| Cyjax Limited | Information & communication | 2012 |
| Cylon Investments Ltd | Financial services | 2020 |
| Cylon Limited | Administrative & support | 2017 |
| D & a Automotive Limited | Wholesale & retail | 2024 |
| D & D Builds Ltd | Construction | 2026 |
| D & L Advisory Limited | Professional & scientific | 2020 |
| D & S New and SON LLP | | 2013 |
| D & Y Access Solutions Limited | Construction | 2024 |
| D a Arnold Limited | Construction | 2019 |
| D Beckett Services Ltd | Professional & scientific | 2009 |
| D J R Miles Bathroom, Plumbing & Heating Engineers Limited | Construction | 2003 |
| D P Investments Limited | Construction | 2000 |
| D P Smith Limited | Real estate | 2001 |
| D Tipton Limited | Administrative & support | 2003 |
| D&B Construction & Groundworks Ltd | Construction | 2021 |
| D&D Commercial Properties Ltd | Real estate | 2020 |
| D&L Maintenance Services Ltd | Manufacturing | 2008 |
| D&M Environmental Limited | Construction | 2019 |
| D&R Limited | Real estate | 2026 |
| D'Oilly Manor Asset Management Ltd | Real estate | 2022 |
| D-Day Celebrant Ltd | Administrative & support | 2026 |
| D. J. Leslie Limited | Construction | 2003 |
| D.J. Miles Electrical Services Limited | Construction | 2005 |
| D.M.H. Services Limited | Real estate | 1999 |
| D.R Plumbing Limited | Construction | 2023 |
| Dabbl Group Limited | Administrative & support | 2014 |
| Dabbl Invest Limited | Administrative & support | 2017 |
| Dadal Consulting Limited | Professional & scientific | 2018 |
| Daeda Ltd | Professional & scientific | 2022 |
| Dahlia Beach Limited | Agriculture & fishing | 2021 |
| Dailey Hill House Management Limited | Households | 2014 |
| Daisy at the Dairy Limited | Wholesale & retail | 2025 |
| Daisy Chain Developments Ltd | Construction | 2024 |
| Daizy Solutions UK Ltd | Information & communication | 2020 |
| Daizy Tech Ltd | Information & communication | 2018 |
| Dale & Dale Solicitors Limited | Professional & scientific | 2013 |
| Dalgarno Associates Ltd | Professional & scientific | 2024 |
| DAN Bull SEN Mentoring & Support Ltd | Education | 2024 |
| Daniel Phipps Personal Training Ltd | Other services | 2014 |
| Dantoni Services Limited | Education | 2005 |
| Darby Advisory Ltd | Construction | 2026 |
| Darke & Taylor (Holdings) Limited | Professional & scientific | 2008 |
| Darke & Taylor Building Services Ltd | Construction | 2019 |
| Darke & Taylor Limited | Construction | 1971 |
| Darke & Taylor Trustee Limited | Extraterritorial | 2025 |
| Dash Group Holdings Limited | Financial services | 2025 |
| DAT Chauffeurs UK Limited | Transport & logistics | 2019 |
| Data DAM Ltd | Information & communication | 2007 |
| Datmac Ltd | Information & communication | 2021 |
| David Bull & Sons Limited | Administrative & support | 2024 |
| David J. White Limited | Wholesale & retail | 1964 |
| David New Scaffolding Limited | Construction | 2007 |
| Davidmoorelettings Limited | Real estate | 2004 |
| Davids Building Services Limited | Professional & scientific | 2005 |
| Dawnera Consulting Ltd | Information & communication | 2025 |
| Day 1 Displays Ltd | Professional & scientific | 2020 |
| Day Night Agency Consultancy Limited | Professional & scientific | 2020 |
| Day Night Agency Limited | Other services | 2022 |
| DAY2DAYGROUP Ltd | Professional & scientific | 2026 |
| DB Plant & SON Limited | Construction | 2025 |
| DB Plant Limited | Water & waste | 2009 |
| DB2 Capital Ltd | Construction | 2021 |
| DBS Decorations Limited | Construction | 2010 |
| DC Biotech Limited | Professional & scientific | 2026 |
| Dchampion Roofing Ltd | Construction | 2018 |
| DD Driver Services Ltd | Administrative & support | 2026 |
| DDJ Scaffolding Company Limited | Construction | 2019 |
| DE Beauvoir Capital Limited | Real estate | 2022 |
| DE Cunsel Consulting Ltd | Professional & scientific | 2020 |
| Dead Lion Mead Limited | Wholesale & retail | 2026 |
| Deals on the Doorstep Ltd | Information & communication | 2022 |
| Dean Harris Plumbing and Heating Ltd | Construction | 2022 |
| Deanfield Accountancy and Tax Services Limited | Professional & scientific | 2016 |
| Dear Mary Ltd | Wholesale & retail | 2024 |
| Decknics Ltd | Other services | 2020 |
| Decovista Group Ltd | Manufacturing | 2025 |
| DEFCON27 Limited | Professional & scientific | 2022 |
| Defiant Ones UK Limited | Wholesale & retail | 2023 |
| Defyne Ltd | Information & communication | 2015 |
| Delicious Food Consultants Limited | Professional & scientific | 2015 |
| Deliver 1-2-1 Limited | Other services | 2022 |
| Dellman Limited | Administrative & support | 2016 |
| Delphic 360 Ltd | Administrative & support | 2026 |
| Delrose Consulting Limited | Professional & scientific | 2009 |
| Delta Echo Victor Ltd | Information & communication | 2023 |
| Deltaarc Consulting Limited | Information & communication | 2025 |
| Deltasword Limited | Real estate | 2010 |
| Deltec Plumbing and Heating Ltd | Energy | 2014 |
| Delticom Limited | Wholesale & retail | 2001 |
| Denshams Butchers Limited | Wholesale & retail | 2002 |
| Deposit Return Solutions UK Ltd | Administrative & support | 2020 |
| Derwent House Living Ltd | Wholesale & retail | 2019 |
| Desert Rain Consultancy Ltd | Health & social care | 2025 |
| Desert Rain Property Ltd | Real estate | 2025 |
| Design Apparel Holdings Limited | Wholesale & retail | 2024 |
| Design the Inside Ltd | Other services | 2024 |
| Desire Property Group Ltd | Real estate | 2019 |
| Detra Consulting Ltd | Information & communication | 2022 |
| DFB Plumbing Services Limited | Construction | 2015 |
| DFX Technology Limited | Manufacturing | 2003 |