 |
| Khan Adrs Ltd | Professional & scientific | 2026 |
| Kharis Group (UK) Ltd | Professional & scientific | 2024 |
| Kharis Health Ltd | Health & social care | 2023 |
| Khawarzami Islamic Consultation UK Limited | Education | 2015 |
| Khcn Limited | Other services | 2015 |
| Kheldar Consulting Limited | Professional & scientific | 2011 |
| Khim Limited | Real estate | 2015 |
| Khintastic Photography Limited | Professional & scientific | 2022 |
| KHL Prestigious Properties Limited | Real estate | 2024 |
| Khloe Dash Limited | Administrative & support | 2025 |
| Khozanda Care Limited | Real estate | 2022 |
| Khurana Phone Accessories Limited | Wholesale & retail | 2010 |
| Khyati Jewels Ltd | Manufacturing | 2024 |
| Khyberi Limited | Hospitality | 2025 |
| KI Lettings Ltd | Real estate | 2019 |
| Kian Trans Ltd | Transport & logistics | 2023 |
| Kiani London Ltd | Wholesale & retail | 2026 |
| Kibardin Limited | Wholesale & retail | 2013 |
| Kibeida Educational Ltd | Education | 2025 |
| KIC Service and Recruitment Ltd | Administrative & support | 2020 |
| Kick OFF Sports Centre Limited | Arts & recreation | 2013 |
| Kickbo Fitness Ltd | Arts & recreation | 2017 |
| Kicking Horse Ltd. | Wholesale & retail | 2013 |