| Jkvisuals Ltd | Professional & scientific | 2010 |
| JLD Management Limited | Other services | 2015 |
| JM William Limited | Professional & scientific | 2016 |
| JMC (Stratford) Limited | Wholesale & retail | 2005 |
| JME Property Developments Ltd | Real estate | 2023 |
| JMS Corporate Consultancy Limited | Professional & scientific | 2023 |
| Jodha Legal Ltd | Professional & scientific | 2019 |
| Joel Stanley Enterprises Ltd | Administrative & support | 2013 |
| John Allen LLP | | 2008 |
| John Hughes Consultancy Services Limited | Professional & scientific | 2016 |
| Johnson Developments Limited | Administrative & support | 2009 |
| Jojoba Limited | Financial services | 2001 |
| Jolt Property Holdings Ltd | Real estate | 2025 |
| Jolt Stream Holdings Limited | Financial services | 2024 |
| Jonathanbrain.Com Limited | Professional & scientific | 2010 |
| Jora Limited | Information & communication | 2020 |
| Joseph Mills Architects Ltd | Construction | 2023 |
| Journey Accessories Ltd | Wholesale & retail | 2025 |
| Journey Campervan Conversions Ltd | Manufacturing | 2019 |
| Joyful Stone Ltd | Wholesale & retail | 2020 |
| JP Planning Ltd | Professional & scientific | 2007 |
| Jptl Engineering Limited | Administrative & support | 2009 |
| JRM Design Ltd | Construction | 2026 |
| JRO Limited | Financial services | 1998 |
| JS & RK Property Investments Limited | Real estate | 2023 |
| JS Refresh Cleaning Services Ltd | Administrative & support | 2025 |
| JS Watch Shop Ltd | Wholesale & retail | 2013 |
| Jsac Services Limited | Health & social care | 2022 |
| JSK Significance Ltd | Health & social care | 2019 |
| JSW7 Property Limited | Real estate | 2020 |
| Julian Dodsworth Limited | Wholesale & retail | 2010 |
| Julyan Property Ltd | Construction | 2017 |
| Juno Wealth Ltd | Real estate | 2018 |
| Jupiter Productions Limited | Construction | 2012 |
| Jurancon Ltd | Manufacturing | 2019 |
| Just Care Holdings Ltd | Real estate | 2025 |
| Just Care Solutions Ltd | Health & social care | 2023 |
| Just Grilles Ltd | Wholesale & retail | 2017 |
| Justaroo Limited | Education | 2018 |
| Justify Limited | Administrative & support | 2024 |
| Justmaths Consulting Limited | Education | 2014 |
| Justrrate Limited | Information & communication | 2026 |
| JWC Group Holdings Ltd | Professional & scientific | 2025 |
| JYH Ltd | Agriculture & fishing | 2020 |
| K & SW Construction Ltd | Construction | 2014 |
| K H Accountants Limited | Professional & scientific | 2007 |
| K M M Site Management Ltd | Construction | 2015 |
| K R Contracts Limited | Construction | 2009 |
| K&N Hospitality Ltd | Hospitality | 2026 |
| K'S Katerers Ltd | Hospitality | 2021 |
| K.A.W. Kitchen and Bedroom Installations Limited | Construction | 2022 |
| K.I.N.D Technologies Ltd | Information & communication | 2026 |
| Kaelo Limited | Professional & scientific | 2016 |
| Kaelo London Limited | Administrative & support | 2018 |
| Kaelo Manufacturing Limited | Manufacturing | 2016 |
| Kaelo Stand-Alone Limited | Administrative & support | 2024 |
| Kaelo Technology Limited | Administrative & support | 2016 |
| Kaezen Limited | Manufacturing | 2010 |
| Kaizen Official Ltd | Wholesale & retail | 2024 |
| KAM I.T Holdings Ltd | Professional & scientific | 2015 |
| Karin Vape Ltd | Wholesale & retail | 2025 |
| Karm Health & Beauty Ltd | Manufacturing | 2024 |
| KAT CHU Ltd | Other services | 2024 |
| Kate Bennett Limited | Professional & scientific | 2018 |
| Katie Barnes Training Academy Ltd | Wholesale & retail | 2017 |
| Katieh Locum Ltd | Administrative & support | 2016 |
| Kawaii Design Limited | Professional & scientific | 2025 |
| Kayeprop Ltd | Real estate | 2017 |
| KC Environmental Services Ltd | Water & waste | 2024 |
| Keane Consult LLP | | 2009 |
| Kenilworth Investments Holdings Limited | Financial services | 2016 |
| Kenilworth Investments Limited | Real estate | 1973 |
| Kennedy & Kennedy Properties Limited | Real estate | 2023 |
| Kennedys Stratford Limited | Real estate | 2016 |
| Keogh & Hows Limited | Professional & scientific | 2009 |
| KER Consultants Limited | Professional & scientific | 2025 |
| KES (Shakespeare's School) International Limited | Education | 2017 |
| Keshavala Property Limited | Real estate | 2022 |
| Kestrel Ridge LLP | | 2011 |
| Kevin Mckeown Consulting Limited | Professional & scientific | 2024 |
| Kevin Sumner Limited | Financial services | 2010 |
| Kevin Taylor Consultancy Services Ltd | Professional & scientific | 2019 |
| Keystone Collaborative Limited | Professional & scientific | 2025 |
| KF Contractors Limited | Construction | 2023 |
| KGL Consulting Limited | Professional & scientific | 2006 |
| KGT Consultancy Limited | Information & communication | 2008 |
| Kieran Jones Songs Limited | Arts & recreation | 2011 |
| Kiin Ltd | Wholesale & retail | 2010 |
| Kilpatrick IP Ltd | Professional & scientific | 2024 |
| KIM Pearson Ltd | Health & social care | 2018 |
| Kingdom Estates Limited | Construction | 2002 |
| Kingsley Court (Wellesbourne) Management Company Limited | Households | 2001 |
| Kingsman Estate Agents Limited | Real estate | 2017 |
| Kingwalker Ltd | Manufacturing | 2025 |
| Kink Resistant Hose Company Ltd | Wholesale & retail | 2023 |
| Kirisun UK Limited | Other services | 2017 |
| Kitchens by Dexter Limited | Manufacturing | 2014 |
| Kiwatech Limited | Professional & scientific | 2020 |
| Kiwi Construction Ltd | Construction | 2021 |
| KJC Books Ltd | Extraterritorial | 2022 |