| Cressex Road Management Company Limited | Households | 2006 |
| Crest Estate Developments Limited | Construction | 2020 |
| Crest Estate Developments Rental Limited | Real estate | 2025 |
| Creverartis Limited | Information & communication | 2018 |
| Crew Coaching Limited | Arts & recreation | 2006 |
| Cristo Design Limited | Other services | 2017 |
| Critically Endangered Socks | Wholesale & retail | 2017 |
| Crook Holdings Ltd | Financial services | 2024 |
| Crowdsource Limited | Administrative & support | 2012 |
| Crown Fruit Ltd | Wholesale & retail | 2022 |
| CRS Associates (UK) Limited | Professional & scientific | 1999 |
| CRS Properties (Marlow) Ltd | Real estate | 2014 |
| Crust Stop Ltd | Hospitality | 2026 |
| CS Longley Finance Ltd | Professional & scientific | 2025 |
| Csct Limited | Administrative & support | 2025 |
| CSE (Engineering) Limited | Professional & scientific | 2022 |
| Cudlipp Limited | Health & social care | 2025 |
| Culden FAW Estate Limited | Agriculture & fishing | 2019 |
| Culden FAW Limited | Construction | 2007 |
| Cultural Calculator Ltd | Information & communication | 2018 |
| Culturevolution Ltd | Administrative & support | 2024 |
| Curtis House Management Company Limited | Households | 2017 |
| CUT Holdings Limited | Financial services | 2018 |
| Cybermorphic Systems Ltd | Professional & scientific | 2011 |
| Cōntor Aesthetics Limited | Health & social care | 2026 |
| D&B Henley Ltd | Professional & scientific | 2023 |
| D. Frearson & SON Limited | Wholesale & retail | 2005 |
| D.B.J. Auto-Electrical Limited | Professional & scientific | 1979 |
| D.J.Dawes(Farms)Limited | Agriculture & fishing | 1963 |
| D.W.B Property Limited | Real estate | 2017 |
| D.W.B Wealth Limited | Financial services | 2017 |
| D23 Consulting Ltd | Professional & scientific | 2025 |
| Daceberry Court Management Company Limited | Households | 1998 |
| Dadley Investments Limited | Financial services | 2024 |
| Dane & Dutch Ltd | Information & communication | 2011 |
| Danzak Limited | Wholesale & retail | 2005 |
| Darcey House Residence Freehold Management Ltd | Households | 2024 |
| Darke Music Management Limited | Real estate | 2014 |
| Darkside Logic (One) Ltd | Professional & scientific | 2015 |
| Dashwood Investments Limited | Real estate | 2003 |
| Data Zest Limited | Professional & scientific | 2025 |
| Dave Hamilton-Green Limited | Information & communication | 2010 |
| David Abra Limited | Professional & scientific | 2023 |
| David Bray Motor Engineers Limited | Wholesale & retail | 2009 |
| David James Plant Based Ltd | Manufacturing | 2021 |
| Davidsons Independent Financial Advisers Limited | Administrative & support | 2002 |
| Davidsons Portfolio Management Ltd | Financial services | 2017 |
| Davies Hickman Partners Limited | Professional & scientific | 2007 |
| Davis Creative Ltd | Information & communication | 2019 |
| DCH Mallorca Limited | Real estate | 2012 |
| Dean Court Road Limited | Households | 2007 |
| Deanclose Properties Limited | Households | 1999 |
| Debug Limited | Extraterritorial | 2002 |
| Decarb Consult Ltd | Professional & scientific | 2024 |
| Decisional Point Limited | Information & communication | 2022 |
| Decorating Elements Ltd | Construction | 2017 |
| Defence Maritime Technology Works Ltd | Information & communication | 2026 |
| Delegate Limited | Administrative & support | 1987 |
| Denehy Connection Ltd | Professional & scientific | 2013 |
| Destor.One Ltd | Information & communication | 2022 |
| Devil in the Detail Limited | Professional & scientific | 2012 |
| Dgbt Ltd | Other services | 2018 |
| DGN Building Services Limited | Construction | 2016 |
| DHD Commercial Ltd | Construction | 2015 |
| Dicentra Design Ltd | Information & communication | 2020 |
| Didcot Glazing & Window Centre Limited | Manufacturing | 2015 |
| Digital 1 Consulting Limited | Administrative & support | 2017 |
| Digital Transformation Partnership Ltd | Professional & scientific | 2009 |
| Dilwyn Court (Freehold) Limited | Households | 2015 |
| Dilwyn Court Residents Association Limited | Households | 1986 |
| Dimedium UK Limited | Extraterritorial | 2008 |
| Dineromob UK Ltd | Wholesale & retail | 2012 |
| Discova Ltd | Information & communication | 2013 |
| Distributed Energy Solutions Limited | Energy | 2024 |
| Diving Station 2015 Limited | Manufacturing | 2016 |
| Dlssc Solutions Limited | Other services | 2015 |
| DMR Bespoke Projects Ltd | Administrative & support | 2025 |
| Dobl Ltd | Information & communication | 2025 |
| Docendo Group Limited | Financial services | 2025 |
| Doghouse Productions Ltd | Information & communication | 2024 |
| Doktor Window Limited | Construction | 2017 |
| Dolphin House RTM Company Limited | Households | 2023 |
| Donal Murray Limited | Transport & logistics | 2002 |
| Dorchester MOT Centre Limited | Professional & scientific | 2025 |
| Dougal Sadler Limited | Professional & scientific | 2022 |
| Downham Hill Limited | Professional & scientific | 2016 |
| Downs Stables Management Company Limited | Households | 2012 |
| DPS Surveys Ltd | Professional & scientific | 2014 |
| DR Galyna Limited | Other services | 2024 |
| DR House Services Ltd | Administrative & support | 2016 |
| DR Jclb Practice Limited | Health & social care | 2024 |
| DR Thornton Aesthetics Ltd | Health & social care | 2025 |
| DR. Window Limited | Construction | 2017 |
| Draper Lang LLP | | 2012 |
| Drays Residents Management Limited | Professional & scientific | 2012 |
| Drommedaris Limited | Transport & logistics | 2024 |
| Drumlab Ltd | Education | 2020 |
| DS Building Consultancy Limited | Professional & scientific | 2022 |
| Dsdb Limited | Wholesale & retail | 2025 |
| DTA Solutions Ltd | Other services | 2026 |