| Hydra Fire Limited | Administrative & support | 1993 |
| Hyre Group Limited | Administrative & support | 2023 |
| I for Design Ltd. | Wholesale & retail | 2008 |
| IAT Architecture Ltd | Information & communication | 2019 |
| Igrok Limited | Information & communication | 2011 |
| IL Noor Ltd | Hospitality | 2018 |
| Imagine & Create Ltd | Other services | 2018 |
| Independence Pathways Ltd | Health & social care | 2018 |
| Inexsys Limited | Wholesale & retail | 2014 |
| Infinity Test Limited | Information & communication | 2018 |
| Informed Associates Limited | Hospitality | 2016 |
| Ingenium Solutions Ltd | Professional & scientific | 1980 |
| Innerdownie Limited | Health & social care | 2019 |
| Innovate Prints Limited | Manufacturing | 2025 |
| Interactive Education Solutions Limited | Information & communication | 2006 |
| INTERROG8 Ltd | Information & communication | 2017 |
| Invicta Body Repairs Limited | Wholesale & retail | 2015 |
| Itopia Limited | Information & communication | 2014 |
| Itxcode Ltd | Information & communication | 2017 |
| J Alfred Services Ltd | Information & communication | 2022 |
| J M Coffey Flooring Limited | Construction | 2012 |
| J Simpson Waste Management Ltd | Water & waste | 2014 |
| J Wright & Co Ltd | Professional & scientific | 2008 |
| J2K Appliances Limited | Manufacturing | 2013 |
| Jackson and Sons Building Company Limited | Construction | 2019 |
| Jan's Metal Works Ltd | Manufacturing | 2017 |
| Jandu Consulting Limited | Professional & scientific | 2014 |
| Jcsom Ltd | Professional & scientific | 2022 |
| JDP Actuarial Solutions Limited | Professional & scientific | 2011 |
| JKL Interiors Ltd | Other services | 2006 |
| JLB Ltd | Financial services | 2019 |
| Joinery Fixing and Finishing Limited | Manufacturing | 2012 |
| Jones Restaurants Limited | Hospitality | 2015 |
| JP Houghton Projects Limited | Financial services | 2016 |
| JT Ansell Ltd | Professional & scientific | 2020 |
| Just Cando Limited | Transport & logistics | 2017 |
| Just the Letter B Limited | Professional & scientific | 2009 |
| JVK Solutions Limited | Administrative & support | 2016 |
| Jw-Customer Consultancy Ltd | Professional & scientific | 2014 |
| Jwood Projects Limited | Professional & scientific | 2012 |
| Karueria Gathambara Ltd | Other services | 2018 |
| Karuna Fashions Limited | Wholesale & retail | 2019 |
| Kasaku Limited | Information & communication | 2015 |
| KAT Information Ltd | Information & communication | 2018 |
| Katsa Limited | Wholesale & retail | 2019 |
| Kenmac Ltd | Professional & scientific | 2018 |
| Kent Auto Care Ltd | Wholesale & retail | 2013 |
| Killian Construction Ltd | Construction | 2017 |
| Kintsugi Solutions Limited | Professional & scientific | 2021 |
| Klaspad Limited | Information & communication | 2016 |
| KLG Transport Ltd | Transport & logistics | 2019 |
| KLR Technology Ltd | Administrative & support | 2020 |
| Koysor Ltd | Information & communication | 2012 |
| KW IT Solutions Ltd | Information & communication | 2019 |
| Kyle Knowles Tiling Ltd | Construction | 2018 |
| L & S Burton Limited | Professional & scientific | 2014 |
| L Hannigan Limited | Administrative & support | 2010 |
| Lamb of Rhos Ltd | Hospitality | 2024 |
| Landscape Solutions Group Ltd | Administrative & support | 2021 |
| Larkspur & Lavender Limited | Wholesale & retail | 2017 |
| LBS Associates Ltd | Wholesale & retail | 2012 |
| Ldob Ltd | Hospitality | 2019 |
| Ledver Limited | Administrative & support | 2021 |
| Leeds and District Roofing Ltd | Construction | 2020 |
| Lewis Fire Protection Ltd | Public administration | 2014 |
| Lewis Keyes Developments Ltd | Construction | 2018 |
| LF Design Ltd | Administrative & support | 2016 |
| Ligget Sea Limited | Information & communication | 2007 |
| Lillis Consulting Limited | Financial services | 2020 |
| Little People Store Ltd | Wholesale & retail | 2018 |
| Liverpool Vape Shack Ltd | Wholesale & retail | 2015 |
| Logic Leap Solutions Limited | Information & communication | 2023 |
| Loma Technologies Ltd | Wholesale & retail | 2021 |
| London Cake Store Ltd | Manufacturing | 2020 |
| London Installations Services Ltd | Construction | 2020 |
| London Needs Scaffold Limited | Construction | 2015 |
| Long Eaton Scaffolding Limited | Construction | 2007 |
| Luculenta Limited | Information & communication | 2008 |
| Lusso Life Ltd | Wholesale & retail | 2018 |
| LV Sealants Ltd | Construction | 2018 |
| M Hilless Stone Supplies Limited | Manufacturing | 2001 |
| M T Akram Limited | Administrative & support | 2010 |
| M.R. Ives. Mechanical Ltd | Construction | 2013 |
| M.S.T. Property Limited | Real estate | 2001 |
| Maas QA Services Limited | Professional & scientific | 2019 |
| Mabware Limited | Information & communication | 2018 |
| Mack Engineering Ltd | Information & communication | 2003 |
| Mackey Consulting Limited | Information & communication | 2014 |
| MAD Financial Contractors Ltd | Financial services | 2015 |
| Made Construction Consultants Limited | Construction | 2019 |
| Maek Creative Limited | Professional & scientific | 2018 |
| Mala Aesthetics Ltd | Other services | 2021 |
| Mamma's and More Limited | Hospitality | 2020 |
| Mandez Trading Limited | Wholesale & retail | 2010 |
| Manuel Cueto Solutions Ltd | Information & communication | 2024 |
| Marchand Limited | Wholesale & retail | 2003 |
| Marletta Ltd | Hospitality | 2023 |
| Martin LEE Limited | Professional & scientific | 2015 |
| Master Brickwork London Essex Limited | Construction | 2014 |
| Matrix Mechanical Limited | Construction | 2015 |