| Curtain Ring Productions Ltd | Information & communication | 2014 |
| Custom Brand Co Ltd | Administrative & support | 2023 |
| Custom Shirts Ltd | Wholesale & retail | 2012 |
| Customhouse Studio Ltd | Professional & scientific | 2020 |
| CV Rail and Construction Ltd | Construction | 2023 |
| CWM Dulas Construction Ltd | Administrative & support | 2022 |
| CXP Carpentry & Building Ltd | Construction | 2024 |
| Cyber Network Defence Ltd | Information & communication | 2010 |
| Cyberguard Solutions SW Limited | Information & communication | 2025 |
| Cyberian Developments Limited | Professional & scientific | 2023 |
| Cybersentinel Innovations Limited | Information & communication | 2023 |
| Cycles Learning Centre Ltd | Education | 2019 |
| Cycology Bikes Limited | Wholesale & retail | 2012 |
| Cygnia Logistics Limited | Transport & logistics | 1999 |
| Cyril H. Thomas Limited | Wholesale & retail | 2011 |
| Cytation Consultancy Ltd | Information & communication | 2013 |
| D & a Removals Ltd | Transport & logistics | 2025 |
| D & a Training & Assessment Ltd | Other services | 2015 |
| D & H Burry Ltd | Construction | 2025 |
| D & H Surveys Limited | Professional & scientific | 2018 |
| D Banks Contractors Ltd | Agriculture & fishing | 2026 |
| D E & J L Ayers Limited | Health & social care | 2014 |
| D E Swannack Limited | Construction | 2014 |
| D J Security Limited | Administrative & support | 1998 |
| D Jones Building Development Limited | Construction | 2006 |
| D K Barnsley & Sons Ltd | Transport & logistics | 2014 |
| D L Halhead Limited | Construction | 2003 |
| D R Jones Engineering Ltd | Professional & scientific | 2025 |
| D&D Essentials Ltd | Wholesale & retail | 2024 |
| D&H Burry Properties Ltd | Real estate | 2026 |
| D&L Guley Hold Co Ltd | Financial services | 2023 |
| D&Y Consulting Limited | Administrative & support | 2019 |
| D'Arcy Lawes Limited | Construction | 2003 |
| D.M.S. Engineering Limited | Other services | 1997 |
| D.P. Smith Builders & Building Supplies Limited | Construction | 1998 |
| D.R. Flying Club Limited | Other services | 1984 |
| D3 Unmanned Ltd | Professional & scientific | 2017 |
| DA & MDM Awre Limited | Agriculture & fishing | 2024 |
| Dadulthood Ltd | Information & communication | 2024 |
| Daisy Diamond Ltd | Information & communication | 2024 |
| Dale Sugg Master Thatchers Ltd | Construction | 2015 |
| Dalepak Holdings Limited | Financial services | 1998 |
| Dalepak Limited | Transport & logistics | 2017 |
| Dalton Media Ltd. | Professional & scientific | 2018 |
| Damage Undone Limited | Wholesale & retail | 2005 |
| Damon Murphy Properties Limited | Real estate | 2021 |
| Dana Strand Limited | Professional & scientific | 2006 |
| Daniel Corp Building and Landscape Gardening Ltd | Administrative & support | 2025 |
| Daniel Preece Ltd | Manufacturing | 2014 |
| Daniell and Hole Limited | Agriculture & fishing | 2017 |
| Danlers Limited | Manufacturing | 1990 |
| Daqs Group Ltd | Manufacturing | 2006 |
| Daqs Manufacturing Ltd | Manufacturing | 2016 |
| Daqs Technical Solutions Ltd | Manufacturing | 2025 |
| Daresay Media Limited | Professional & scientific | 2017 |
| Darnell's Estate Ltd | Administrative & support | 2020 |
| Darren J Hewer (Calne) Limited | Construction | 2005 |
| Darsnipri Management Consultancy Limited | Professional & scientific | 2020 |
| Darwen Limited | Financial services | 2016 |
| Datared Limited | Information & communication | 2003 |
| Dauntsey Group Limited | Financial services | 2024 |
| Dauntsey Phoenix Community Interest Company | Information & communication | 2008 |
| Dauntsey Preserves Limited | Manufacturing | 2021 |
| Dauntsey Stableyard Management Company Limited | Households | 1998 |
| Dauntsey Vale Link Scheme Community Interest Company | Other services | 2008 |
| Dauntseywindowsanddoors Limited | Construction | 2025 |
| Davandali Limited | Administrative & support | 2023 |
| Dave REA Construction Limited | Construction | 2025 |
| Dave Wolf Construction Limited | Construction | 2014 |
| David Brunskill Limited | Health & social care | 2003 |
| David Horton Contractors Limited | Construction | 1993 |
| David Ingram Residential Limited | Real estate | 2004 |
| David Kerr Engineering Consultant Ltd | Administrative & support | 2010 |
| David Milligan Property Consultancy Ltd | Professional & scientific | 2015 |
| David Rhys Enterprises Limited | Information & communication | 2000 |
| David Treanor Camera Operator Limited | Professional & scientific | 2006 |
| Davies & Robson Consultancy Services Limited | Professional & scientific | 2017 |
| Davies & Verhage Ltd | Professional & scientific | 2016 |
| Davis Assets Limited | Construction | 2023 |
| Davis Groundworks Limited | Construction | 2006 |
| Davis Real Estate Ltd | Real estate | 2024 |
| DB Bathrooms Limited | Wholesale & retail | 2017 |
| DB Facilities Solutions Limited | Professional & scientific | 2016 |
| DBP Systems Limited | Administrative & support | 2005 |
| DBS Web Services Limited | Administrative & support | 2010 |
| DC Education and Training Ltd | Education | 2016 |
| DC Excavations Limited | Administrative & support | 2010 |
| DCE Electrical Contractors Ltd | Construction | 2024 |
| Dcsassociates Ltd | Professional & scientific | 2006 |
| DE Fossard Communications Ltd | Professional & scientific | 2016 |
| DE Vries & Partners Limited | Financial services | 1990 |
| Deathproof Industries Ltd | Wholesale & retail | 2017 |
| Declan Williams Limited | Construction | 2007 |
| Declan Williams Property Ltd | Real estate | 2026 |
| Deep Blue Beyond Ltd | Information & communication | 2026 |
| Deep END Media Limited | Information & communication | 2006 |
| DEH Chiropractic Limited | Health & social care | 2010 |
| Delectus Events Limited | Administrative & support | 2016 |
| Delfi Partners Limited | Professional & scientific | 2018 |
| Delicious Again Peter Limited | Professional & scientific | 2021 |