| Khyber (U.K) Ltd | Wholesale & retail | 2018 |
| KIA Ahmed Limited | Construction | 2022 |
| Kiannia Limited | Health & social care | 2022 |
| Kiassic Beauty Ltd | Other services | 2025 |
| Kibirkstis Trader Ltd | Administrative & support | 2019 |
| Kibo Group Ltd | Professional & scientific | 2023 |
| Kicker Finance Group Limited | Financial services | 2017 |
| KID Silk Ltd | Wholesale & retail | 2023 |
| Kidasa Vision Productions Ltd | Information & communication | 2023 |
| Kiddywink Limited | Transport & logistics | 1988 |
| Kidishop Ltd | Wholesale & retail | 2013 |
| Kidlet Creation Limited | Wholesale & retail | 2019 |
| Kidney Wales Charity | Health & social care | 1988 |
| Kids and Coffee Ltd | Arts & recreation | 2026 |
| Kids Empire Ltd | Wholesale & retail | 2022 |
| Kids Information Centre Ltd | Professional & scientific | 2019 |
| Kids Mayhem (Margate) Ltd | Health & social care | 2020 |
| Kidscolourtime Ltd | Wholesale & retail | 2025 |
| Kidson Properties Limited | Real estate | 1988 |
| Kidura Ltd | Wholesale & retail | 2025 |
| Kieranjr Ltd | Wholesale & retail | 2023 |
| Kiero Labs Ltd | Information & communication | 2026 |
| Kifaru Gold Ltd | Professional & scientific | 2020 |
| Kigg Ltd | Manufacturing | 2005 |
| Kigg Solutions Ltd | Real estate | 2024 |
| KIH Store Ltd | Wholesale & retail | 2024 |
| Kiimolo Ltd | Wholesale & retail | 2022 |
| Kiing K MNY LDN Ltd | Manufacturing | 2020 |
| Kijuvuk Ltd | Wholesale & retail | 2024 |
| Kik's Ltd | Other services | 2025 |
| Kiki Direct Ltd | Wholesale & retail | 2019 |
| Kikin Financial Limited | Financial services | 2023 |
| Kikipo Services Ltd | Wholesale & retail | 2021 |
| Killer Candy Ltd | Wholesale & retail | 2024 |
| Killgan Ltd | Administrative & support | 2020 |
| Killia Ltd | Hospitality | 2025 |
| KIM & Terry Limited | Professional & scientific | 2023 |
| KIM and Juliet Limited | Transport & logistics | 2019 |
| KIM Chapman Camerawork Ltd | Information & communication | 2018 |
| KIM Choo Ltd | Hospitality | 2013 |
| Kim's Consultancy Limited | | 2008 |
| Kimadrop Ltd | Wholesale & retail | 2025 |
| Kimani Consulting Ltd | Professional & scientific | 2016 |
| Kimbicael Ltd | Wholesale & retail | 2025 |
| Kimgab Ltd | Health & social care | 2019 |
| Kimi Properties Ltd | Real estate | 2023 |
| Kimibeauty Ltd | Wholesale & retail | 2018 |
| Kimmese Ltd | Wholesale & retail | 2025 |
| KIMOR08 Limited | Construction | 2019 |
| Kims Nails Salon Ltd | Other services | 2025 |
| KIN + ILK Brunel House Limited | Hospitality | 2017 |
| KIN + ILK Capital Quarter Limited | Hospitality | 2015 |
| KIN + ILK Capital Tower Limited | Hospitality | 2015 |
| KIN + ILK Limited | Hospitality | 2018 |
| KIN + ILK Pontcanna Limited | Hospitality | 2015 |
| KIN + ILK ST Davids Limited | Hospitality | 2018 |
| KIN + ILK the Maltings Ltd | Hospitality | 2018 |
| KIN Environmental Ltd | Professional & scientific | 2022 |
| KIN MEI Ltd | Real estate | 2023 |
| KIN2CARE Ltd | Hospitality | 2026 |
| Kinama Limited | Health & social care | 2012 |
| Kinbee Ltd | Administrative & support | 2017 |
| Kind Bear Limited | Arts & recreation | 2019 |
| Kind-Evolution Ltd | Education | 2019 |
| Kindamerch Ltd | Wholesale & retail | 2025 |
| Kindersley Research Limited | Public administration | 2016 |
| Kindwood Ltd | Agriculture & fishing | 2019 |
| Kinellma Group Limited | Financial services | 2025 |
| Kinetic Associates Ltd | Wholesale & retail | 2019 |
| Kinetic Gels Ltd | Extraterritorial | 2019 |
| Kinetic Mechanical Services Group Limited | Manufacturing | 2025 |
| Kinetic Resolve AI Ltd | Information & communication | 2023 |
| Kineticarenet UK Limited | Health & social care | 2016 |
| Kineticore Tech Limited | Information & communication | 2019 |
| Kinfah Ltd | Wholesale & retail | 2024 |
| King of Biryani Ltd | Hospitality | 2026 |
| King Security Limited | Administrative & support | 2026 |
| King Solomon's Paving Ltd | Construction | 2024 |
| King's Cashmere Co. Ltd. | Manufacturing | 2021 |
| King, Taudevin & Gregson Limited | Manufacturing | 1918 |
| Kingdom Capital Management Limited | Financial services | 2017 |
| Kingdom Executive Travel Ltd | Transport & logistics | 2025 |
| Kingdom of Sheba Yemen Ltd | Hospitality | 2025 |
| Kingdom Property Solutions Ltd | Households | 2019 |
| Kingdom Property Sourcing Ltd | Real estate | 2019 |
| Kingdomestic Cleaning Ltd | Administrative & support | 2020 |
| Kingel Business PC | | 2014 |
| Kingfisher (the Film) Ltd | Information & communication | 2018 |
| Kingfisher Investment Group Limited | Administrative & support | 2009 |
| Kingfisher Keys Ltd | Real estate | 2021 |
| Kingiliki Limited | Wholesale & retail | 2017 |
| Kingman Audio Limited | Information & communication | 2013 |
| Kings Mews (Cardiff) Management Company Limited | Households | 2005 |
| Kings Monkton School Limited | Education | 2018 |
| Kings Roofing and Property Maintenance Limited | Construction | 2017 |
| Kings Roofing Ltd | Construction | 2024 |
| Kings Security U.K. Ltd | Financial services | 2018 |
| KINGS11 Ltd | Real estate | 2018 |
| Kingsbridge Medical Limited | Health & social care | 2018 |
| Kingsbury Court (Boreham) Management Company Limited | Households | 1988 |