| Karen Mignon Communications Limited | Professional & scientific | 2021 |
| Karen Morris Memorial Trust | Health & social care | 2011 |
| Karen Turner Ltd | Health & social care | 2019 |
| Karikkustreetfood Limited | Hospitality | 2025 |
| Karlinger (UK) Limited | Professional & scientific | 2015 |
| Karmunity Builder Ltd | Real estate | 2023 |
| Karmunity Holdings Ltd | Real estate | 2025 |
| Karmunity Ltd | Agriculture & fishing | 2022 |
| Karmunity Services Ltd | Construction | 2024 |
| Karol Markota Ltd | Hospitality | 2024 |
| Karolis Spares OR Repairs Sales Ltd | Wholesale & retail | 2014 |
| Karrex Ltd | Real estate | 2018 |
| Karuiqi Watch Co., Ltd | Wholesale & retail | 2022 |
| Karukera Engineering Ltd | Manufacturing | 2026 |
| Karunya UK & EU Ltd | Construction | 2024 |
| Kasa Kulture Ltd | Wholesale & retail | 2025 |
| Kasalyst Limited | Hospitality | 2025 |
| Kashvi Novelty Ltd | Wholesale & retail | 2025 |
| Kaskin Properties Ltd | Real estate | 2024 |
| Kassir Trade Co., Ltd | Wholesale & retail | 2023 |
| Kate Fashion UK Ltd | Manufacturing | 2025 |
| Kate Fursdon Immigration Services Limited | Administrative & support | 2017 |
| Kate Grimley Evans Ltd | Professional & scientific | 2019 |
| Kate Hendry Ltd | Professional & scientific | 2018 |
| Kathland Limited | Real estate | 2026 |
| Kathryn Alderton Aesthetics Ltd | Health & social care | 2024 |
| Katie Cooper HR Ltd | Professional & scientific | 2026 |
| Katie Malik Property Solutions Ltd | Real estate | 2022 |
| Katie Underwood & Company Limited | Professional & scientific | 2020 |
| Katira Property Limited | Real estate | 2023 |
| Kaya Mehmet Ltd | Construction | 2024 |
| Kaya- Food Safety & Quality Consultancy Ltd | Administrative & support | 2019 |
| Kaylof Ltd | Information & communication | 2021 |
| Kays Plumbers Ltd | Construction | 2023 |
| Kaysnyder (UK) Co., Ltd | Wholesale & retail | 2026 |
| KAZ Contractors Limited | Construction | 2023 |
| Kaza RAW Property Ltd | Real estate | 2026 |
| KB CNC Machining Ltd | Manufacturing | 2025 |
| Kbex Trade Co., Ltd | Wholesale & retail | 2023 |
| KBF Trading Co., Ltd | Wholesale & retail | 2021 |
| KBH Flooring Limited | Construction | 2024 |
| Kbmi UK Limited | Information & communication | 2016 |
| KBN Services Limited | Information & communication | 2019 |
| KC Health Limited | Health & social care | 2022 |
| KCC Management (Sudbury) Limited | Households | 2023 |
| KCS Facilities Ltd | Other services | 2019 |
| KCS Plumbing Services Limited | Construction | 2005 |
| KCT Trade Ltd | Wholesale & retail | 2025 |
| KD Carbon Composites Limited | Manufacturing | 2015 |
| KDA Business Services Ltd | Education | 2024 |
| KDD3 Ltd | Professional & scientific | 2006 |
| KDH Transport Ltd | Transport & logistics | 2022 |
| KDM Cars Ltd | Wholesale & retail | 2026 |
| KE Hasc Limited | Administrative & support | 2023 |
| Keblelight Group Limited | Wholesale & retail | 2021 |
| Keeble Plumbing and Heating Ltd | Construction | 2021 |
| Keen Advice Limited | Professional & scientific | 2024 |
| Keen Design Ltd | Information & communication | 2023 |
| Keenstream Trading Limited | Wholesale & retail | 2020 |
| Keep IT Going Ltd | Professional & scientific | 2026 |
| Keephatch House Limited | Households | 2001 |
| Keerthana UK Ltd | Wholesale & retail | 2016 |
| Keith Collier Engineering Limited | Manufacturing | 2001 |
| Kellian Limited | Real estate | 2022 |
| Kellian Property LLP | | 2024 |
| Kelliher Renovations Limited | Construction | 2017 |
| Kelly Developments Limited | Construction | 2011 |
| Kelly Formwork Group Limited | Professional & scientific | 2012 |
| Kelly N Building Ltd | Construction | 2024 |
| Kelnetic Consulting Ltd | Professional & scientific | 2019 |
| Kelsey Laraine Aesthetics Limited | Other services | 2023 |
| Keltik CNC Limited | Manufacturing | 2023 |
| Kemflo Europe Limited | Other services | 2001 |
| Kemi Aircraft Repairs Ltd | Manufacturing | 2026 |
| Kempis Publications Ltd | Information & communication | 2024 |
| Kendall Developments Limited | Professional & scientific | 2018 |
| Kenea Ltd | Real estate | 2015 |
| Kenilworth Gray Ltd | Professional & scientific | 2023 |
| Kenley Group Ltd | Administrative & support | 2022 |
| Kennedy Car Services Limited | Wholesale & retail | 2003 |
| Kenny Productions Limited | Information & communication | 2012 |
| Kensal Court RTM Company Limited | Households | 2025 |
| Kenshi Limited | Information & communication | 2025 |
| Kentford Farms Ltd | Agriculture & fishing | 2022 |
| Kentings Financial Services Ltd | Financial services | 2021 |
| Kentings Will Writers Ltd | Financial services | 2015 |
| Kento Limited | Information & communication | 2022 |
| Kenwood Developments Ltd | Construction | 2014 |
| Kenza Cambridge Limited | Hospitality | 2023 |
| Kenzie's Coaches Limited | Transport & logistics | 1964 |
| Keo-Aero Ltd | Manufacturing | 2016 |
| Kerala Fresh Limited | Wholesale & retail | 2024 |
| Kerief Catering Limited | Administrative & support | 2017 |
| Kerifort Limited | Financial services | 2021 |
| Kerley & Co Limited | Agriculture & fishing | 2021 |
| Kerr Acoustic Ltd | Manufacturing | 2016 |
| KES Electrical (Cambridge) Limited | Administrative & support | 2016 |
| Keshrel Limited | Transport & logistics | 2010 |
| Kestrel Biodiversity Consulting Services Limited | Professional & scientific | 2025 |
| Kestrel Property and Land Ltd | Construction | 2010 |