| K J Wall Limited | Manufacturing | 2015 |
| K Moxon Properties Limited | Real estate | 2022 |
| K S Harvey Limited | Information & communication | 2008 |
| K V K Ltd | Wholesale & retail | 2021 |
| K&J Organic Hair Care Ltd | Other services | 2020 |
| K&Sm Limited | Real estate | 2025 |
| K.D. Electrical Co. Limited | Construction | 1965 |
| K.V.Hartshorne (Chemists) Limited | Wholesale & retail | 1963 |
| K1 Consultants Limited | Professional & scientific | 2023 |
| K1 CUT Ltd | Other services | 2024 |
| K9 Consultancy Ltd | Professional & scientific | 2019 |
| Kaika Tech Limited | Wholesale & retail | 1989 |
| Kaizen Kreatives Ltd | Professional & scientific | 2025 |
| Kakkad Ltd | Professional & scientific | 2024 |
| Kandi Kingdom Ltd | Wholesale & retail | 2022 |
| Kandola (Telford) Ltd | Real estate | 2025 |
| Kandola Commercial Investments Ltd | Real estate | 2024 |
| Kandola Group Ltd | Financial services | 2024 |
| Kandola Residential Investments Ltd | Real estate | 2024 |
| Kang Investment Properties Ltd | Real estate | 2019 |
| Karen Handford Limited | Professional & scientific | 2013 |
| Kasper Gutman Ltd | Real estate | 2025 |
| Kass Wood Polishing Services Limited | Construction | 2023 |
| KB Plumbing & Drainage Ltd | Construction | 2024 |
| KCC Transport Ltd | Transport & logistics | 2025 |
| KCS Herr-Voss (UK) Limited | Professional & scientific | 2001 |
| KD Living Ltd | Hospitality | 2018 |
| KD7 Limited | Real estate | 2015 |
| KDE Property Limited | Real estate | 2020 |
| Kdlp Properties Limited | Real estate | 2021 |
| KEE Property Developments Ltd | Real estate | 2025 |
| Kees in Doors Ltd | Construction | 2026 |
| Kempton Installation Systems Limited | Construction | 2018 |
| Kempton Roofing Services Limited | Real estate | 2022 |
| Kendrick Sheet Metal Limited | Manufacturing | 1977 |
| Kenelm Consulting Ltd | Administrative & support | 2016 |
| Kensview Property Ltd | Real estate | 2024 |
| Kept Simple Ltd | Professional & scientific | 2016 |
| Kernohan Fire Safety Consultancy Limited | Public administration | 2010 |
| Kestrel & Hall Developments Ltd | Real estate | 2025 |
| Kestrel & Hall Group Ltd | Financial services | 2025 |
| Key to IT ALL Limited | Manufacturing | 2007 |
| Keys 16 Plus Independent Living Services Limited | Health & social care | 2005 |
| Keys 360 Limited | Professional & scientific | 2007 |
| Keys Accomplish BH Limited | Administrative & support | 2003 |
| Keys Accomplish CHR Limited | Health & social care | 2002 |
| Keys Accomplish FC Limited | Health & social care | 2002 |
| Keys Accomplish Group Limited | Financial services | 2017 |
| Keys Accomplish LH Limited | Health & social care | 2002 |
| Keys Accomplish MVL Limited | Health & social care | 2002 |
| Keys Accomplish OPO Limited | Health & social care | 2003 |
| Keys Accomplish TC Limited | Health & social care | 2016 |
| Keys Accomplish YLN Limited | Health & social care | 2016 |
| Keys Ace Limited | Health & social care | 2005 |
| Keys Acquico Limited | Financial services | 2022 |
| Keys Active 8 Care Limited | Health & social care | 2004 |
| Keys Bidco Limited | Financial services | 2017 |
| Keys BR Limited | Health & social care | 1999 |
| Keys Care Solutions Limited | Health & social care | 2003 |
| Keys Child Care (Holdings) Limited | Health & social care | 2001 |
| Keys Child Care Limited | Health & social care | 1994 |
| Keys CWC Limited | Health & social care | 2002 |
| Keys Cwch Limited | Professional & scientific | 2007 |
| Keys Direct Care Limited | Administrative & support | 2000 |
| Keys Education Limited | Health & social care | 1987 |
| Keys Educational Services Limited | Health & social care | 1999 |
| Keys Family Assessment Centre Limited | Health & social care | 2003 |
| Keys Group Holdings Limited | Financial services | 2021 |
| Keys Group Limited | Financial services | 2022 |
| Keys Group PCE (Holdings) Limited | Health & social care | 2014 |
| Keys Group PCE Community Support Services Limited | Real estate | 2003 |
| Keys Group PCE Realty Limited | Real estate | 2006 |
| Keys Group Progressive Care & Education Limited | Education | 1999 |
| Keys Group Progressive Education Limited | Health & social care | 2003 |
| Keys Group Properties Limited | Real estate | 2017 |
| Keys HH Limited | Administrative & support | 2002 |
| Keys Inclusion Pathways Limited | Health & social care | 2018 |
| Keys KIN Limited | Health & social care | 2015 |
| Keys Midco Limited | Financial services | 2017 |
| Keys Mipco Limited | Financial services | 2022 |
| Keys Nhcc Limited | Health & social care | 1996 |
| Keys NHG Limited | Real estate | 2002 |
| Keys PCE Limited | Financial services | 2017 |
| Keys QTC Limited | Health & social care | 1997 |
| Keys Services LLP | | 2026 |
| Keys Specialist Residential Children's Services Ltd | Health & social care | 2007 |
| Keys Stepping Stones Limited | Health & social care | 1999 |
| Keys Supported Accommodation Limited | Health & social care | 2006 |
| Keys Young People Limited | Health & social care | 1994 |
| Keystone Venture Property Ltd | Real estate | 2026 |
| Kfkc Medical Limited | Health & social care | 2016 |
| KG Surfacing Ltd | Construction | 2020 |
| Kgsh Retail Ltd | Wholesale & retail | 2021 |
| KH Foodie Ltd | Hospitality | 2024 |
| Khan's Surgical Limited | Health & social care | 2011 |
| Kheper Limited | Financial services | 2012 |
| Khfc ED Ltd | Education | 2016 |
| Kiad Infotech Ltd | Information & communication | 2024 |
| Kickology Ltd | Arts & recreation | 2026 |
| Kids Fashion Labels Ltd | Wholesale & retail | 2024 |