| KCS Hair Limited | Other services | 2018 |
| KD Property (Shrewton) Ltd | Construction | 2023 |
| KD Shepherding Limited | Agriculture & fishing | 2024 |
| Kd's Canine Services Ltd | Other services | 2025 |
| KDC Paving and Landscapes Limited | Administrative & support | 2018 |
| Keen Capital Properties Limited | Administrative & support | 2015 |
| Keep a Beat Global Ltd | Education | 2016 |
| Keero Properties Limited | Financial services | 2026 |
| Keith Bartlett and Associates Limited | Professional & scientific | 2014 |
| Keith Ridley Mechanical Services Ltd | Professional & scientific | 2023 |
| Kellaway Properties Limited | Real estate | 2021 |
| Kelly Wilson Interiors Limited | Other services | 2015 |
| Kelsey Road (RTM) Property Management Limited | Households | 2014 |
| Kemileyon Ltd | Professional & scientific | 2013 |
| Kemmotors Ltd | Wholesale & retail | 2024 |
| Kempthorne Management Company Limited | Households | 1999 |
| Kendal Mews Management Company Limited | Real estate | 1986 |
| Kennedy Properties (Salisbury) Ltd | Real estate | 2021 |
| Kennington A&L Ltd | Administrative & support | 2020 |
| Kennington Creative Group Ltd | Information & communication | 2011 |
| Kennington Creatives Ltd | Administrative & support | 2020 |
| Kennon & Caitlin Ltd | Real estate | 2025 |
| Kennylands Place (Sonning Common) Management Company Limited | Households | 2022 |
| Kensons Farm Limited | Agriculture & fishing | 2019 |
| Kent Associates Ltd | Information & communication | 2011 |
| Kents Oak Limited | Construction | 1987 |
| Kesken Limited | Health & social care | 2017 |
| Kevin Heath Decorators Ltd | Construction | 2003 |
| Key Accounting Services (Salisbury) Ltd | Professional & scientific | 2004 |
| Key EPC Ltd | Construction | 2023 |
| Keyline Press Limited | Administrative & support | 1999 |
| Keysley Developments Limited | Construction | 2025 |
| Keysley Limited | Agriculture & fishing | 2003 |
| Keysley Store Limited | Agriculture & fishing | 2008 |
| Keystone Cards Limited | Manufacturing | 2016 |
| Keysun Limited | Real estate | 1986 |
| KGG (Wandsworth) Residents Management Company Limited | Households | 2024 |
| KH Holdings (South West) Ltd | Financial services | 2025 |
| Khalsa Logistics Limited | Transport & logistics | 2018 |
| KHT Properties Limited | Households | 2021 |
| Kichaka Limited | Construction | 2016 |
| Kickstand Marketing Ltd. | Professional & scientific | 2014 |
| Kidzlovefit Limited | Arts & recreation | 2015 |
| Kilkenny Associates Limited | Professional & scientific | 2016 |
| Kilokilo Services Ltd | Health & social care | 2023 |
| Kimpton Livery Ltd | Agriculture & fishing | 2009 |
| KIN HO Photography Ltd | Professional & scientific | 2013 |
| Kinected Systems Limited | Financial services | 2024 |
| Kinfauns Road (Block Q) Management Company Limited | Households | 1992 |
| King Edward Place Management Company (Nuneaton NO. 1) Limited | Households | 2005 |
| King Edward Place Management Company (Nuneaton NO. 2) Limited | Households | 2005 |
| Kingdom Barbell Ltd | Arts & recreation | 2020 |
| Kingfisher Court Carterton Management Limited | Households | 2008 |
| Kingfisher Ecology Limited | Professional & scientific | 2017 |
| Kingsbridge Fields Management Company Limited | Households | 2013 |
| Kingsbrook (Moss Grove) Management Company Limited | Households | 2004 |
| Kingsbury Practice Limited | Professional & scientific | 2010 |
| Kingscastle Developments Limited | Construction | 2020 |
| Kingscastle Limited | Real estate | 1977 |
| Kingscastle Management Limited | Real estate | 2020 |
| Kingscroft (Developments) Ltd | Construction | 2017 |
| Kingsdown Farm Ltd | Agriculture & fishing | 2007 |
| Kingsettle Stud Limited | Hospitality | 2020 |
| Kingsreach (Slough) Management Company Limited | Households | 2014 |
| Kingsway Design Limited | Professional & scientific | 2021 |
| Kingswood (High Wycombe) Management Company Limited | Households | 2015 |
| Kink Motorcycles Ltd | Hospitality | 2023 |
| Kinn Properties Ltd | Professional & scientific | 2019 |
| Kinriel Technologies Limited | Information & communication | 2023 |
| Kinyerezi Care Limited | Health & social care | 2014 |
| Kipling House Management RTM Company Limited | Households | 2007 |
| Kippie Holdings Limited | Financial services | 2026 |
| Kippie Pubs Limited | Hospitality | 2026 |
| Kippie Trading Limited | Financial services | 2026 |
| Kirat Yakthung Chumlung UK Limited | Health & social care | 2011 |
| Kish & AB Ltd | Real estate | 2025 |
| Kismet Photography & Print Ltd | Manufacturing | 2015 |
| Kiss the Fish Limited | Professional & scientific | 2009 |
| KIT Fielding Ltd | Information & communication | 2018 |
| Kitagawa Europe Limited | Wholesale & retail | 1982 |
| Kitbrix Ltd | Wholesale & retail | 2013 |
| Kitchen Garden Botanicals Ltd | Wholesale & retail | 2020 |
| Kitchen Sprays Limited | Construction | 2021 |
| Kitley Place Management Company Limited | Households | 2012 |
| Kiwifruit Property Limited | Extraterritorial | 2005 |
| KJ EAR WAX Removal Ltd | Health & social care | 2024 |
| KJM Intellectual Property Limited | Professional & scientific | 2019 |
| KK Oriental Limited | Hospitality | 2022 |
| Kk's Restaurant Limited | Hospitality | 2017 |
| KKC Film Ltd | Administrative & support | 2026 |
| KKS Dinner Limited | Hospitality | 2025 |
| Kkwjs Limited | Administrative & support | 2019 |
| Klick Magazine Ltd | Information & communication | 2023 |
| Kludo Bars Limited | Hospitality | 2026 |
| Kludo Holdings Limited | Real estate | 2025 |
| Kmhf Residential Ltd | Real estate | 2025 |
| Knapp Hollow Management Limited | Real estate | 2013 |
| KNH Designs Ltd | Wholesale & retail | 2012 |
| Knight Print Management Ltd | Information & communication | 2013 |
| Knight Tanker Services Limited | Wholesale & retail | 2026 |