| Kama Steel Trading Limited | Wholesale & retail | 2016 |
| Kaminska Consulting Ltd | Professional & scientific | 2015 |
| Kaminski Limited | Education | 1996 |
| Kamsi Global Ltd | Wholesale & retail | 2022 |
| Kanesbury Care (Aranlaw House Care Home) Limited | Health & social care | 2003 |
| Kanesbury Care (Eagles Mount Green Community) Limited | Health & social care | 2016 |
| Kanesbury Care (Kingsman House Care Home) Limited | Health & social care | 2018 |
| Kanesbury Care (Regency Manor Care Home) Limited | Health & social care | 2013 |
| Kanesbury Care (Seabourne House Care Home) Limited | Health & social care | 2021 |
| Kanesbury Care Aranlaw House Limited | Health & social care | 2020 |
| Kanesbury Care Branksome Park Limited | Health & social care | 2014 |
| Kanesbury Care Eagles Mount Limited | Health & social care | 2020 |
| Kanesbury Care Group Limited | Financial services | 2004 |
| Kanesbury Care Holdings Limited | Financial services | 2022 |
| Kanesbury Care Investments Limited | Financial services | 2016 |
| Kanesbury Care Kingsman House Limited | Health & social care | 2022 |
| Kanesbury Care Regency Manor Limited | Health & social care | 2020 |
| Kanesbury Care Seabourne House Limited | Health & social care | 2021 |
| Kanesbury Construction Limited | Construction | 2013 |
| Kangaroo Co. Ltd | Professional & scientific | 2014 |
| Kanjo Technologies Limited | Information & communication | 2020 |
| Kaos Beds Limited | Wholesale & retail | 2006 |
| Kappa Europe Limited | Other services | 2023 |
| Kappeta Properties Ltd | Real estate | 2022 |
| Kara Ball Advanced Skincare & Aesthetics Ltd | Other services | 2023 |
| Karadag Ltd | Other services | 2019 |
| Karaham Limited | Hospitality | 2005 |
| Karaoke Rooms Ltd | Hospitality | 2017 |
| Kardifish Limited | Hospitality | 2018 |
| Karen Johnson & Co Ltd | Education | 2021 |
| Karol Boguta Ltd | Transport & logistics | 2019 |
| Kartrans Logistics Limited | Transport & logistics | 2015 |
| Kasa Entertainment Limited | Hospitality | 2013 |
| Kasbah Club Limited | Arts & recreation | 2010 |
| Katana Consultancy Ltd | Professional & scientific | 2018 |
| Katerose (Poole) Management Company Limited | Real estate | 2016 |
| Katherine Senior Ltd | Arts & recreation | 2024 |
| Kathie Kozlak Ltd | Other services | 2026 |
| Kathmandu (U.K.) Limited | Wholesale & retail | 2003 |
| Kathryn Mcghie Ltd | Real estate | 2025 |
| Kathy DE Beer Limited | Professional & scientific | 2006 |
| Katie DE Souza Ltd | Information & communication | 2018 |
| Katie Jane Home Limited | Wholesale & retail | 2013 |
| Katie Jane Limited | Wholesale & retail | 2013 |
| Katie Thomas Design Limited | Professional & scientific | 2017 |
| Katl Limited | Manufacturing | 2024 |
| Katrina Kennedy AHP Limited | Education | 2023 |
| Katrinacame Ltd | Health & social care | 2023 |
| Kavai Precious Metals Limited | Manufacturing | 2021 |
| Kavkaz Ltd | Manufacturing | 2025 |
| Kawsar Pizza Limited | Hospitality | 2023 |
| Kaya Management Ltd | Real estate | 2023 |
| Kayla (Dorset) Limited | Hospitality | 2010 |
| Kaz's Craft Concept Ltd | Construction | 2021 |
| Kazoku Sushi Ltd | Hospitality | 2019 |
| KB Pools Limited | Construction | 2003 |
| KBG Hair Ltd | Other services | 2023 |
| KBO Products Ltd | Wholesale & retail | 2015 |
| Kbrillot Limited | Manufacturing | 2023 |
| KC (SP6) RTM Company Limited | Households | 2022 |
| KC Dialysis Limited | Health & social care | 2018 |
| KC Doors Limited | Manufacturing | 2018 |
| KC Live Group Ltd | Hospitality | 2025 |
| KCH Investment Ltd | Real estate | 2025 |
| KCL Interiors Limited | Construction | 2020 |
| KCM Autosales Limited | Wholesale & retail | 2020 |
| KD Carpentry and Building Limited | Construction | 2020 |
| KDG Consult Ltd | Manufacturing | 2022 |
| KDS Trading Ltd | Hospitality | 2020 |
| Kdsp Properties Ltd | Real estate | 2025 |
| KDZ Catering Ltd | Hospitality | 2025 |
| Kebba's Barbers Limited | Other services | 2018 |
| Kebeya and IVY Ltd | Wholesale & retail | 2026 |
| Kechi Health Systems Ltd | Information & communication | 2026 |
| Kedeal Limited | Professional & scientific | 2021 |
| Keep Art IT Ltd | Construction | 2021 |
| Keep IT Sweet Confectionery Ltd | Wholesale & retail | 2013 |
| Keeping Studio Limited | Information & communication | 2013 |
| Keith Mersh Building & Property Repair Service Limited | Construction | 2015 |
| Kekeculture Ltd | Other services | 2025 |
| Kelfam Investments Ltd | Real estate | 2016 |
| Kello Ltd | Information & communication | 2021 |
| Kelvin House Freehold Limited | Households | 2014 |
| Kema International Timber Ltd | Wholesale & retail | 2022 |
| Kemipinky Healthcare Ltd | Health & social care | 2022 |
| Kemp Commercial Vehicle Recruitment Ltd | Administrative & support | 2019 |
| Kemp EKO Talent Ltd | Administrative & support | 2025 |
| Kemp Recruitment Limited | Administrative & support | 2010 |
| Kempire Limited | Real estate | 2022 |
| Kempton Court Limited | Households | 2022 |
| KEN Parke Planning Consultants Limited | Professional & scientific | 2003 |
| KEN Sheldrake Limited | Wholesale & retail | 2009 |
| Kenan Private Chef Ltd | Hospitality | 2020 |
| Kenexa Consultants Limited | Professional & scientific | 2016 |
| Kennedysoko Ltd | Health & social care | 2019 |
| Kennington Services Limited | Households | 1999 |
| Kennisapp Ltd | Information & communication | 2025 |
| Kensington Court Freehold Management Company (Bournemouth) Limited | Households | 2017 |
| Kensington Court Management Company Limited | Households | 1978 |
| Kensington Mint Limited | Wholesale & retail | 2021 |