| Karlmogga Ltd | Construction | 2025 |
| Karni Limited | Construction | 2010 |
| Karonscraftiness Ltd | Wholesale & retail | 2022 |
| Kart Dynamics Ltd | Wholesale & retail | 2020 |
| Karting Events Ltd | Arts & recreation | 2019 |
| Karvion Ltd | Wholesale & retail | 2025 |
| Kasavupuranam Ltd | Wholesale & retail | 2025 |
| Kash Shah Accountants UK Ltd | Professional & scientific | 2021 |
| Kashmir Convenient Foods Limited | Wholesale & retail | 2020 |
| Kashmir Farm Ltd | Agriculture & fishing | 2020 |
| Kashmir International Food Store Limited | Wholesale & retail | 2016 |
| Kashmiri Chaska Limited | Hospitality | 2019 |
| Kasoa Growth Ltd | Real estate | 2021 |
| Kass Classics N Autos Ltd | Wholesale & retail | 2022 |
| Kate and Dawn Limited | Other services | 2011 |
| Kathmandu Momo Ltd | Hospitality | 2026 |
| Kathryn Barr Estate Agents Ltd | Real estate | 2025 |
| Katie's House Childcare Ltd | Health & social care | 2023 |
| Kator Ltd | Households | 2025 |
| Kavi Retail Limited | Wholesale & retail | 2023 |
| KAY Consultants Limited | Professional & scientific | 2016 |
| KC & the Sunshine Shop Limited | Other services | 2012 |
| KCA Cars Limited | Real estate | 2010 |
| KCE Property Solutions Ltd | Real estate | 2020 |
| KCE Solutions Ltd | Professional & scientific | 2017 |
| KD Mortgages Limited | Financial services | 2025 |
| KD Pharma UK Limited | Manufacturing | 2011 |
| KDN Carpentry and Joinery Limited | Construction | 2016 |
| Kebrico (Holdings) Limited | Financial services | 2019 |
| Kebrico Limited | Wholesale & retail | 1978 |
| Kedlestone Cars Limited | Wholesale & retail | 2019 |
| Kedlestone Enterprises Ltd | Wholesale & retail | 2023 |
| Keegan Ventures Limited | Financial services | 2025 |
| Keelan Cairnes Ltd | Construction | 2025 |
| Keenan Substation Solutions Ltd | Professional & scientific | 2015 |
| Kellrod Limited | Real estate | 2019 |
| Kelso Kirby Limited | Information & communication | 2025 |
| Kelt Properties Limited | Construction | 2009 |
| Kemtel Health Care Limited | Health & social care | 2014 |
| Kenburn Cleaning Services Ltd | Households | 2011 |
| Kencorp Developments Ltd | Real estate | 2020 |
| Kencorp Scaffolding Ltd | Construction | 2018 |
| Kenden Security Limited | Administrative & support | 2005 |
| Kent Autorecycle Limited | Water & waste | 2026 |
| KER Site Services Ltd | Construction | 2024 |
| Kerry Lloyd Fisher Limited | Other services | 2014 |
| Kerry Lockwood - in Detail Ltd | Professional & scientific | 2022 |
| Kerry's Kitchen Ltd | Hospitality | 2015 |
| Kettlebell Movement Ltd | Arts & recreation | 2026 |
| Kevin and Sandra Holtby Ltd | Agriculture & fishing | 2017 |
| Kevin Liddle Building Services Ltd | Construction | 2016 |
| Kevin Mahoney Mortgages Ltd | Financial services | 2024 |
| Kevin N Svensson Limited | Wholesale & retail | 2025 |
| Key Skills Consultancy & Training Limited | Education | 2023 |
| Keystone Brick Ltd | Construction | 2024 |
| Keystone Property Resolutions Ltd | Real estate | 2025 |
| KEZ MAC Ltd | Public administration | 2026 |
| KFD Motors Limited | Wholesale & retail | 2024 |
| KFG Engineering Services Limited | Construction | 2015 |
| KG DIY Construction Ltd | Construction | 2025 |
| KGS67 Ltd | Professional & scientific | 2020 |
| KH Uddin Ltd | Health & social care | 2013 |
| Khalsa Homes Ltd | Real estate | 2023 |
| Khan Catering Services Limited | Hospitality | 2018 |
| Khan Indian Takeaway Ltd | Hospitality | 2020 |
| Khanam Events Limited | Hospitality | 2025 |
| KHM Civils Ltd | Construction | 2020 |
| Khurco Limited | Construction | 2025 |
| Khushal Management Limited | Real estate | 2022 |
| Khyber CK Ltd | Hospitality | 2024 |
| KHZ Properties Ltd | Real estate | 2020 |
| Kicci Ltd | Real estate | 2026 |
| Kiddtech E&I Services Ltd | Professional & scientific | 2026 |
| Kidsons Ltd | Other services | 2013 |
| Kidz Konnekt | Other services | 2009 |
| Kiezer Engineering Ltd | Construction | 2015 |
| Kighir LAM Ltd | Professional & scientific | 2016 |
| Kill Line Limited | Other services | 2020 |
| Kill Miami Ltd | Information & communication | 2020 |
| Kindreds Haunted Emporium Limited | Wholesale & retail | 2026 |
| Kingdom NE Ltd | Wholesale & retail | 2024 |
| Kinkyeverydays Ltd | Wholesale & retail | 2021 |
| Kiran Diya Ltd | Professional & scientific | 2010 |
| Kirkdale Bespoke Ltd | Manufacturing | 2026 |
| Kirtley Crane Engineering and Inspection Services Ltd | Manufacturing | 2020 |
| Kirton Haulage Limited | Transport & logistics | 2011 |
| Kirwan Marine Ltd | Transport & logistics | 2023 |
| KIS Scaffolding Ltd | Construction | 2019 |
| Kita's Alpha Kitchen Limited | Hospitality | 2025 |
| Kitchen & Bathroom Studio Ltd | Wholesale & retail | 2013 |
| Kiwi Management NE Ltd | Administrative & support | 2019 |
| Kiya Fashion Limited | Manufacturing | 2023 |
| Kiyanni Ltd | Information & communication | 2024 |
| KJ Access Limited | Mining & quarrying | 2019 |
| KJ Fulfilment Ltd | Wholesale & retail | 2026 |
| KJC Cars Ltd | Wholesale & retail | 2025 |
| KJJ Estates Ltd | Hospitality | 2026 |
| KJN Engineering Limited | Construction | 2023 |
| KJR Bars Ltd | Hospitality | 2018 |
| KJR Trading Limited | Wholesale & retail | 2023 |