| JPR Plumbing & GAS Services Limited | Construction | 2022 |
| Jpservicesgroup.Uk Ltd | Administrative & support | 2017 |
| JR Plumbing, Heating and GAS Ltd | Construction | 2021 |
| JR Tyre Services Ltd | Wholesale & retail | 2025 |
| JRC Construction Services Ltd | Construction | 2024 |
| JRD Plastering Services Limited | Construction | 2025 |
| JRH Motorsport Ltd | Professional & scientific | 2024 |
| JRM Performance Ltd | Wholesale & retail | 2020 |
| Jrrm Medical Services Limited | Health & social care | 2025 |
| JS Ductwork Ltd | Construction | 2023 |
| JSK Clinical Services Limited | Professional & scientific | 2016 |
| JSO Carpentry & Building Limited | Construction | 2022 |
| JT Carpentry Construction Ltd | Manufacturing | 2020 |
| JT Duffett Limited | Construction | 2019 |
| JT Management Limited | Administrative & support | 2016 |
| JTD Property Investments Ltd | Real estate | 2025 |
| JTP Financial Limited | Financial services | 2022 |
| JTS Care Solutions Ltd | Health & social care | 2020 |
| Jubair Limited | Information & communication | 2020 |
| Judo Economics Limited | Professional & scientific | 2009 |
| Julie Toll Limited | Administrative & support | 2001 |
| Jumbotrans Ltd | Transport & logistics | 2016 |
| Jummie's Bukka Limited | Hospitality | 2023 |
| Jump CUT Pictures Ltd | Information & communication | 2025 |
| Junction 7 Creatives C.I.C. | Education | 2020 |
| Just BE a Child | Education | 2013 |
| Just Divine Healthcare Limited | Health & social care | 2011 |
| Just Finishing Ltd | Construction | 2025 |
| Just Fred Ltd | Information & communication | 2019 |
| Just Holding Something Ltd | Financial services | 2026 |
| Just Landscaping Design & Build Ltd | Administrative & support | 2025 |
| JWB ARB Ltd | Construction | 2017 |
| JWS Solutions Limited | Professional & scientific | 2001 |
| Jyotir Psychology and Wellbeing Ltd | Health & social care | 2023 |
| JZ Transport Taxi Limited | Transport & logistics | 2026 |
| JZO Solutions Limited | Professional & scientific | 2020 |
| K & K Autos Ltd | Wholesale & retail | 2007 |
| K Arch Limited | Real estate | 2017 |
| K Factor Records Ltd | Information & communication | 2013 |
| K GEE Global Ltd | Transport & logistics | 2020 |
| K Godleman Properties Ltd | Real estate | 2020 |
| K Nest Retail Ltd | Wholesale & retail | 2021 |
| K Ring Events Ltd | Information & communication | 2019 |
| K Skinner Film & TV Rigging Limited | Construction | 2010 |
| K Square Technology Limited | Information & communication | 2021 |
| K&B Craft Ltd | Construction | 2026 |
| K'S Nails Limited | Other services | 2015 |
| K-Entrain Phototherapy Ltd | Administrative & support | 2024 |
| K-Tec Microscope Services Ltd | Professional & scientific | 2012 |
| K.Bala Ltd | Hospitality | 2019 |
| K.C.J.M. Development & Construction Company Limited | Real estate | 2002 |
| K.D.J. Plumbing & Heating Limited | Construction | 2017 |
| K.D.T.C. Limited | Financial services | 2023 |
| K2J Khaira Ltd. | Information & communication | 2000 |
| K9 Lead Limited | Education | 2024 |
| K9 Records Limited | Other services | 2016 |
| Kaash Group Ltd | Wholesale & retail | 2022 |
| Kaash Properties Ltd | Real estate | 2024 |
| Kaashi Technologies Limited | Information & communication | 2024 |
| Kage Enterprise Ltd | Real estate | 2019 |
| Kaios Streetwear Ltd | Wholesale & retail | 2024 |
| Kalimat Limited | Wholesale & retail | 2024 |
| Kall Kurian Limited | Real estate | 2021 |
| Kallis Projects Limited | Wholesale & retail | 2016 |
| Kalm Estate Agents Limited | Real estate | 2021 |
| Kalstan Engineering Limited | Manufacturing | 1980 |
| Kamak Healthcare Limited | Health & social care | 2014 |
| Kamene Klass Ltd | Education | 2023 |
| Kancor Property Limited | Real estate | 2025 |
| Kandola Retail Limited | Wholesale & retail | 2015 |
| Kanegrade Limited | Manufacturing | 1980 |
| Kanes Drains Ltd | Water & waste | 2024 |
| Kara Tools Limited | Wholesale & retail | 2013 |
| Karakurt Limited | Hospitality | 2017 |
| Karbnz Cachoeira Ltd | Agriculture & fishing | 2025 |
| Karbnz Global Limited | Water & waste | 2024 |
| Karbnz UK Ltd | Manufacturing | 2024 |
| KARBON126 Ltd | Professional & scientific | 2025 |
| Karim Engineering Limited | Construction | 2008 |
| Kartalbjk Ltd | Hospitality | 2023 |
| Karue Holdings Limited | Financial services | 2025 |
| Kashavi Limited | Information & communication | 2016 |
| Kashora Properties Limited | Real estate | 2021 |
| Kassadox Ltd | Administrative & support | 2016 |
| Kasz Ltd | Construction | 2025 |
| KAT Glossy Rides Ltd | Wholesale & retail | 2024 |
| Kate Smith Jamison Ltd | Health & social care | 2015 |
| Katharine Mahoney Limited | Information & communication | 2007 |
| Kattrina Ltd | Wholesale & retail | 2026 |
| Katychiosa Ltd | Health & social care | 2021 |
| Kausi Ltd | Health & social care | 2024 |
| Kayacamper Ltd | Administrative & support | 2021 |
| Kaye Godleman Limited | Information & communication | 2008 |
| Kaylaa Limited | Wholesale & retail | 2026 |
| KB Production Chupa Limited | Information & communication | 2016 |
| Kbingram Ltd | Professional & scientific | 2013 |
| KBM Civils Limited | Construction | 2018 |
| KC Shield Roofing Ltd | Construction | 2026 |
| KCB Digital Limited | Administrative & support | 2024 |
| Kchr Accountancy Limited | Professional & scientific | 2020 |