| Cybernauts Limited | Information & communication | 2021 |
| Cygnus Tech Solutions Ltd | Information & communication | 2019 |
| Cyplo Group Holdings Limited | Financial services | 2026 |
| D Bird Services Limited | Professional & scientific | 2023 |
| D E Hunter Limited | Professional & scientific | 2012 |
| D G Rogers Plastering Contractors Ltd. | Construction | 2018 |
| D Holmes Logistics Consultancy Ltd | Professional & scientific | 2018 |
| D M Cager (Financial Services) Limited | Financial services | 2008 |
| D P Securities Limited | Real estate | 1984 |
| D Sanja Consultancy Ltd | Information & communication | 2010 |
| D&S Fletcher Ltd | Wholesale & retail | 2021 |
| D-Link Technologies Limited | Information & communication | 2017 |
| D.E.S. Communications Limited | Professional & scientific | 2004 |
| Dabs Garden Maintenance Ltd | Administrative & support | 2020 |
| DAC Logistics Limited | Transport & logistics | 2014 |
| Dafix UK Limited | Construction | 2015 |
| Daily Deli Limited | Hospitality | 2023 |
| Daisyfm Limited | Administrative & support | 2015 |
| Daksha Vinayaka Limited | Administrative & support | 2026 |
| Dalex Hospitality Limited | Hospitality | 2010 |
| Damavand Carpentry Ltd | Manufacturing | 2026 |
| DAN and GEO Ltd | Information & communication | 2007 |
| DAN Housego Cricket Coaching Limited | Education | 2017 |
| Danbury Court (Wokingham) Residents Management Company Limited | Households | 2006 |
| Danby Consulting Ltd | Professional & scientific | 2018 |
| Dancewm Limited | Arts & recreation | 2024 |
| Dandamudi's Limited | Real estate | 2023 |
| Danesfield Management Company Limited | Real estate | 1998 |
| Dansac Limited | Manufacturing | 1977 |
| Danteo Digital Limited | Information & communication | 2025 |
| Danum Associates Limited | Professional & scientific | 2005 |
| DAO in Aeternum Ltd | Education | 2023 |
| Dapperscape Ltd | Information & communication | 2024 |
| Dark Manta Group Ltd | Wholesale & retail | 2024 |
| Darkstar Consultancy Limited | Information & communication | 1997 |
| Daru Services Ltd | Information & communication | 2018 |
| Data AI Solutions Ltd | Information & communication | 2025 |
| Data Arch Solutions Limited | Information & communication | 2024 |
| Data Direct Holdings Limited | Professional & scientific | 2007 |
| Data Direct Thames Valley Limited | Information & communication | 1999 |
| Datalogy Limited | Professional & scientific | 2022 |
| Dataquest Consultancy Ltd | Information & communication | 2015 |
| Datastrive Limited | Information & communication | 2025 |
| Datazag Ltd | Information & communication | 2021 |
| Datelio LLP | | 2025 |
| Datology Solutions Limited | Information & communication | 1998 |
| Datrader Ltd | Professional & scientific | 2025 |
| Datum Right Limited | Information & communication | 2019 |
| Daval Enterprises Limited | Extraterritorial | 1983 |
| Davar Estates Limited | Real estate | 2019 |
| Dave Fretton & Co Decorators Limited | Construction | 1999 |
| David Cliff (Mortimer) Ltd | Real estate | 2015 |
| David Cliff Property Services Limited | Real estate | 2012 |
| David Colborn IT Services Ltd | Information & communication | 2024 |
| David Fenton Business Solutions Limited | Professional & scientific | 2021 |
| David Pollard Services Ltd | Construction | 2022 |
| Davids Lane Limited | Professional & scientific | 2025 |
| Davidsfocus Limited | Information & communication | 2024 |
| Davidson Architecture & Planning Ltd | Professional & scientific | 2024 |
| Davies Advisory Ltd | Professional & scientific | 2024 |
| Davis Planning Ltd | Administrative & support | 2014 |
| Daws & Associates Limited | Professional & scientific | 1998 |
| Daylight Redirecting Film Limited | Professional & scientific | 1995 |
| DBS Leisure Ltd | Administrative & support | 2020 |
| DD Executive Ltd | Transport & logistics | 2022 |
| DD Realtors Ltd | Real estate | 2025 |
| DE Beauvoir (NO.2) Residents Association Limited | Households | 1990 |
| DE Beauvoir Residents Association Limited | Households | 1992 |
| DE Novo Velo Ltd | Wholesale & retail | 2024 |
| DE Palma Ltd | Agriculture & fishing | 2021 |
| Dean Patterson Homes Ltd | Construction | 2017 |
| Deansgate Homes Communal Ltd | Households | 2023 |
| Dear Wealth Ltd | Wholesale & retail | 2020 |
| Debbie Bliss Limited | Professional & scientific | 2012 |
| Debbie Rees Bridal Limited | Wholesale & retail | 2018 |
| Debello Retail Limited | Administrative & support | 2014 |
| Deborah Sussex HR Consultancy Ltd | Professional & scientific | 2017 |
| Decent Systems Ltd. | Information & communication | 2017 |
| Decision Change Insight Limited | Professional & scientific | 2015 |
| Decodomo Furniture & Design Ltd | Wholesale & retail | 2024 |
| DEEGANS2024 Ltd | Hospitality | 2024 |
| Deegee Property Ltd | Real estate | 2021 |
| Deep Blue Pictures Limited | Information & communication | 2014 |
| Deers-Leap Insight Limited | Information & communication | 2018 |
| Defence Media Limited | Professional & scientific | 2019 |
| Defence Point Zero Limited | Information & communication | 2025 |
| Delete Alcohol Limited | Administrative & support | 2018 |
| Delicious Eats PVT Ltd | Hospitality | 2024 |
| Delita Limited | Manufacturing | 2020 |
| Delivering Happiness Limited | Wholesale & retail | 2016 |
| Deliversomething Ltd | Information & communication | 2026 |
| Delta Test Ltd | Professional & scientific | 2007 |
| Demaai Limited | Information & communication | 2026 |
| Demand Dogs Limited | Professional & scientific | 2018 |
| Denby Close (Wokingham) Management Company Limited | Households | 2009 |
| Dent-Pro Limited | Wholesale & retail | 2004 |
| Dentsmart Limited | Wholesale & retail | 2006 |
| Derek Finnie Associates Ltd | Professional & scientific | 2012 |
| Dermatology Processes Limited | Health & social care | 2022 |
| Design and Technical Management Limited | Professional & scientific | 2010 |