| Knight Design (Sheffield) Limited | Construction | 2015 |
| Knight Residences Limited | Real estate | 2024 |
| Knights of Limited | Information & communication | 2017 |
| Knightsbridge Builders Ltd | Construction | 2025 |
| Knightsbrook Estates Ltd | Real estate | 2023 |
| Knightsbrook Leisure Ltd | Hospitality | 2024 |
| Knightsmove Estates Ltd | Real estate | 2020 |
| Kniveton (UK) Limited | Water & waste | 1998 |
| Knockout Holdings Ltd | Financial services | 2019 |
| Knot.Db Ltd | Real estate | 2024 |
| Knowhow Education Ltd | Professional & scientific | 2021 |
| Knowle Court Flats Limited | Households | 2013 |
| Knowledge FLO Limited | Professional & scientific | 2012 |
| Knowledge Integration Ltd | Information & communication | 1999 |
| Knowledge Network Konsulting Limited | Information & communication | 2005 |
| Knowledgytech Ltd | Information & communication | 2025 |
| Knowles Warwick Academy Services Limited | Information & communication | 1999 |
| Knowles Warwick Audit Services Limited | Professional & scientific | 2001 |
| Knowles Warwick Group Limited | Professional & scientific | 2004 |
| Knowles Warwick Limited | Professional & scientific | 1991 |
| Knowleslg Limited | Professional & scientific | 2025 |
| Knox Games Limited | Manufacturing | 2025 |
| Ko's Catering Limited | Hospitality | 2009 |
| Koala Legal Ltd | Information & communication | 2025 |
| Koala Nursery Ltd | Other services | 2018 |
| Koala Tech Ltd | Information & communication | 2025 |
| Koba Swim Ltd | Wholesale & retail | 2022 |
| Koban Food Ltd | Wholesale & retail | 2026 |
| Kodakoda Limited | Professional & scientific | 2021 |
| Koefficient Ltd | Professional & scientific | 2018 |
| Koen Digital Limited | Information & communication | 2017 |
| Koetje Transport Ltd | Transport & logistics | 2025 |
| Koinonia Academies Trust | Education | 2013 |
| Koinonia Consultancy Limited | Information & communication | 2024 |
| Koinonia Ventures Ltd | Hospitality | 2024 |
| Kojo & LEE Limited | Administrative & support | 2013 |
| Koko Nails Spa Ltd | Other services | 2025 |
| Koksall Limited | Hospitality | 2021 |
| Kolab Agency Limited | Professional & scientific | 2025 |
| Kolkata Express Ltd | Hospitality | 2025 |
| Kollective Coffee and Kitchen Ltd | Hospitality | 2022 |
| Kollective Holdings Ltd | Professional & scientific | 2023 |
| Kollective Kitchen Ltd | Hospitality | 2018 |
| Kollider Incubator Limited | Professional & scientific | 2020 |
| Kollider Nominees Limited | Financial services | 2018 |
| KOM Advisors Ltd | Administrative & support | 2010 |
| Komar KRD Limited | Hospitality | 2023 |
| Komatik Ltd | Construction | 2018 |
| Komfy Sleep Ltd | Manufacturing | 2022 |
| Komkan Food Limited | Hospitality | 2025 |
| Komodo Logistics Ltd | Transport & logistics | 2015 |
| Komorebi Trade Limited | Wholesale & retail | 2025 |
| Komposites Limited | Manufacturing | 2004 |
| Kompton Limited | Manufacturing | 2017 |
| Koncept Investments Limited | Real estate | 2021 |
| Koncept Maintenance Support Ltd | Construction | 2020 |
| Kondo Interiors Ltd | Manufacturing | 2019 |
| Konobo Controls Ltd | Professional & scientific | 2025 |
| Konrad Textile Limited | Manufacturing | 2025 |
| Konrad Travel Ltd | Transport & logistics | 2025 |
| Kontou Estates Limited | Real estate | 2012 |
| Kontou Properties Limited | Real estate | 2014 |
| Kopa Coffee Limited | Hospitality | 2025 |
| Kopi and Chai Ltd | Hospitality | 2020 |
| Kopi Stores Ltd | Hospitality | 2022 |
| Kora UK Limited | Arts & recreation | 2008 |
| Korab Building Services Limited | Construction | 2023 |
| Korab Properties (JA) Limited | Real estate | 2024 |
| Kore Box Ltd | Wholesale & retail | 2019 |
| Kore Compliance Ltd | Professional & scientific | 2019 |
| Kormag Inductive Components Ltd | Professional & scientific | 2024 |
| Korra Limited | Real estate | 2025 |
| Kostal UK Limited | Wholesale & retail | 1990 |
| KOT Management Ltd | Real estate | 2024 |
| Kotsanai Social Care Ltd | Health & social care | 2023 |
| Kove Limited | Wholesale & retail | 2025 |
| Kowisnogughs Consulting Ltd | Information & communication | 2024 |
| Koya Food Ltd | Hospitality | 2026 |
| Koya Hospitality Services Limited | Administrative & support | 2026 |
| Koyu London Limited | Wholesale & retail | 2024 |
| Koyu Wagyu Ltd | Wholesale & retail | 2024 |
| KP Auto DD Ltd | Wholesale & retail | 2020 |
| KP Beds Limited | Wholesale & retail | 2014 |
| KP Construction Group Ltd | Construction | 2023 |
| KP Electrical and Building Limited | Construction | 2025 |
| KP Property and Lettings Limited | Real estate | 2022 |
| KP Renovations Ltd | Construction | 2021 |
| KP Tidy Ltd | Administrative & support | 2023 |
| Kpasso Ltd | Hospitality | 2023 |
| Kpfc Social Ltd | Hospitality | 2021 |
| Kpmd IT Solutions Limited | Information & communication | 1995 |
| Kpnews Limited | Wholesale & retail | 2016 |
| KPS Mechanical Ltd | Construction | 2006 |
| Kptan Limited | Wholesale & retail | 2025 |
| KQ Partners Ltd | Real estate | 2015 |
| KR Invest GR Limited | Real estate | 2020 |
| KRA POW LDN Ltd | Hospitality | 2016 |
| KRA Sports Limited | Financial services | 2024 |
| Kraftathlet Ltd. | Wholesale & retail | 2025 |
| Krankenhaus Festival Limited | Arts & recreation | 2003 |