| Juniper Tree Services Company Limited | Real estate | 2026 |
| Jupp Best Plumbing and Heating Limited | Construction | 2015 |
| Just B U Ltd | Other services | 2024 |
| Just Motorcycles Limited | Wholesale & retail | 2011 |
| Justin M Roberts Limited | Health & social care | 2006 |
| JVS Autos Ltd | Hospitality | 2021 |
| JVS Property Maintenance Ltd | Real estate | 2025 |
| JW Creations Ltd | Professional & scientific | 2014 |
| Jwilson Trading Ltd | Wholesale & retail | 2024 |
| Jwxproperties Ltd | Real estate | 2025 |
| K & C Consultancy Services Limited | Information & communication | 2010 |
| K&L Barbering Ltd | Other services | 2019 |
| K&T Brothers Ltd | Transport & logistics | 2020 |
| K-Tech Automotive Limited | Wholesale & retail | 2010 |
| K. P. Project Contractors Limited | Construction | 2018 |
| K3 Consulting & Training Services Ltd | Professional & scientific | 2009 |
| K4 Architecture Ltd | Professional & scientific | 2026 |
| K90 Agriculture Ltd | Transport & logistics | 2026 |
| Kaambra Ltd | Wholesale & retail | 2024 |
| Kaashe Ltd | Wholesale & retail | 2014 |
| Kaashe Outlay Ltd | Real estate | 2024 |
| Kaashe Retail LLP | | 2015 |
| Kacee's Cleaning Ltd | Administrative & support | 2025 |
| Kade Health Ltd | Public administration | 2021 |
| Kadeep Properties Ltd | Real estate | 2021 |
| Kaeg Investments Ltd | Real estate | 2020 |
| Kaeg Top One Ltd | Construction | 2022 |
| Kage & Leaf Ltd | Manufacturing | 2026 |
| Kaindal Ltd | Construction | 2025 |
| Kaizen Development Ltd | Administrative & support | 1997 |
| Kala, the Arts | Education | 1998 |
| Kalabo Limited | Information & communication | 2016 |
| Kalin Woodcraft Ltd | Construction | 2026 |
| Kalstal Holdings Limited | Real estate | 2023 |
| Kalvinex Limited | Manufacturing | 2025 |
| Kamal Superstore Ltd | Wholesale & retail | 2018 |
| Kambala Solutions Limited | Information & communication | 2025 |
| Kamco Ventures Limited | Wholesale & retail | 2021 |
| Kapcha Limited | Administrative & support | 2014 |
| KAR Haulage Ltd | Transport & logistics | 2017 |
| Kara Holdings Ltd | Professional & scientific | 2015 |
| Karen De-Merist Consultancy Ltd | Professional & scientific | 2018 |
| Karma Gurkha Ltd | Hospitality | 2018 |
| Kashif Property Enterprise Private Limited | Real estate | 2016 |
| Kate-Lands Limited | Hospitality | 2017 |
| Katherine Morgan Marketing Ltd | Professional & scientific | 2017 |
| Kathryn Josey Limited | Wholesale & retail | 2024 |
| Katie Byard Psychology Limited | Health & social care | 2007 |
| KAY Linnell & Company Limited | Professional & scientific | 2010 |
| Kayan Ride Ltd | Transport & logistics | 2022 |
| Kaybee Fitting Solutions Ltd | Construction | 2025 |
| Kaybee Site Services (UK) Ltd | Transport & logistics | 2014 |
| Kaybee Storage Solutions Limited | Transport & logistics | 2022 |
| Kayenelle Limited | Information & communication | 2020 |
| KBB4U Limited | Manufacturing | 2012 |
| KBP Engineering Limited | Construction | 2010 |
| KBS Construction Ltd | Construction | 2012 |
| KCK Builders UK Ltd | Construction | 2024 |
| Kcube Solutions Ltd | Information & communication | 2021 |
| Keah Engineering Ltd. | Information & communication | 2016 |
| Keane's Keys Locksmiths of Basingstoke Limited | Construction | 2020 |
| Keel and Company Limited | Administrative & support | 1993 |
| Keemac Services Ltd | Professional & scientific | 2012 |
| Keep Insured With US (Kiwu) Limited | Financial services | 2023 |
| Keep IT Kool (KIK) Solutions Ltd | Extraterritorial | 2023 |
| Keimai Ltd | Wholesale & retail | 2024 |
| Keith Pegden Contracting Limited | Agriculture & fishing | 2019 |
| Keki's Guinea PIG Rescue CIC | Agriculture & fishing | 2025 |
| Keki’S Guinea Pigs Ltd | Agriculture & fishing | 2024 |
| Kellpen Limited | Construction | 2026 |
| Kelly & Mackay Ltd | Other services | 2016 |
| Kelton Wells Limited | Construction | 1980 |
| Kemp Consulting Ltd | Information & communication | 2011 |
| Kempshott Limited | Wholesale & retail | 2020 |
| Kemshall Design Limited | Professional & scientific | 1999 |
| Kent Payne Limited | Information & communication | 2016 |
| Kerbey's Kitchen Ltd | Health & social care | 2022 |
| KES Decisions Limited | Professional & scientific | 2018 |
| Kesa Tech Ltd | Wholesale & retail | 2018 |
| Kester Desmond & Associate Limited | Information & communication | 2019 |
| Kestrel’S Carpentry Ltd | Construction | 2024 |
| KEV Munday Ltd | Arts & recreation | 2021 |
| Key Computing Limited | Information & communication | 1993 |
| Key Geophysics Ltd | Professional & scientific | 2024 |
| Key Surgical Limited | Manufacturing | 1983 |
| Keycrest Property Ltd | Real estate | 2024 |
| Keyhome Survey Ltd | Real estate | 2025 |
| Keytech Systems Support Ltd | Manufacturing | 2017 |
| Kezia Initiatives (UK) Limited | Professional & scientific | 2008 |
| KF Victoria Ltd | Wholesale & retail | 2019 |
| Kgillar Therapy Limited | Health & social care | 2020 |
| KGS21 Properties Limited | Real estate | 2021 |
| Kidstrument Music Tuition Limited | Education | 2017 |
| Kikoi Connection CIC | Education | 2025 |
| Kilowatt Solutions Ltd | Extraterritorial | 2024 |
| Kimberley Phillips Ltd | Wholesale & retail | 2024 |
| Kinacom Consulting Ltd | Information & communication | 2016 |
| Kinetic K9S Limited | Professional & scientific | 2010 |
| King Charles Gate Residents Association Limited | Real estate | 2006 |
| Kings of Clearance Ltd | Water & waste | 2024 |