| Bright EYE Deer Marketing Ltd | Administrative & support | 2019 |
| Broadbent Enterprises Limited | Information & communication | 2010 |
| Brooklane Creative Limited | Professional & scientific | 2021 |
| C & D (Olney) Limited | Real estate | 2009 |
| Cara Capsules Ltd | Manufacturing | 2020 |
| CARE2ASSESS Limited | Health & social care | 2020 |
| Casa Bella Industries S.A. Limited | Extraterritorial | 2009 |
| Case Group (Holdings) 2024 Limited | Administrative & support | 2024 |
| Case Group (Holdings) Limited | Administrative & support | 2009 |
| Case Ltd | Administrative & support | 1997 |
| Case Security Ltd | Professional & scientific | 1997 |
| Cedar Campervans Ltd | Wholesale & retail | 2021 |
| Certainsun Limited | Real estate | 1988 |
| Certainsun Properties Limited | Real estate | 2022 |
| CFS Wealth Planning Limited | Financial services | 2019 |
| Chase Park Investments Limited | Real estate | 2014 |
| Cheese on Towcest' Ltd | Wholesale & retail | 2024 |
| Cheri Nails Spa Ltd | Other services | 2024 |
| Cherry Steps Ltd | Information & communication | 2018 |
| Chiltern Thrust Bore Holdings Ltd | Financial services | 2020 |
| Chiltern Thrust Bore Ltd. | Construction | 1994 |
| Chris Page Services Ltd. | Other services | 1997 |
| Christolite Ltd | Information & communication | 2007 |
| Circalium Limited | Water & waste | 2025 |
| Classy Nails 33 Ltd | Other services | 2024 |
| Claydon Oakgrove Limited | Health & social care | 2015 |
| Clickers Yard Court Management Company Ltd | Households | 2019 |
| Clockwork Project Solutions Ltd | Financial services | 2008 |
| Codetta Consulting Ltd | Information & communication | 2018 |
| Coleman Car Sales Limited | Wholesale & retail | 2022 |
| Coleman Terraview Ltd | Professional & scientific | 2026 |
| Colin Banks Art Ltd | Arts & recreation | 2019 |
| Company AS Limited | Real estate | 2014 |
| Complete Financial Services Limited | Financial services | 2002 |
| Complete Roofing Repairs Ltd | Construction | 2025 |
| Conservation Leadwork Limited | Construction | 2008 |
| Control Group Interiors Limited | Administrative & support | 2017 |
| Coomber Consultancy Ltd | Construction | 2024 |
| Coowar Consultancy Ltd | Professional & scientific | 2019 |
| Cormach Engineering Limited | Professional & scientific | 2022 |
| Cottage Management Limited | Real estate | 2000 |
| Counter-Act Systems Limited | Administrative & support | 1997 |
| Country & Stable Limited | Extraterritorial | 2013 |
| Country & Stable of Olney Limited | Wholesale & retail | 2012 |
| Cowper Works Management Company Limited | Real estate | 2000 |
| Crafted by ROE Ltd | Wholesale & retail | 2023 |
| Cricketers Close Stewkley Management Company Limited | Real estate | 2019 |
| Crossin Plasterers Property Services Ltd | Construction | 2019 |
| Crushed Ice Group Limited | Financial services | 2026 |
| Crushed Ice Limited | Information & communication | 2003 |
| CUB & Co Hub Limited | Health & social care | 2024 |
| Cube Systems Limited | Information & communication | 2026 |
| Curious Crow Limited | Professional & scientific | 2024 |
| Cutcrew Ltd | Administrative & support | 2020 |
| Dariana Maderer Ltd | Hospitality | 2025 |
| Darren Osborne Decorators Limited | Construction | 2023 |
| Dass Designs Limited | Professional & scientific | 2024 |
| David Coles Architects Limited | Professional & scientific | 2003 |
| David Pibworth Stage Hire Limited | Administrative & support | 2020 |
| DCA Holdings Limited | Financial services | 2025 |
| DDA Access Ltd | Administrative & support | 2003 |
| DECEMBER12 Ltd | Wholesale & retail | 2013 |
| Deep Dish Beach Academy Ltd | Arts & recreation | 2019 |
| Deep Dish Beach Home Ltd | Arts & recreation | 2021 |
| Deep Dish Beach Ltd | Arts & recreation | 2017 |
| Delalim Barber Ltd | Other services | 2026 |
| Delujo Home Ltd | Wholesale & retail | 2025 |
| Design by Art Limited | Professional & scientific | 2016 |
| Detail Squared Consulting Limited | Professional & scientific | 2017 |
| Digipro Ltd | Information & communication | 2024 |
| Digital Data & Technology Limited | Information & communication | 2019 |
| Digs Limited | Real estate | 2017 |
| Dinglederry Management Company Limited | Households | 2015 |
| DIP Products Limited | Wholesale & retail | 2023 |
| Direct Site Solutions Ltd | Professional & scientific | 2016 |
| Disrupt Learning and Education Services Limited | Professional & scientific | 2016 |
| Diversity People Ltd | Administrative & support | 2025 |
| Doff's Field Limited | Arts & recreation | 2022 |
| Dokonale Finance SRO Ltd | Wholesale & retail | 2004 |
| Domesticats Limited | Other services | 2015 |
| Donzella Ltd | Hospitality | 2021 |
| Donzella Services Ltd | Real estate | 2022 |
| Doughty Works Ltd | Wholesale & retail | 2025 |
| Dragek Project Management Limited | Professional & scientific | 2016 |
| Dragon Wheels Restorations Limited | Professional & scientific | 2014 |
| Dreamville Limited | Professional & scientific | 2018 |
| Ducksworth Developments Limited | Real estate | 2016 |
| Dunkley Property Services Limited | Real estate | 2022 |
| Dwkt Limited | Financial services | 2020 |
| E-Motiv Shift Systems Limited | Manufacturing | 2026 |
| Eagles HR Limited | Administrative & support | 2025 |
| Eames Livermore Consulting Limited | Professional & scientific | 2023 |
| EAST40 Solutions Ltd | Construction | 2023 |
| Ecurie Bertelli Limited | Manufacturing | 1994 |
| Ecurie Forte Ltd | Wholesale & retail | 2024 |
| Ecurie Investments Ltd | Financial services | 2024 |
| ED LEE Photographer Limited | Professional & scientific | 2009 |
| Edge Events Group Ltd | Hospitality | 2021 |
| Effective Training & Consultancy Limited | Professional & scientific | 1998 |
| Emma Frazier Wellness Ltd | Health & social care | 2023 |