| Cotswold Construction & Brickwork Limited | Construction | 2021 |
| Cotswolds Construction Ltd | Construction | 2019 |
| Cotsworld Ltd | Real estate | 2023 |
| Cottrell Consultancy Ltd | Professional & scientific | 2021 |
| Coturnix Cottages Ltd | Real estate | 2006 |
| Coturnix Management Limited | Households | 2020 |
| Count Beyond Ltd | Professional & scientific | 2025 |
| Country and Home Ltd | Wholesale & retail | 2014 |
| Country Buildings Protection Trust Limited | Health & social care | 1981 |
| Cowslip Comms Ltd | Professional & scientific | 2025 |
| Coxwell Garden Machinery Ltd | Wholesale & retail | 2020 |
| Crab Hill Developments Limited | Real estate | 2016 |
| Crabbe's Carpentry Limited | Manufacturing | 2020 |
| Crack the Ucat Ltd | Education | 2026 |
| Crane & Crane Ltd | Professional & scientific | 2025 |
| Crest Energy Limited | Administrative & support | 2019 |
| Crown Packaging Services Emea Limited | Administrative & support | 2023 |
| Croyde Medical Limited | Manufacturing | 2014 |
| Crux Investment Ltd | Real estate | 2025 |
| Cryon Limited | Extraterritorial | 2012 |
| Crystal Clean (Southern) Ltd | Administrative & support | 2002 |
| CS 2 Energy Limited | Extraterritorial | 2014 |
| CS Randhawa Enterprise Ltd | Extraterritorial | 2023 |
| CUBE3 Technologies Ltd | Information & communication | 2018 |
| Culham BUS Club Ltd | Transport & logistics | 2001 |
| Curtain Call Productions Limited | Information & communication | 2019 |
| CV Cleaning Services Ltd | Administrative & support | 2025 |
| CW Farm Vets LLP | | 2020 |
| CW Fork Trucks Ltd | Wholesale & retail | 2026 |
| CW Hendred Trustees Limited | Administrative & support | 2025 |
| Cybren Technology UK Limited | Information & communication | 2025 |
| D K Productions Ltd | Arts & recreation | 2018 |
| D&Y Trade Ltd | Wholesale & retail | 2024 |
| D'Angeli & SON Ltd | Construction | 2014 |
| D. G. Carpenter Limited | Construction | 1975 |
| D.W. Home & Office Improvements Limited | Construction | 1997 |
| DA Ledgers Ltd | Professional & scientific | 2025 |
| Damianos Ltd | Information & communication | 2017 |
| Dandelion Therapeutic Support Ltd | Education | 2024 |
| Dandridges Management Limited | Households | 2022 |
| Danedith Construction Services Ltd | Professional & scientific | 2023 |
| Danko Consulting Limited | Information & communication | 2023 |
| Darling Management Services Limited | Extraterritorial | 1998 |
| Dave Scott Haulage Limited | Administrative & support | 2006 |
| David Charles (Oxford) Limited | Professional & scientific | 2012 |
| Dawson Landscape Services Ltd | Administrative & support | 2023 |
| Daylight Procurement Limited | Professional & scientific | 2014 |
| DBA Creations Limited | Information & communication | 2017 |
| DC Designs (Oxon) Limited | Construction | 2025 |
| Debowy Properties Ltd | Real estate | 2025 |
| Deedee Events Ltd. | Other services | 2019 |
| Define Media Ltd | Professional & scientific | 2012 |
| Deisigh Ltd | Information & communication | 2022 |
| Delegant Limited | Administrative & support | 2011 |
| Delve Accounting Group Ltd | Professional & scientific | 2013 |
| Delve Accounting Ltd | Professional & scientific | 2010 |
| Demand Driven Network Ltd | Professional & scientific | 2022 |
| Deniz BBQ & Kebab Ltd | Hospitality | 2022 |
| Dews Meadow Farm Ltd | Agriculture & fishing | 2016 |
| Dewshore Ltd | Professional & scientific | 2020 |
| Dgfleming Ltd | Administrative & support | 2025 |
| Dickenson Consulting Ltd | Professional & scientific | 2023 |
| Digital Clockwork Ltd | Other services | 2006 |
| Digital Innovations IT Ltd | Information & communication | 2025 |
| Digitalis Computing Limited | Information & communication | 2014 |
| Dineen Project Planning & Asociados Ltd | Professional & scientific | 2014 |
| Dippers and Divers Ltd | Education | 2020 |
| DJ Paving Ltd | Construction | 2025 |
| DM Equine and Accountancy Ltd | Agriculture & fishing | 2025 |
| Doable Ltd | Real estate | 2006 |
| Dolphin Gallery Limited | Wholesale & retail | 2008 |
| Dolphin PM Limited | Administrative & support | 2015 |
| Don'T Step Back Ltd | Professional & scientific | 2024 |
| Dongsheng Limited | Wholesale & retail | 2025 |
| Dorado Holdings Ltd | Financial services | 2025 |
| DOT Dash Fitness Limited | Wholesale & retail | 2017 |
| Doublethebubbles Limited | Wholesale & retail | 2018 |
| Douglas and Simmons Ltd | Real estate | 2000 |
| Douglas and Simmons Property Sales Limited | Extraterritorial | 2016 |
| Douglas Design Partners Ltd | Professional & scientific | 2025 |
| Down to Earth Community Cafe CIC | Hospitality | 2021 |
| Downlander Events Limited | Information & communication | 2022 |
| Dproperty London Limited | Real estate | 2019 |
| DR Croker DRY EYE and Myopia Clinic Ltd | Health & social care | 2026 |
| Dragontek Automotive Ltd | Wholesale & retail | 2009 |
| Drecon Limited | Professional & scientific | 2011 |
| Dress'D Ltd | Hospitality | 2024 |
| Drey Productions Ltd. | Information & communication | 2015 |
| Dropshort Farm Management Company Limited | Households | 2017 |
| Ds&D Silver Services Ltd | Wholesale & retail | 2026 |
| DTL Groundworks and Building Ltd | Construction | 2018 |
| Dub-Line Automotive Ltd | Wholesale & retail | 2025 |
| Durbs Estates Limited | Real estate | 2023 |
| E.Bailey & SON (Footwear) Limited | Real estate | 1948 |
| Eadie Procurement Consultancy Ltd | Professional & scientific | 2013 |
| Earn Service Limited | Professional & scientific | 2023 |
| East Hendred Heritage Trust | Arts & recreation | 2002 |
| Easterfields Property Ltd | Real estate | 2025 |
| Edaphos Limited | Agriculture & fishing | 2005 |
| EJ Henson Ltd | Professional & scientific | 2016 |