| Cross Solution Consulting Limited | Professional & scientific | 2023 |
| Croxon Consulting Ltd | Professional & scientific | 2015 |
| Csld Ltd | Arts & recreation | 2024 |
| CSR With Purpose Limited | Professional & scientific | 2025 |
| Csuite Ltd | Professional & scientific | 2025 |
| CTP Limited | Administrative & support | 2025 |
| Cu-Kitchens Limited | Construction | 2016 |
| Custom Karate Limited | Education | 2009 |
| Cuttlebrook Consulting Limited | Professional & scientific | 2021 |
| Cyan Developments Ltd | Construction | 2016 |
| Cyber Commercial Systems Limited | Professional & scientific | 2013 |
| Cyber Marine Systems Limited | Professional & scientific | 2013 |
| Cyberhomes Ltd | Information & communication | 2004 |
| Cyberlounge Limited | Construction | 2024 |
| D & N Farming Ltd | Agriculture & fishing | 2023 |
| D a Strategic Ltd | Professional & scientific | 2003 |
| D H Speer Ltd | Construction | 2024 |
| D P Bespoke Joinery Limited | Manufacturing | 2026 |
| D Stone Interiors Limited | Construction | 2016 |
| D Tapping Building & Decorating Ltd | Construction | 2018 |
| D2 Healthcare LLP | | 2019 |
| D8R Group Ltd | Information & communication | 2026 |
| Daniel Camp French Polishing Ltd | Other services | 2020 |
| Daniel Williams Coaching Ltd | Arts & recreation | 2025 |
| Dapway Ltd | Health & social care | 2021 |
| Darwish Limited | Construction | 2022 |
| Data Laser Mail Holdings Limited | Professional & scientific | 2015 |
| Data Laser Mail Limited | Manufacturing | 1999 |
| Data Luminescence Limited | Information & communication | 2003 |
| Datastream Performance Ltd | Manufacturing | 2026 |
| Daybase Ltd | Information & communication | 2026 |
| DCO Projects Limited | Construction | 2026 |
| DE Leon Associates Limited | Other services | 2020 |
| Deasy Management Limited | Construction | 2011 |
| Decoglaze Limited | Construction | 2000 |
| Delta T Heating Engineers Ltd | Construction | 2022 |
| Deltatrax Limited | Construction | 2003 |
| Department XII Ltd | Professional & scientific | 2020 |
| Design Engineering Studio Limited | Professional & scientific | 2022 |
| Designed Blue Ltd | Information & communication | 2015 |
| Designit Limited | Information & communication | 2011 |
| Devcomms (East) Limited | Professional & scientific | 2024 |
| Devcomms (Midlands) Limited | Professional & scientific | 2024 |
| Devcomms (South East) Limited | Professional & scientific | 2024 |
| Devcomms (South West) Limited | Professional & scientific | 2024 |
| Devcomms Holdings Limited | Financial services | 2024 |
| Development Communications Limited | Professional & scientific | 2017 |
| Devey Tree Care Limited | Administrative & support | 2017 |
| DF Technology Consulting Limited | Information & communication | 2015 |
| Diagnostic Reagents Holdings Limited | Financial services | 2024 |
| Diagonal Works Ltd | Information & communication | 2019 |
| Diamond Microwave Devices Limited | Manufacturing | 2006 |
| Diamond Microwave Holdings Limited | Manufacturing | 2012 |
| Digital Ace Limited | Information & communication | 2011 |
| Digital-Zest Online Limited | Information & communication | 2010 |
| DIN Properties Ltd | Real estate | 2021 |
| Ding Learning Limited | Education | 2020 |
| Dioptric Limited | Arts & recreation | 2022 |
| Dipole Systems Ltd | Professional & scientific | 2024 |
| Direct Connect Logistics Limited | Transport & logistics | 2014 |
| Disco Seafood Co Limited | Agriculture & fishing | 2024 |
| Discover Careers Ltd | Information & communication | 2025 |
| Distinctive Resins Limited | Construction | 2018 |
| Ditto Publishing Ltd | Information & communication | 2016 |
| Diverse Digital Marketing Ltd | Administrative & support | 2016 |
| DJS Strategic Limited | Professional & scientific | 2025 |
| DKN Jamm Ltd | Professional & scientific | 2019 |
| DMC (GB) Limited | Construction | 2013 |
| DMD Electrical Installations Limited | Construction | 2016 |
| DNA Builders Property Ltd | Real estate | 2017 |
| Doctor-Jo Limited | Health & social care | 2024 |
| Doff Headwear & Accessories Limited | Wholesale & retail | 2018 |
| Dog Shaped Ltd | Wholesale & retail | 2021 |
| Dogspawn.Net Limited | Information & communication | 2026 |
| Doig Furniture Limited | Manufacturing | 2013 |
| Doig Property Ltd | Construction | 2024 |
| Donald Projects Ltd | Professional & scientific | 2021 |
| Done Ready Limited | Administrative & support | 2011 |
| Dopamyn Limited | Information & communication | 2025 |
| Dorchester Sailing Club | Arts & recreation | 2001 |
| Dorene Properties Limited | Households | 1963 |
| Dormers Leys Tetsworth Limited | Real estate | 2016 |
| DOS Cucharas Limited | Information & communication | 2015 |
| Dough & Co Street Food Ltd | Hospitality | 2025 |
| Dovecote Holdings Limited | Professional & scientific | 2019 |
| DPB Geology Ltd | Professional & scientific | 2020 |
| DR Eleanor Wicks Ltd | Education | 2024 |
| DR P Nair Limited | Health & social care | 2016 |
| Drifter Drinks Ltd | Wholesale & retail | 2026 |
| Driven 2 Pass Limited | Other services | 2015 |
| Drom UK Limited | Construction | 2002 |
| Drunkenthaichef Ltd | Hospitality | 2023 |
| Dufva Barreca Design Ltd | Professional & scientific | 2018 |
| Dulursa Ltd | Professional & scientific | 2026 |
| Dunnock Ltd | Professional & scientific | 2018 |
| DW Live Music LLP | | 2019 |
| E & O Operators Limited | Administrative & support | 2019 |
| E & O Properties Limited | Real estate | 2022 |
| E-Sourcing Ltd | Administrative & support | 2020 |
| E4S Recruitment Ltd | Information & communication | 2020 |