| Cheese From Britain Limited | Wholesale & retail | 2000 |
| Chelerty Limited | Construction | 2004 |
| Cheltenham and Cotswold Care Limited | Health & social care | 2025 |
| Chequers Court (Salisbury) Management Company Limited | Households | 1987 |
| Chieftain Private Property LLP | | 2021 |
| Child Scaffolding Limited | Construction | 2003 |
| Chris Fell and Associates Ltd | Professional & scientific | 2014 |
| Chrisgate Holdings Limited | Real estate | 1971 |
| Chrisgate Limited | Real estate | 1973 |
| Chthonics Limited | Information & communication | 1997 |
| Cimco Integration Limited | Information & communication | 2007 |
| City Lifestyles Limited | Real estate | 2007 |
| CJ Electrical Installations Limited | Manufacturing | 2007 |
| Clara Invest Ltd | Information & communication | 2000 |
| Classical Renaissance Limited Partnership NO.1 | | 2007 |
| Classical Renaissance Limited Partnership NO.2 | | 2007 |
| Clement Programming & Analyst Limited | Professional & scientific | 1985 |
| Clever Software Group Limited | Information & communication | 2016 |
| Clifford FRY & Co. (Payroll) Ltd. | Administrative & support | 2002 |
| Clifford-Bonney | | 1983 |
| Codford Builders Limited | Construction | 1972 |
| Coetmor Properties Ltd | Real estate | 2006 |
| Colin Bush Machinery Limited | Wholesale & retail | 2007 |
| Comfyfloor Systems Limited | Construction | 1997 |
| Community-Web Limited | Professional & scientific | 1999 |
| Compubarn Limited | Agriculture & fishing | 1985 |
| Cook Roofing Limited | Construction | 2005 |
| Cool 18 Air Conditioning Ltd | Other services | 2007 |
| Coombe Castle Holdings Limited | Financial services | 2023 |
| Cooper-Avon Tyres Pension Trust Limited | Other services | 1997 |
| Coppins of Corsham Limited | Wholesale & retail | 2001 |
| Corvus Travel Ltd | Transport & logistics | 2003 |
| Coryndon Limited | Manufacturing | 2003 |
| Counties | Other services | 1972 |
| COX & Hall Limited | Construction | 2002 |
| Cross Street Garage (Swindon) Limited | Wholesale & retail | 2006 |
| Crosslanes Associates Limited | Professional & scientific | 2007 |
| CSL Properties Limited | Real estate | 2003 |
| Cutler and Cashin Limited | Wholesale & retail | 2002 |
| D & R Randall Limited | Construction | 2004 |
| D W Oliver Tree Services Ltd | Agriculture & fishing | 2007 |
| D'Essence Ltd | Health & social care | 2023 |
| Danaron Limited | Information & communication | 1997 |
| Darack Enterprises Limited | Professional & scientific | 2002 |
| Darren Freeth Roofing Contractor Limited | Construction | 2006 |
| Data Services Limited | Professional & scientific | 1991 |
| Datamec Software Limited | Information & communication | 2004 |
| Dauwalder's (Stamp Dealers) Limited | Administrative & support | 1997 |
| David Jarvis Associates Limited | Professional & scientific | 1989 |
| David Owen Accountants Limited | Professional & scientific | 2006 |
| Dawndale Limited | Construction | 1978 |
| Dc&P Associates Limited | Construction | 2007 |
| Derrick C Potter Limited | Construction | 2006 |
| Derrick Newman Limited | Professional & scientific | 2002 |
| Devizes and District Opportunity Centre | Health & social care | 1992 |
| Devizes Fine Kitchens Ltd | Manufacturing | 2003 |
| Diamer UK Ltd | Wholesale & retail | 2020 |
| Diffusion Hair Design Ltd | Other services | 2004 |
| Dividual Investments Limited | Professional & scientific | 1964 |
| DMC Auto Engineers Limited | Wholesale & retail | 2007 |
| DNC Electronics Limited | Manufacturing | 1997 |
| DON Rogers (Swindon) Limited | Wholesale & retail | 1968 |
| Donsound Limited | Arts & recreation | 1988 |
| Dontha Services Ltd | Information & communication | 2022 |
| Dorothy House | Health & social care | 1978 |
| DPS Property Management Limited | Real estate | 2003 |
| DPS Relocation Ltd | Administrative & support | 2002 |
| Dreamnight Limited | Professional & scientific | 1946 |
| DRH Electrical Services Limited | Construction | 2006 |
| DTW Consultants Ltd. | Professional & scientific | 2005 |
| Dynamatic Limited | Manufacturing | 2007 |
| Dyson Estates Limited | Administrative & support | 2004 |
| Dyson Exchange Limited | Manufacturing | 2004 |
| Dyson Finance Limited | Manufacturing | 2007 |
| Dyson International Limited | Manufacturing | 1991 |
| Dyson Limited | Manufacturing | 1991 |
| Dyson Overseas Distribution Limited | Manufacturing | 2007 |
| Dyson Technology Limited | Manufacturing | 1985 |
| Dyson UK Holdings Limited | Manufacturing | 1999 |
| E-Quant Ltd | Professional & scientific | 2007 |
| E.& S.Shops Limited | Wholesale & retail | 1964 |
| E.J. Shanley & SON (Trowbridge) Limited | Water & waste | 1965 |
| Eagle OWL Consulting Limited | Professional & scientific | 2024 |
| Earthline Developments Limited | Construction | 2017 |
| Earthwise Garden Design Limited | Administrative & support | 2004 |
| Earthworks Wilts Limited | Construction | 2004 |
| Easi-Gro Limited | | 1987 |
| Easterbrook Restoration Services Ltd | Financial services | 2021 |
| Easterton Vehicles Limited | Wholesale & retail | 2002 |
| Eastpound Limited | Information & communication | 1992 |
| Edge Digital Limited | Professional & scientific | 2007 |
| Edris Ataie Ltd | Professional & scientific | 2025 |
| Edward and Alan Limited | Construction | 1983 |
| EFA Training Limited | Education | 2004 |
| Eflame Ltd | Information & communication | 2007 |
| Eldene (Swindon) Community Association Ltd | Arts & recreation | 1996 |
| Emma Hipwood Ltd | Households | 2024 |
| Emma Turk Design Solutions Limited | Administrative & support | 2008 |
| Enactiq Ltd | Information & communication | 2019 |
| END to END Improvement Ltd | Professional & scientific | 2017 |