| Corellian Engineering Ltd | Information & communication | 2022 |
| Corinth International Limited | Mining & quarrying | 2025 |
| Cornerstone PHE Ltd | Construction | 2018 |
| Cornerstone Staffing Solutions Ltd | Administrative & support | 2020 |
| Cornfield Bakery Limited | Manufacturing | 2003 |
| Cornfield Holdings Limited | Financial services | 2025 |
| Correia & Co (UK) Limited | Wholesale & retail | 2018 |
| Corriculo Ltd | Administrative & support | 2013 |
| Corroborum Limited | Professional & scientific | 2013 |
| Cortex Organics Limited | Manufacturing | 2018 |
| Cory Consult Limited | Professional & scientific | 2010 |
| Cory Limited | Construction | 2004 |
| Cosma Sales Limited | | 1982 |
| Cosma Technical Services Limited | | 1981 |
| Cosmetatou Consulting Ltd | Professional & scientific | 2021 |
| Cosmo Medical Services Limited | Health & social care | 2024 |
| Cotek Engineering Limited | Professional & scientific | 2003 |
| Cotswold HR Ltd | Administrative & support | 2018 |
| Cotswold Lodge Hotel Limited | Hospitality | 2019 |
| Cotswold Mist Ltd | Information & communication | 2022 |
| Cotswold Plastic Surgery Limited | Health & social care | 2015 |
| Cotswold Press Ltd | Information & communication | 2006 |
| Cotswold Reclamation Co. Limited | Wholesale & retail | 1994 |
| Cotswold Single PLY Limited | Construction | 2021 |
| Cotswold Time Company Limited | Wholesale & retail | 2022 |
| Cotswold Vehicle Recovery (Swindon) Limited | Transport & logistics | 2019 |
| Cotswolds Barbers Limited | Other services | 2023 |
| Cotswolds Secure Storage Limited | Transport & logistics | 2024 |
| Cotswolds Yoga Ltd | Education | 2024 |
| Cotswoldspurecare Ltd | Health & social care | 2026 |
| Cottee Meldrum Limited | Professional & scientific | 2003 |
| Coulson Productions Ltd | Information & communication | 2023 |
| Counselling Carers C.I.C. | Health & social care | 2021 |
| Courier Branch Ltd | Transport & logistics | 2025 |
| Courier Serviceds Limted Limited | Transport & logistics | 2025 |
| Court Place Farm Allotments Community Interest Company | Agriculture & fishing | 2021 |
| Courtlands Wealth Planning Ltd | Financial services | 2017 |
| Courtside Hillsborough CIC | Arts & recreation | 2022 |
| Courtside Hubs CIC | Arts & recreation | 2015 |
| Courtside Witney C.I.C. | Arts & recreation | 2026 |
| Courtyards Maintenance Company Limited | Households | 2021 |
| Cover Drive Cricket Ltd | Information & communication | 2021 |
| Covered Market Souvenirs Ltd | Wholesale & retail | 2025 |
| Covert Close Limited | Households | 2021 |
| Cowgill & Associates Ltd. | Professional & scientific | 2016 |
| Cowley Climate Collective Community Interest Company | Education | 2023 |
| Cowley Express Ltd | Wholesale & retail | 2021 |
| Cowley Halal Meat and Groceries Ltd | Wholesale & retail | 2021 |
| Cowley Khyber Kebab House Ltd | Hospitality | 2019 |
| Cowley Mini Mart Limited | Wholesale & retail | 2025 |
| Cowley Properties Ltd | Real estate | 2022 |
| Cowley Road Studios Ltd | Manufacturing | 2024 |
| Cowley Road Works | Education | 2007 |
| Cowleyfornia Studios LLP | | 2020 |
| COX Hinkins & Co. Limited | Professional & scientific | 1991 |
| COX Hinkins Audit Services Limited | Professional & scientific | 2020 |
| Coxeters,Limited | Real estate | 1951 |
| Cozy Home Home Improvements Limited | Administrative & support | 2024 |
| CP Advisory (Europe) Limited | Professional & scientific | 2022 |
| CP Oxford Limited | Professional & scientific | 2024 |
| CP1 Associates Limited | Manufacturing | 2011 |
| Cpabritiscounci.Qualification. UK Limited | Professional & scientific | 2025 |
| CPD Oxford Ltd | Education | 2023 |
| CPR Walker Limited | Health & social care | 2012 |
| CPT Tutors Ltd. | Education | 2010 |
| Crabtree Yummy Limited | Hospitality | 2025 |
| Cradle Comfort Ltd | Health & social care | 2025 |
| Crafty Belle Ltd | Hospitality | 2018 |
| Craig Holloway Electrical Limited | Construction | 2011 |
| Craijine Limited | Real estate | 1980 |
| Crawford Bond Architects Ltd | Professional & scientific | 2008 |
| Crawford Developers Limited | Construction | 2022 |
| Crazy Goose Productions Ltd | Information & communication | 2018 |
| Crazy Mango Properties Limited | Real estate | 2004 |
| Crazycleans Ltd | Administrative & support | 2020 |
| Create Change Coaching Ltd | Health & social care | 2022 |
| Creation Theatre Ltd | Arts & recreation | 2007 |
| Creations Paint Limited | Construction | 2014 |
| Creative Data Limited | Information & communication | 2002 |
| Creative Driveways Patios Paving Landscaping Ltd | Administrative & support | 2025 |
| Creative E-Com Ltd | Wholesale & retail | 2025 |
| Creative Fine Art Ltd | Wholesale & retail | 2014 |
| Creative Oak Buildings Limited | Construction | 2013 |
| Creative Reset Collective Ltd | Education | 2025 |
| Creative Web Technologies Limited | Information & communication | 2015 |
| Creatives Ledger Ltd | Professional & scientific | 2024 |
| Creator Property Ltd | Real estate | 2025 |
| Creditnature Ltd | Professional & scientific | 2021 |
| Credo Therapies Ltd | Health & social care | 2022 |
| Credo Youth Ltd | Education | 2025 |
| Creebray Limited | Construction | 1981 |
| Crescent Farms Limited | Manufacturing | 2025 |
| Crescent Plastering Limited | Construction | 2025 |
| Crescent Road Garage Limited | Wholesale & retail | 2005 |
| Cresco Legal Limited | Professional & scientific | 2010 |
| Creston Consulting Ltd | Professional & scientific | 2025 |
| Crewquarters Limited | Hospitality | 2008 |
| Crick Estates Ltd | Real estate | 2026 |
| Crighton Consulting Ltd | Professional & scientific | 2024 |
| Crisp Creative Limited | Professional & scientific | 2011 |