| Integrated Electronic Systems Limited | Professional & scientific | 1990 |
| Ishaani Capital Ltd | Construction | 2022 |
| Ishveen Food & Wine Limited | Wholesale & retail | 2014 |
| Isza Ltd | Health & social care | 2024 |
| Itida UK Limited | Information & communication | 2014 |
| Iver Film Production Limited | Information & communication | 2024 |
| J&J Properties (Surrey) Limited | Real estate | 2022 |
| J2K Traders Limited | Wholesale & retail | 2015 |
| JAI Krish Properties Limited | Real estate | 2024 |
| Jain's IT Solutions Limited | Information & communication | 2018 |
| Janak (London) Limited | Wholesale & retail | 2014 |
| Janak Fashions (London) Limited | Wholesale & retail | 2012 |
| JAY KAY Properties Limited | Real estate | 2018 |
| JAZ Property Management Ltd | Real estate | 2011 |
| Jeys Barber Ltd | Other services | 2015 |
| JJR Upil Homes Ltd | Real estate | 2024 |
| JK Food & Drinks Limited | Wholesale & retail | 2015 |
| JK Trading Limited | Administrative & support | 2016 |
| Joanatnutrition Limited | Hospitality | 2011 |
| JSK Properties Limited | Real estate | 2016 |
| JSV Properties Limited | Real estate | 2015 |
| Just FAB Catering Ltd | Hospitality | 2022 |
| Just Food Centre Ltd | Hospitality | 2023 |
| K&A Stores Limited | Wholesale & retail | 2019 |
| K'Arot Limited | Manufacturing | 2025 |
| K5 Mobile UK Limited | Wholesale & retail | 2023 |
| Kaizzen Tech Limited | Information & communication | 2019 |
| Kakkar Group Limited | Real estate | 2025 |
| Kalmm Ltd | Health & social care | 2005 |
| Kamboj Accountancy LLP | | 2008 |
| Kamla Tech Limited | Information & communication | 2024 |
| Kamlesh Fabrics Limited | Wholesale & retail | 2017 |
| Kanhaiya Investments Limited | Real estate | 2022 |
| Kapoor's Estates Limited | Real estate | 2022 |
| Karak Chaii Hillingdon Ltd | Hospitality | 2025 |
| Kastoor & Sons Limited | Real estate | 2019 |
| Khaneja Trading Limited | Wholesale & retail | 2020 |
| Kinwarton Wines Limited | Wholesale & retail | 2022 |
| Knight Young Estates Limited | Real estate | 2017 |
| Konnectstaff Ltd | Administrative & support | 2020 |
| KQ Movies Ltd | Information & communication | 2018 |
| Krishna Biju Services Ltd | Health & social care | 2013 |
| L.M.J. Marine & Industrial Engineering Ltd | Construction | 2023 |
| Lamba Food & Wine Ltd | Wholesale & retail | 2007 |
| Lamba G Food & Wine Limited | Wholesale & retail | 2014 |
| Larchwood Wildlife and Conservation Centre Limited | Arts & recreation | 2023 |
| Lavender Learn Limited | Professional & scientific | 2022 |
| Lettings@ Limited | Real estate | 2017 |
| Lionix Kitchen and Bedrooms Ltd | Construction | 2024 |
| Litechnica Limited | Health & social care | 1977 |
| Lloshi Barber Limited | Other services | 2022 |
| Londis Supermarket Limited | Wholesale & retail | 2015 |
| Lunaone Ltd | Information & communication | 2020 |
| Luxuryconciergeuk Ltd | Wholesale & retail | 2022 |
| M & C Tyres Limited | Wholesale & retail | 2003 |
| M Doody Plant Hire Ltd | Construction | 2020 |
| M S Auto Tyres Ltd | Wholesale & retail | 2023 |
| M W Jupp Enterprises Limited | Wholesale & retail | 1979 |
| M&M London Properties Limited | Real estate | 2024 |
| Mace Enterprises 1 Limited | Wholesale & retail | 2015 |
| Mace Enterprises Limited | Wholesale & retail | 2014 |
| Mani Gabba Enterprises Limited | Wholesale & retail | 2014 |
| Mani-Hamon Desserts Limited | Hospitality | 2018 |
| Masaani Estates Limited | Real estate | 2025 |
| Matharu Construction Limited | Construction | 2010 |
| Maxi Optics Limited | Administrative & support | 2018 |
| Meadowbank Construction Limited | Real estate | 1984 |
| Mechanaholic Limited | Wholesale & retail | 2024 |
| Media Medical Consultants Limited | Information & communication | 2016 |
| Medman Consultancy Limited | Health & social care | 2010 |
| Mednavi Limited | Manufacturing | 2024 |
| Merc Autobarn Ltd | Wholesale & retail | 2015 |
| Micado Homes Limited | Health & social care | 2006 |
| Middlesex Premier Construction Ltd | Construction | 2010 |
| Migrate Abroad Ltd | Information & communication | 2012 |
| Milaa Boutique Limited | Wholesale & retail | 2020 |
| Mill Street Food & Wine Limited | Wholesale & retail | 2019 |
| Million Star Investment Ltd | Real estate | 2018 |
| Millwrights Sustainable Solutions Ltd | Construction | 2024 |
| Minar Properties LLP | | 2025 |
| Mint Spoon Ltd | Hospitality | 2025 |
| MK Sweets Cash & Carry Ltd | Wholesale & retail | 2022 |
| Modern Kitchen & Bedroom Ltd | Manufacturing | 2023 |
| Monice UK Limited | Wholesale & retail | 2019 |
| Mooseys Limited | Wholesale & retail | 2016 |
| MSM Impex Limited | Wholesale & retail | 2018 |
| Musarrat Jehan Ltd | Professional & scientific | 2024 |
| Mutt & Jeff Pictures Limited | Information & communication | 2007 |
| My Choice Investments Ltd | Real estate | 2018 |
| My Feltham Property Ltd | Real estate | 2023 |
| Mykeys London Ltd | Construction | 2019 |
| Mylife Investments Limited | Real estate | 2020 |
| N P Express Ltd | Transport & logistics | 2021 |
| N-Hanz Properties Ltd | Real estate | 2024 |
| Nabab Restaurant Ltd | Hospitality | 2011 |
| Nasiry & Sons Limited | Wholesale & retail | 2025 |
| Nasrat Limited | Hospitality | 2019 |
| Nationwide Properties Group Ltd | Real estate | 2022 |
| Nayyar Stores Limited | Wholesale & retail | 2016 |
| Neelam Prop UK Limited | Real estate | 2018 |