| Innerveative Health Solutions Ltd | Health & social care | 2013 |
| Innovative Medicine Limited | Health & social care | 2016 |
| Innsitz Ltd | Real estate | 2021 |
| Insight Deportivo Ltd | Professional & scientific | 2025 |
| Insight Leadership Community Interest Company | Administrative & support | 2023 |
| Installs (UK) Limited | Construction | 2014 |
| Integrated Style Ltd | Wholesale & retail | 2014 |
| Interlingo Ltd | Information & communication | 2023 |
| Investment and Holdings Limited | Professional & scientific | 2025 |
| Invicta Rentals Limited | Real estate | 2011 |
| Iris & Violet (Stamford) Ltd | Wholesale & retail | 2019 |
| Ironclad Services Ltd | Professional & scientific | 2026 |
| Isentu Limited | Information & communication | 2019 |
| IVO Consulting Solutions Limited | Professional & scientific | 2017 |
| Ivor Crowson Developments (Stamford) Limited | Real estate | 1975 |
| Ivory Court Management Limited | Real estate | 1997 |
| J & G Wakefield Limited | Construction | 2020 |
| J & L Ball Interiors Limited | Wholesale & retail | 2009 |
| J P S Electrical Services Ltd. | Construction | 1999 |
| J V S Roofing Limited | Construction | 2022 |
| J&B Drivers Ltd | Transport & logistics | 2013 |
| J&J Mackintosh Limited | Real estate | 2019 |
| J. M. S. Fencing Limited | Construction | 2009 |
| Jackline Consulting Limited | Professional & scientific | 2020 |
| Jackson’S Homes Ltd | Real estate | 2021 |
| JAK Frisby Design Ltd | Professional & scientific | 2022 |
| JAL Sagor Ltd | Hospitality | 2016 |
| Jamb Joinery Limited | Manufacturing | 2024 |
| James Boughton Landscaping Ltd | Administrative & support | 2023 |
| James Bowman Consulting Limited | Professional & scientific | 2013 |
| James Cannings Consulting Limited | Professional & scientific | 2022 |
| James Murray Financial Services Ltd | Financial services | 2022 |
| James Spindlow Construction Limited | Construction | 2007 |
| James-Bird Ltd | Administrative & support | 2019 |
| Janfield Nurseries Limited | Agriculture & fishing | 2017 |
| Jaro-Trans Ltd | Transport & logistics | 2021 |
| Jason Griffiths Transport Services Ltd | Transport & logistics | 2016 |
| Jason Halsey Consulting Ltd | Professional & scientific | 2020 |
| Jasper Enterprises Limited | Professional & scientific | 2007 |
| JAW Capital Ltd | Real estate | 2017 |
| JAXX91 Ltd | Transport & logistics | 2026 |
| JAY Lansdowne Partnership Ltd | Real estate | 2017 |
| JC + Co Furniture Limited | Manufacturing | 2023 |
| JDI4 Limited | Information & communication | 2016 |
| JDK Fitness Ltd | Education | 2020 |
| Jennings Design Consultancy Limited | Professional & scientific | 2013 |
| Jentill & Co Ltd | Wholesale & retail | 2026 |
| Jessica Anne Clarke Limited | Health & social care | 2019 |
| JGD Automotive Ltd | Wholesale & retail | 2024 |
| JIG Fixing Limited | Construction | 2011 |
| Jinju CHA Ltd | Wholesale & retail | 2024 |
| JK Henderson Electrical and Mechanical Services Limited | Manufacturing | 2016 |
| Jltg Limited | Hospitality | 2024 |
| JM & NJ Hall Properties Ltd | Real estate | 2022 |
| JM Trading International Ltd | Manufacturing | 2026 |
| Jmanningmedia Ltd | Professional & scientific | 2014 |
| JMB Associates Ltd | Real estate | 2019 |
| JMS Carpentry and Joinery Limited | Manufacturing | 2012 |
| JO Milnes Limited | Professional & scientific | 2013 |
| JOE Girling Consulting Ltd | Professional & scientific | 2025 |
| JOE Properties Ltd | Real estate | 2018 |
| Johan Truter Limited | Other services | 2009 |
| John Goodliffe Associates Limited | Construction | 2007 |
| John Mcgeeney Engineering Consultants Limited | Professional & scientific | 2024 |
| John's Swim School Ltd | Arts & recreation | 2011 |
| JON Urry Limited | Information & communication | 2014 |
| Jonathan Harvey Upholstery Limited | Other services | 2012 |
| Jonathon Hartley Limited | Professional & scientific | 2012 |
| Jones and Brown Limited | Construction | 2005 |
| Jordan FOX Cars Ltd | Wholesale & retail | 2023 |
| Josephblends Limited | Other services | 2025 |
| Josh Shaw Property Ltd | Real estate | 2015 |
| JP Electrical & Maintenance Ltd | Construction | 2022 |
| JPC Contracting Services Ltd | Construction | 2022 |
| JPS Property Developments (UK) Limited | Professional & scientific | 2005 |
| JT Insights Consulting Ltd | Professional & scientific | 2025 |
| JTM Power Solutions Limited | Professional & scientific | 2017 |
| Jubilate Partners Limited | Professional & scientific | 2002 |
| Judies Food Solutions Ltd | Wholesale & retail | 2025 |
| Juji Academy Ltd | Other services | 2017 |
| Just Jones Ltd | Manufacturing | 2018 |
| Just Solutions Consultancy Ltd | Professional & scientific | 2024 |
| Jvh.Digital Ltd | Information & communication | 2026 |
| JW Staff Properties Ltd | Construction | 2025 |
| JY Logistics Ltd | Professional & scientific | 2021 |
| Kaamit Ltd | Health & social care | 2015 |
| KAJ Industries Ltd | Manufacturing | 2000 |
| Kalios Ltd | Health & social care | 2025 |
| Kammax Ltd | Transport & logistics | 2023 |
| Kamsei Group Ltd | Professional & scientific | 2024 |
| Karaouine Ltd | Hospitality | 2014 |
| Karen Wright Marketing Communications Limited | Professional & scientific | 2006 |
| Karl Chapman Associates Limited | Professional & scientific | 2018 |
| Kata Tipis Ltd | Manufacturing | 2014 |
| Kate Bateman Ltd | Arts & recreation | 2024 |
| Kate Jennings Coaching Limited | Professional & scientific | 2009 |
| Kaus Media Ltd | Information & communication | 2023 |
| Kaye Space Ltd | Extraterritorial | 2013 |
| Kbpm Consultancy Limited | Other services | 2026 |
| KCL & H Trustee Company Limited | Education | 2016 |