| Croye House Residents Society Limited | Households | 1970 |
| Cubicle Washroom Systems Limited | Manufacturing | 2015 |
| Custom Covers Holdings Limited | Manufacturing | 2002 |
| Custom Internet Limited | Information & communication | 1999 |
| CWG Construction and Landscaping Limited | Construction | 2003 |
| Cyclexperience Limited | Wholesale & retail | 2002 |
| D & D N.R.G Plumbing & Heating Limited | Construction | 2007 |
| D & G Decorating Solutions Ltd | Construction | 2005 |
| D & P Property Management (Portsmouth) Ltd | Extraterritorial | 2007 |
| D & S Ware Ltd | Real estate | 2006 |
| D D Brickworks Limited | Construction | 2005 |
| D J Salvage Limited | Wholesale & retail | 2003 |
| D N White Opticians Limited | Health & social care | 2003 |
| D.G.Oil TEC Ltd | Administrative & support | 2004 |
| Dabr Limited | Information & communication | 2002 |
| Dadeon Health Care Limited | Public administration | 2021 |
| Dahlers Jewellers Limited | Wholesale & retail | 2004 |
| Daily Developments Limited | Information & communication | 2000 |
| Daiwik Technical Solutions Limited | Information & communication | 2019 |
| DAL Sterling Consulting LLP | | 2002 |
| Dal-Sterling Group Ltd | Professional & scientific | 1983 |
| Damar (Emsworth) Limited | Other services | 2001 |
| Damerell Consulting Limited | Information & communication | 2007 |
| DAN Valeting Services Ltd | Wholesale & retail | 2024 |
| Daneswood Developments Limited | Real estate | 2022 |
| Daniel Lowe Ltd | Construction | 2007 |
| Daniels Close Management Company Limited | Hospitality | 2006 |
| Dantis Limited | Real estate | 2006 |
| Danville Limited | Professional & scientific | 1997 |
| Daren Brown Brickwork Limited | Construction | 2002 |
| Dart Consultants Limited | Professional & scientific | 1997 |
| Dartverge Property Management Limited | Households | 1984 |
| Data Centre Solutions Limited | Professional & scientific | 2003 |
| Datainfo Solutions Limited | Information & communication | 2002 |
| Datum Precision Tooling Limited | Water & waste | 1992 |
| Dave Noake Limited | Construction | 2004 |
| David Gamblin Limited | Professional & scientific | 2005 |
| David Shores & Co. Limited | Professional & scientific | 1980 |
| David Watson Ltd | Wholesale & retail | 2015 |
| Davies Consultancy Services Limited | Financial services | 2025 |
| Day View Group Ltd | Real estate | 2022 |
| Daysbright Ltd | Education | 2009 |
| Dazefield 2000 Limited | Construction | 1964 |
| DB Payroll Services Limited | Professional & scientific | 2002 |
| DCS Computing Skills Ltd | Information & communication | 2008 |
| DE Landro Consulting Limited | Information & communication | 2000 |
| Debbie Hingley Limited | Arts & recreation | 2007 |
| Debbie Jordan Limited | Professional & scientific | 2002 |
| DEC Associates Ltd | Professional & scientific | 2002 |
| DEC Building Maintenance Limited | Construction | 2007 |
| Decreeaero Limited | Professional & scientific | 1996 |
| Dectech Business Solutions Ltd. | Wholesale & retail | 1988 |
| Deep Blue C Technology Ltd | Information & communication | 2000 |
| Deep Blue Financial Limited | Financial services | 1999 |
| Deep Sea Seals Trustees Limited | Professional & scientific | 2002 |
| Delamere Services (UK) Limited | Information & communication | 2002 |
| Delamite Limited | Construction | 1994 |
| Delta Lima IT Consultancy Limited | Information & communication | 2008 |
| Demand Technology International Limited | Manufacturing | 1993 |
| Demand Technology Limited | Manufacturing | 1999 |
| Demolition Company Partnership Limited | Wholesale & retail | 1997 |
| Dennison Computer Solutions Limited | Information & communication | 2000 |
| Depthobtain Limited | | 1992 |
| Derek Douglas Walker Limited | Other services | 2012 |
| Design Electric Ltd | Construction | 2000 |
| Designbrook Limited | Professional & scientific | 1987 |
| Designcraft Limited | Professional & scientific | 1998 |
| Designs Alike Limited | Wholesale & retail | 1999 |
| Dever Springs (Angling) Limited | Arts & recreation | 1999 |
| Dever Stores Limited | Wholesale & retail | 2008 |
| Dewk Limited | Construction | 2019 |
| Dgtl Ltd | Information & communication | 2007 |
| Di-Line Limited | Construction | 2002 |
| Dial a Screen Limited | Wholesale & retail | 1998 |
| Diamond Quarter Property Ltd | Real estate | 2003 |
| Dibden Purlieu Carpets Limited | Wholesale & retail | 2005 |
| Dickinson Legg Group Limited | Professional & scientific | 2002 |
| Dida Property Ltd | Real estate | 2024 |
| Digital One Limited | Information & communication | 1998 |
| Digitalwise Limited | Wholesale & retail | 1999 |
| Dijital Technologies Limited | Information & communication | 2018 |
| Dimon Estate Agents Limited | Real estate | 2004 |
| Direct Accounts Limited | Professional & scientific | 1993 |
| Direct Resources Ltd | Hospitality | 2005 |
| Ditcham Park School Charity Association(The) | Education | 1982 |
| Divitec Limited | Wholesale & retail | 1999 |
| DJ IT Services Limited | Information & communication | 2007 |
| DK Management Co. Ltd. | Professional & scientific | 1986 |
| DO Shop Limited | Wholesale & retail | 2005 |
| Dolphin Homes Group Limited | Administrative & support | 2026 |
| Donag Limited | Professional & scientific | 1963 |
| Donald Malcolm Associates Limited | Administrative & support | 2005 |
| Donald W B Perrin Ltd. | Construction | 2006 |
| Dorset Congregational Association(Incorporated)(The) | Other services | 1919 |
| Dorys Garage (Sway) Limited | Wholesale & retail | 2007 |
| Doterus Limited | Wholesale & retail | 2026 |
| DPE Electrical Ltd | Construction | 2005 |
| DR A.L. Goldsmith Anaesthetics Ltd | Health & social care | 2002 |
| Draper Warehousing Company Limited | Real estate | 1979 |
| Drawtech Services Limited | Professional & scientific | 2007 |