| Kdsb Limited | Other services | 2003 |
| KE Accounting Limited | Professional & scientific | 2014 |
| Keal Teamwear Ltd | Wholesale & retail | 2012 |
| Keats Engineering and Education Limited | Professional & scientific | 2020 |
| Kebab END Pizza Limited | Hospitality | 2020 |
| Kecs Cleaning Ltd | Administrative & support | 2025 |
| Keep UP Consultancy Ltd. | Professional & scientific | 2017 |
| Keepsake Cards & Gifts Limited | Wholesale & retail | 2012 |
| Keith Rennie Machinery (Holdings) Limited | Wholesale & retail | 2010 |
| Keith Rennie Machinery Limited | Wholesale & retail | 1986 |
| Keldfield Limited | Construction | 2012 |
| Keldspring Ltd | Wholesale & retail | 2023 |
| Kelly Signalling Ltd | Professional & scientific | 2022 |
| Kelly's Wharf Management Company Limited | Households | 2024 |
| Kelodum Ltd | Hospitality | 2019 |
| Kelso Farms Limited | Real estate | 2022 |
| Kember Living Ltd | Wholesale & retail | 2026 |
| Kemira Growhow Limited | Extraterritorial | 1982 |
| Kemset Limited | Wholesale & retail | 2021 |
| KEN Riley Property Ltd | Real estate | 2021 |
| KEN Spelman Books Limited | Wholesale & retail | 2012 |
| KEN Webster Builders Limited | Construction | 2016 |
| Kendal Blue Ltd | Professional & scientific | 2019 |
| Kendall Bailey Limited | Real estate | 2012 |
| Kendall Bailey Management Limited | Real estate | 2022 |
| Kendall Bailey Property Limited | Real estate | 2022 |
| Kendall Bailey SA Limited | Real estate | 2022 |
| Kendall Investments Ltd | Construction | 2013 |
| Kennedy & Maxwell Limited | Professional & scientific | 2015 |
| Kennedy Place (Ulverston) Management Company Limited | Households | 2016 |
| Kennington Consulting Ltd | Professional & scientific | 2013 |
| Kennington Property MGT Ltd | Real estate | 2025 |
| Kenrich Group Holdings Limited | Administrative & support | 1971 |
| Kensington Property Estat Ltd | Real estate | 2025 |
| Kenson Electrical Ltd | Construction | 2021 |
| Kenson GAS Ltd | Construction | 2019 |
| Kent 68 Ltd | Hospitality | 2019 |
| Kent Mistry Limited | Professional & scientific | 2023 |
| Kent Property Solutions Limited | Administrative & support | 2008 |
| Kent Worx Limited | Construction | 2017 |
| Kenton Contracting (Yorkshire) Limited | Extraterritorial | 1971 |
| Kenton Contractors (Yorkshire) Limited | Extraterritorial | 1970 |
| Kenton Homes (Builders) Limited | Extraterritorial | 1968 |
| Kenton Homes (Developments) Limited | Extraterritorial | 1967 |
| Kenton Homes (Estates) Limited | Extraterritorial | 1968 |
| Kentra Grain Systems Limited | Manufacturing | 1992 |
| Kentra Limited | Extraterritorial | 2013 |
| KERR2 Properties Ltd | Real estate | 2019 |
| KES International Management Ltd | Administrative & support | 2017 |
| Keshvari Properties Limited | Real estate | 2026 |
| Keskin Cleaning Ltd. | Administrative & support | 2026 |
| Kestrel Living Landscapes Ltd | Administrative & support | 2026 |
| Kestrel Rooflines Ltd | Construction | 2026 |
| KESTREL360 Limited | Education | 2015 |
| Kettle and Keyboard Ltd | Information & communication | 2013 |
| Kettlestring Limited | Hospitality | 2026 |
| Kevin GUY Limited | Wholesale & retail | 2002 |
| Kevin Hill Limited | Construction | 2002 |
| Kevin Linfoot Ltd | Professional & scientific | 2022 |
| Kevin Peschke Photography Ltd | Professional & scientific | 1979 |
| Kexby Barns Management Limited | Households | 2000 |
| Key Decision IT Limited | Information & communication | 2015 |
| Key Hospitality Ltd | Hospitality | 2026 |
| Key Tree Solutions Limited | Agriculture & fishing | 2023 |
| Keyfocus Limited | Information & communication | 1994 |
| Keyframe Homes Ltd | Real estate | 2019 |
| Keys to Comfort Properties Ltd | Other services | 2025 |
| Keystone Building Consultancy Limited | Professional & scientific | 2015 |
| Keystone Solutions Limited | Information & communication | 2007 |
| KF Bridal & Alterations Limited | Wholesale & retail | 2024 |
| KF Reporting Solutions Limited | Health & social care | 2019 |
| KFE Medical Ltd | Health & social care | 2024 |
| KGS Financial Consulting Limited | Professional & scientific | 2024 |
| KH Plastering Services Ltd | Construction | 2015 |
| KH York Limited | Professional & scientific | 2011 |
| Khaosan Road Limited | Hospitality | 2010 |
| Khoj Ltd | Wholesale & retail | 2024 |
| Kiasuperfoods Ltd | Manufacturing | 2025 |
| Kice Ltd | Hospitality | 2025 |
| Kickstone Technologies Limited | Information & communication | 2002 |
| Kielo Research UK Ltd | Professional & scientific | 2024 |
| Kieran Burns TM Ltd | Construction | 2025 |
| Kila Studios Limited | Professional & scientific | 2022 |
| Kildonan Homes Limited | Real estate | 2023 |
| Kilhey Court Hotels Limited | Hospitality | 1986 |
| Kiln Garth Management Company Limited | Real estate | 2022 |
| Kiln Logs Express Ltd | Agriculture & fishing | 2025 |
| Kilnwick Court Management Company Limited | Households | 1988 |
| Kilvo's Ltd | Financial services | 2017 |
| KIM Bowler & Co Limited | Professional & scientific | 2003 |
| Kimberley Dental Limited | Health & social care | 2024 |
| Kimberley Hall Events Limited | Hospitality | 2013 |
| Kimberley Louth Limited | Professional & scientific | 2015 |
| Kimberley Management Company Limited | Households | 1992 |
| Kimberlite Glass (York) Limited | Construction | 2014 |
| Kimbolton Limited | Real estate | 2015 |
| KIMI10 Ltd | Other services | 2015 |
| Kimmoisa Capital Management Ltd | Professional & scientific | 2016 |
| Kind Incentives Ltd | Administrative & support | 2023 |
| Kindlewoods CIC | Education | 2017 |