| Doc-Props Limited | Real estate | 2017 |
| DP Drums Limited | Administrative & support | 2022 |
| Dramatica Limited | Education | 2004 |
| Dreams and Beyond Ltd | Professional & scientific | 2012 |
| Drummond Court (Harrow) Residents Association Company Limited | Households | 1977 |
| Dunstable Developments Limited | Construction | 2020 |
| E & a Refurbs Ltd | Construction | 2023 |
| Eco Shine Cleaning Services Limited | Administrative & support | 2012 |
| Eco Shine Estate Ltd | Real estate | 2022 |
| Ecommerce Associates Property Investments Limited | Real estate | 1991 |
| Edge International Consultancy Ltd | Professional & scientific | 2023 |
| Edward Court Management (Harrow) Limited | Households | 1972 |
| Ekron Ltd | Professional & scientific | 2023 |
| Enigma Property Finance Ltd | Financial services | 2012 |
| Enjoi OIL Sales Limited | Wholesale & retail | 2025 |
| Equilibrium State Limited | Real estate | 2018 |
| Esra Sanro Limited | Professional & scientific | 2011 |
| ETT ALL Ltd | Administrative & support | 2011 |
| Eurowards Limited | Wholesale & retail | 1962 |
| Eventful Solutions Limited | Administrative & support | 2010 |
| Extendedrelative.Com Limited | Administrative & support | 2013 |
| Fantasticradiouk Limited | Professional & scientific | 2020 |
| Fashion Freedom Limited | Wholesale & retail | 2003 |
| Fearless Business Limited | Professional & scientific | 2018 |
| Ferax Estates Ltd | Administrative & support | 2015 |
| Fortesium Limited | Information & communication | 2010 |
| Fortiron Steel UK Limited | Wholesale & retail | 2024 |
| Forward Thinking Lettings Ltd | Households | 2013 |
| Fresque Limited | Professional & scientific | 2019 |
| Fritsch-Paul Properties Limited | Extraterritorial | 2003 |
| Frizma Limited | Real estate | 2016 |
| Funding NAV Capital Limited | Administrative & support | 2025 |
| Funding NAV Limited | Administrative & support | 2016 |
| Fusiondreams Ltd | Real estate | 2022 |
| G.V.B Ltd | Financial services | 2015 |
| Game Face Entertainment Limited | Manufacturing | 2022 |
| Gannon Associates Limited | Professional & scientific | 2002 |
| Gardonyi's Limited | Wholesale & retail | 2003 |
| Garibaldi Growth Limited | Wholesale & retail | 2025 |
| Gateway Recycling Limited | Wholesale & retail | 2016 |
| GGP (London) Ltd | Real estate | 2021 |
| Glasfryn Management Company Limited | Households | 1988 |
| Global Metcorp Limited | Wholesale & retail | 2001 |
| Global Sourcing & Trade Ltd | Real estate | 2010 |
| Golden Spiral AI Limited | Information & communication | 2024 |
| Grubworkz HQ Manufacturing Limited | Manufacturing | 2014 |
| Hair Loss London Ltd | Health & social care | 2024 |
| Hale Works Limited | Information & communication | 2013 |
| Happy Toasties Ltd | Hospitality | 2025 |
| Harrow Fields Gardens Estate Company Limited | Real estate | 1981 |
| Harrow Urology Limited | Health & social care | 2010 |
| Harshu Ltd | Professional & scientific | 2021 |
| Help With Your Home Move Limited | Transport & logistics | 2017 |
| Heymann Hansa Hamburg Limited | Real estate | 1984 |
| Highlawn Hall Freehold Limited | Households | 2001 |
| Honey Badger Estates Ltd | Real estate | 2021 |
| Hot Boss Brands Limited | Manufacturing | 2022 |
| Hotelogical Group Limited | Professional & scientific | 2014 |
| Howto Products Limited | Extraterritorial | 2011 |
| HTC Developments Limited | Real estate | 2019 |
| Hugh Strange Architects Limited | Professional & scientific | 2014 |
| Hungry Shredder Ltd | Water & waste | 2015 |
| Hurst Barn Conversions Limited | Construction | 2023 |
| Hutton and Cain Courts Management Limited | Households | 1974 |
| Impala Fabrics Limited | Wholesale & retail | 2008 |
| Implement (UK) NFP Limited | Professional & scientific | 2022 |
| Infinit Solutions Limited | Real estate | 1994 |
| Innovative Spirits Limited | Wholesale & retail | 2021 |
| Insight Business Development Limited | Professional & scientific | 1995 |
| Insparo Asset Management Limited | Financial services | 2007 |
| Intatec Consulting Limited | Extraterritorial | 2020 |
| Intra House (London) Developments Ltd | Construction | 2022 |
| IST Developments Limited | Real estate | 2016 |
| ITS City Limited | Administrative & support | 2009 |
| J&B Real Estate Ltd | Real estate | 2018 |
| Jadog Ltd | Administrative & support | 2014 |
| Jakes Holds Ltd | Manufacturing | 2022 |
| James Fuller Joinery Limited | Manufacturing | 2021 |
| Jayne Homes Limited | Real estate | 2015 |
| Jazzconnects Limited | Wholesale & retail | 2025 |
| Jazzy Bean Limited | Manufacturing | 2011 |
| Jermyn Street Advisory Ltd | Professional & scientific | 2022 |
| Jetstar Investments Limited | Real estate | 2013 |
| Joshua Simons & Associates Limited | Administrative & support | 2012 |
| Joshua Tree Productions Limited | Administrative & support | 2011 |
| Journeyforce Ltd | Information & communication | 2022 |
| Julian Court Property Management Limited | Households | 1976 |
| K Wright Consulting Limited | Professional & scientific | 2024 |
| Kaviman Company Limited | Construction | 2016 |
| Kencroft Limited | Wholesale & retail | 2005 |
| Kijul One Ltd | Real estate | 2023 |
| Kings Head Flat Management Limited | Households | 2004 |
| Kings Head Rent Charge Management Limited | Households | 2004 |
| Kingsland Place Limited | Education | 2025 |
| Kiris Group Ltd. | Administrative & support | 2017 |
| Kitch 'N' Sync Media Ltd | Information & communication | 2010 |
| Klaxon Limited | Professional & scientific | 2010 |
| Knowledge Avenue Limited | Administrative & support | 2013 |
| Konnected Plus Limited | Administrative & support | 2023 |
| Ktdt Ltd | Real estate | 2022 |