| Karobar Restaurants Ltd | Hospitality | 2024 |
| Kasa Trading Ltd | Wholesale & retail | 2023 |
| Kasauli House Limited | Real estate | 2024 |
| Kashbooks Ltd | Other services | 2003 |
| Kashoptical Limited | Health & social care | 2022 |
| Kashta Ltd | Wholesale & retail | 2022 |
| Kassyanna Ltd | Transport & logistics | 2024 |
| Kate Create Ltd | Wholesale & retail | 2019 |
| Kate Grosvenor Coaching Limited | Education | 2018 |
| Kate Grosvenor Lifestyle Limited | Wholesale & retail | 2023 |
| Kate M-A Aesthetics Limited | Other services | 2025 |
| Kate's Kitchen (Maltby) Ltd | Hospitality | 2015 |
| Katherine Road Land Ltd | Extraterritorial | 2013 |
| Katikiti Tirivanhu 0373 Limited | Health & social care | 2014 |
| Katrina Cleary Associates Ltd | Professional & scientific | 2018 |
| Katy and Bones Ltd | Wholesale & retail | 2021 |
| KAY Family Holdings Limited | Construction | 2023 |
| KAY Spencer Healthcare Services Ltd | Health & social care | 2016 |
| Kayam Theatre Tents Ltd | Arts & recreation | 2001 |
| Kayss Limited | Other services | 2025 |
| KAZ Hair Style Limited | Other services | 2026 |
| KB Electrical Smart Home & Renewable Services Ltd | Construction | 2023 |
| KB Plastering (Maltby) Ltd | Construction | 2024 |
| Kbhood Ltd | Information & communication | 2026 |
| KBK Property Investments Ltd | Real estate | 2025 |
| KC Care & Social Activities Limited | Hospitality | 2018 |
| KC Lettings LLP | | 2013 |
| KC Training & Development Limited | Education | 2026 |
| Kcamel Solutions Ltd | Professional & scientific | 2025 |
| KCB Commercials Limited | Manufacturing | 2017 |
| Kccglw Ltd | Hospitality | 2025 |
| KCL Systems Limited | Construction | 2019 |
| KCM Trade Waste Limited | Water & waste | 2018 |
| KCM Waste Management Limited | Water & waste | 2012 |
| Kcpgames Ltd | Wholesale & retail | 2024 |
| KD & SON Precision Engineers Ltd | Manufacturing | 2014 |
| KD Car Body Repair & Spray Limited | Wholesale & retail | 2025 |
| KD Car Sales Ltd | Wholesale & retail | 2026 |
| KD Executive Ltd | Financial services | 2025 |
| KD Hospitality Limited | Wholesale & retail | 2025 |
| KD Medix Ltd | Health & social care | 2011 |
| KD Property Professionals Ltd | Construction | 2020 |
| Kdarshan Ltd | Information & communication | 2019 |
| KDR Construction Limited | Construction | 2003 |
| KDS Management Solutions Ltd | Administrative & support | 2010 |
| KEA Painting & Decorating Ltd | Construction | 2024 |
| Keata Media Ltd | Professional & scientific | 2024 |
| Kedar Consulting Ltd | Wholesale & retail | 2014 |
| Keely Houghton Advanced Skincare and Beauty Limited | Other services | 2017 |
| Keens Partitions Ltd | Construction | 2023 |
| Keep Construction Limited | Construction | 2024 |
| Keighley Financial Services Limited | Financial services | 2023 |
| Keith Levers Electrical Services Limited | Construction | 2021 |
| Keith's Quality Meats Limited | Hospitality | 2013 |
| Kelcorp Ltd | Wholesale & retail | 2021 |
| Keleigh Tech Services Ltd | Information & communication | 2013 |
| Kelham Deli & Kitchen Ltd | Hospitality | 2024 |
| Kelham Deli 2 Ltd | Hospitality | 2024 |
| Kelham Island Properties Ltd | Real estate | 2021 |
| Kelle G'S Limited | Real estate | 2008 |
| Kelly Associates (Consulting) Limited | Professional & scientific | 2024 |
| Kelly Associates (Surveyors) Limited | Professional & scientific | 2025 |
| Kelly Investments UK Limited | Real estate | 2005 |
| Kema Properties Limited | Real estate | 2007 |
| Kemper Campers Ltd | Wholesale & retail | 2024 |
| Kena Waste Management Holdings Ltd | Financial services | 2025 |
| Kena Waste Management Ltd | Water & waste | 2025 |
| Kendrive Ltd | Administrative & support | 2016 |
| Kensington & Earl Ltd | Construction | 2018 |
| Kent Lift Services Limited | Manufacturing | 2001 |
| Kenwood Tallulah Ltd | Households | 2014 |
| Keppels K&L Ltd | Hospitality | 2023 |
| Kese International Ltd | Manufacturing | 2022 |
| Keshavarz Limited | Financial services | 2025 |
| Kesse Auto Trading Ltd | Other services | 2022 |
| KET Theorem Ltd | Wholesale & retail | 2024 |
| KEV & Co Tattoos Ltd | Extraterritorial | 2025 |
| Kevin Fordham Ltd | Real estate | 2026 |
| Key Focus Support Limited | Health & social care | 2024 |
| Key Lettings South Yorkshire Limited | Real estate | 2022 |
| KEY2MOVE Estates Ltd | Real estate | 2015 |
| Keyrental Limited | Administrative & support | 2008 |
| Keys to Stay Ltd | Real estate | 2024 |
| Keystone Medicare Limited | Health & social care | 2023 |
| KH Chahal Properties Ltd | Real estate | 2023 |
| KH Medical Services Limited | Health & social care | 2015 |
| Khairy & Co Limited | Wholesale & retail | 2025 |
| Khairy Estates Limited | Real estate | 2026 |
| Khairy Property Holdings Limited | Real estate | 2021 |
| Khan Catering Rotherham Ltd | Hospitality | 2026 |
| Khan.Uanlr Limited | Wholesale & retail | 2024 |
| Khanfoodies Limited | Hospitality | 2025 |
| Khans Halal Butchers Ltd | Wholesale & retail | 2025 |
| Khans Khazana Limited | Hospitality | 2022 |
| KHR Chiropractic Limited | Health & social care | 2025 |
| Khyber Logistics Ltd | Transport & logistics | 2024 |
| Kian Green Building and Joinery Ltd | Construction | 2026 |
| Kiara Private Medical Limited | Health & social care | 2019 |
| Kids & Codes Ltd | Education | 2021 |
| Kieran's Catapult Bands Limited | Wholesale & retail | 2025 |