| KA Management Solutions Limited | Real estate | 2012 |
| Kaava Limited | Manufacturing | 2024 |
| Kabanda Ltd | Wholesale & retail | 2025 |
| Kabeer Signature House Ltd | Wholesale & retail | 2025 |
| Kabrhel Group AG | Financial services | 2016 |
| Kahlon Investments Yorkshire Ltd | Real estate | 2022 |
| Kahlon Takeaway Limited | Hospitality | 2023 |
| Kaiju Martial Arts Ltd | Education | 2019 |
| Kairflo Limited | Wholesale & retail | 2004 |
| Kala Holdings Limited | Financial services | 2018 |
| Kalar Cameras and Installation Limited | Administrative & support | 2026 |
| Kalary Hand Car Wash Limited | Administrative & support | 2025 |
| Kam's Property Ltd | Real estate | 2024 |
| Kamach Logistics Ltd | Transport & logistics | 2025 |
| KAN of Steel Ltd | Wholesale & retail | 2014 |
| Kandoo Restaurant Ltd | Hospitality | 2022 |
| Kangaroo SEO Limited | Information & communication | 2015 |
| Kanvass Projects Limited | Construction | 2016 |
| Kapia Partners Limited | Administrative & support | 2020 |
| Kara Financial Consulting Limited | Professional & scientific | 2007 |
| Karen House Associates Limited | Professional & scientific | 2003 |
| Karito Limited | Health & social care | 2023 |
| Karizmah Limited | Wholesale & retail | 2013 |
| Karry 1 Campin Limited | Manufacturing | 2010 |
| Karsten Schmalfuss Consulting Ltd | Administrative & support | 2005 |
| Karwaan E ALI Masoom Limited | Administrative & support | 2025 |
| Kashmir Khan Ltd | Hospitality | 2026 |
| Kashmir Malik Ltd | Hospitality | 2024 |
| Kashmir Taste Ltd | Hospitality | 2014 |
| Kashmiri Aroma (Horbury) LLP | | 2024 |
| Kashmiri Posh Nosh Limited | Hospitality | 2021 |
| Kassh Properties Limited | Other services | 2023 |
| Kate Bailey Financial Planning Ltd | Professional & scientific | 2020 |
| Kate Siney Ltd | Information & communication | 2018 |
| Katko Electric UK Limited | Wholesale & retail | 2025 |
| Kato K-Media Limited | Arts & recreation | 2021 |
| Katta Fortune | Professional & scientific | 2017 |
| KAV Properties Ltd | Real estate | 2020 |
| Kavielon Limited | Wholesale & retail | 2020 |
| Kavielon Living Limited | Construction | 2021 |
| Kavielon Properties Limited | Real estate | 2020 |
| KAY Academy of Dance Ltd | Arts & recreation | 2026 |
| Kaye's Hotels Limited | Hospitality | 1990 |
| Kayfast Limited | Wholesale & retail | 2013 |
| Kaymac Consultancy Ltd | Construction | 2023 |
| KB Entertainment and Promotions Ltd | Hospitality | 2025 |
| KCB International Limited | Wholesale & retail | 2016 |
| KCK Decorators Limited | Construction | 2011 |
| KCL Storage and Distribution Ltd | Transport & logistics | 2026 |
| KD Refrigeration Ltd | Manufacturing | 2012 |
| KDB Joinery Ltd | Construction | 2026 |
| Kdmp Limited | Wholesale & retail | 2021 |
| KEA108 KST Ltd. | Professional & scientific | 2015 |
| KEA130 KST Ltd. | Professional & scientific | 2016 |
| Keaad Group Limited | Transport & logistics | 2025 |
| Keane Joinery Ltd | Manufacturing | 2022 |
| Kebay Ltd | Real estate | 2019 |
| Keelmine Limited | Real estate | 1985 |
| Keeping IT in the Family Ltd | Professional & scientific | 2014 |
| Keith Ridgeway Services Limited | Professional & scientific | 2020 |
| KEJ Medico-Legal Services Limited | Health & social care | 2019 |
| KEK Financial Services Limited | Financial services | 2022 |
| Keko Management Ltd | Real estate | 2022 |
| Kelgas Limited | Construction | 2007 |
| Kelly's Pet Services Ltd | Agriculture & fishing | 2021 |
| Kelport Limited | Wholesale & retail | 2016 |
| Kemu Studio Limited | Information & communication | 2013 |
| Kenclub Equipment Limited | Arts & recreation | 2021 |
| Kendon Engineering Limited | Information & communication | 2018 |
| Kenic Holdings Limited | Financial services | 2018 |
| Kenic Projects Limited | Construction | 2018 |
| Kennic Limited | Administrative & support | 2005 |
| Kensington Office Solutions (Leeds) Ltd | Construction | 2014 |
| Kentai Services UK Limited | Real estate | 2026 |
| Kepfel Ltd | Transport & logistics | 2020 |
| Kera Consultancy Ltd | Information & communication | 2018 |
| Kerb Killers Ltd | Wholesale & retail | 2025 |
| Kerf Interiors Limited | Construction | 2005 |
| Kerusco Visa Solutions UK Ltd | Professional & scientific | 2025 |
| Kerv Installs Limited | Professional & scientific | 2022 |
| Kerv Interiors Limited | Professional & scientific | 2021 |
| Kervah Limited | Information & communication | 2025 |
| KES Facilities Limited | Professional & scientific | 2014 |
| Kettle Black Ltd | Hospitality | 2024 |
| Kettle Black Manchester Ltd | Hospitality | 2025 |
| Ketz Letz Limited | Real estate | 2022 |
| Kev's Fisheries Ltd | Hospitality | 2022 |
| Kevin Amos Ltd | Construction | 2026 |
| Kevin Grice Ltd | Professional & scientific | 2014 |
| Kevora London Ltd | Health & social care | 2023 |
| Key & Co Properties Ltd | Real estate | 2015 |
| Key GRP Limited | Construction | 2004 |
| Key Page Media Limited | Professional & scientific | 2007 |
| Key Taping Interiors Limited | Construction | 2024 |
| Keyworth Rapid Manufacturing Limited | Manufacturing | 2010 |
| KF Exterior Group Ltd | Administrative & support | 2025 |
| KG Management Development & Coaching Limited | Professional & scientific | 2013 |
| KGP Design Limited | Professional & scientific | 2004 |
| KGS Development & Consulting Limited | Professional & scientific | 2013 |
| KH Designs and Landscaping Ltd | Administrative & support | 2022 |