| CSC Callington Limited | Transport & logistics | 2011 |
| CSF Holdings (Plymouth) Ltd | Real estate | 2025 |
| CSH Technologies Limited | Administrative & support | 2016 |
| Csjp Solutions Ltd | Wholesale & retail | 2025 |
| CSM Heating SW Ltd | Construction | 2018 |
| Cspm Cleaning Solutions Ltd | Transport & logistics | 2024 |
| CST Real Estate Ltd | Real estate | 2021 |
| CSV Worldwide Logistics Company Limited | Transport & logistics | 2025 |
| Ctsw Skills Ltd | Education | 2018 |
| Cuba Bar Ltd | Hospitality | 2021 |
| Cubkind Ltd | Wholesale & retail | 2022 |
| Cuda Drinks Co. Limited | Wholesale & retail | 2007 |
| Cuestudio Ltd | Information & communication | 2025 |
| Cuiyuan Limited | Hospitality | 2018 |
| Cumberland Park Gardens Management Limited | Households | 1993 |
| Cumming Computing Ltd | Information & communication | 2026 |
| Cupcake Coffee Box Ltd | Hospitality | 2013 |
| CUR8 Edition Ltd | Real estate | 2023 |
| Curacasa Ltd | Health & social care | 2026 |
| Curadh Limited | Health & social care | 2019 |
| Curious Carpentry Ltd | Construction | 2023 |
| Curious Hair Ltd | Other services | 2021 |
| Curlew Mews Management Co. Limited | Households | 2000 |
| Curly GAZ Eats Ltd | Information & communication | 2024 |
| Curnows Cafe Ltd | Hospitality | 2026 |
| Currycorp Ltd | Hospitality | 2018 |
| Curwins Financial & Mortgage Advisers Ltd | Financial services | 2012 |
| Custard Architecture Limited | Professional & scientific | 2006 |
| Custodian Picture Framers Limited | Information & communication | 2020 |
| Custom Classic Components Ltd | Manufacturing | 2024 |
| Custom Creative Plymouth Ltd | Manufacturing | 2026 |
| Custom Decorating and Property Maintenance South West Limited | Construction | 2021 |
| Custom Fluid Power Ltd | Professional & scientific | 2005 |
| Custom Welding Limited | Manufacturing | 2024 |
| Cutec Ltd | Information & communication | 1999 |
| Cutlass Mechanical Engineering Limited | Manufacturing | 2007 |
| Cutlers Hotel (2025) Ltd | Hospitality | 2025 |
| Cutter & Co Financial Planning Limited | Financial services | 2018 |
| Cutting Edge (SW) Ltd | Other services | 2021 |
| Cutting Edge Barber Plymouth Ltd | Other services | 2016 |
| Cuttlebone Limited | Real estate | 2016 |
| Cutzz Styles Barbers Limited | Other services | 2013 |
| CWA (SW) Limited | Professional & scientific | 2026 |
| Cwmh Branding Ltd | Extraterritorial | 2024 |
| CWS (SW) Ltd | Administrative & support | 2022 |
| CWS Heating & Plumbing Ltd | Construction | 2023 |
| CX Freehold Limited | Real estate | 2014 |
| Cyantronic Technology Limited | Professional & scientific | 2021 |
| Cyber Systems Europe Ltd | Information & communication | 2025 |
| Cyber X Ltd | Extraterritorial | 2015 |
| Cyberdelic (South West) Limited | Information & communication | 2021 |
| Cyderhouse Co. Limited | Hospitality | 2022 |
| CYI Limited | Hospitality | 2020 |
| CYM Services Limited | Health & social care | 2023 |
| CYN UK Limited | Transport & logistics | 2015 |
| Cyphex Limited | Information & communication | 2025 |
| D & a Jones Limited | Financial services | 2021 |
| D & E Xclusive Motors Limited | Wholesale & retail | 2026 |
| D & N Plumbing & Heating Engineers Limited | Construction | 2003 |
| D & W Auto Services Ltd | Wholesale & retail | 2016 |
| D a Lowman Ltd | Wholesale & retail | 2026 |
| D and M Lets Ltd | Real estate | 2024 |
| D and R Sales Limited | Wholesale & retail | 2015 |
| D Boucher Holdings Ltd | Real estate | 2022 |
| D C Pipefitters (S W) Limited | Construction | 2014 |
| D Clark Inspection Services Ltd | Professional & scientific | 2023 |
| D Critchell Management Services Limited | Other services | 2015 |
| D Crosby Limited | Construction | 2016 |
| D Distin Ltd | Real estate | 2025 |
| D F S Developments Ltd | Real estate | 2014 |
| D Farnham Electrical Contractors Ltd | Construction | 2012 |
| D G Care Ltd | Health & social care | 2014 |
| D J Curtis & SON Limited | Construction | 2009 |
| D J Interiors SW Ltd | Wholesale & retail | 2007 |
| D Jeffery Groundworks & Utilities Ltd | Construction | 2021 |
| D K Drylining (South West) Limited | Construction | 2020 |
| D L Decorators SW Limited | Construction | 2018 |
| D Moore (SW) Ltd | Real estate | 2025 |
| D P Boiler Repairs Ltd | Construction | 2012 |
| D P Bricklayers Ltd | Construction | 2022 |
| D P S Theatrical Technical Services Ltd | Construction | 2007 |
| D S Batteries Ltd | Manufacturing | 2009 |
| D W Brickworks Limited | Construction | 2015 |
| D W Landscaping and Groundworks Limited | Construction | 2020 |
| D&C Auto Repairs Limited | Wholesale & retail | 2013 |
| D&C Renovations SW Ltd | Manufacturing | 2024 |
| D&D Thatching Ltd | Construction | 2022 |
| D&M Construction SW Ltd | Construction | 2024 |
| D&M Holdings SW Ltd | Professional & scientific | 2025 |
| D-Service 16 Ltd | Information & communication | 2016 |
| D. Cory Plumbing and Heating Limited | Construction | 2002 |
| D. R. Holdings Ltd | Financial services | 2020 |
| D.A.Tubb Limited | Wholesale & retail | 1961 |
| D.C Building & Carpentry Ltd | Construction | 2026 |
| D.C. Builders and Contractors Ltd | Construction | 2015 |
| D.F.R. Roofing Limited | Construction | 1997 |
| D.J.P. Heating Ltd | Construction | 2016 |
| D.J.R Journey to Success Ltd | Professional & scientific | 2023 |
| D.Mann Electrical Ltd | Construction | 2023 |
| D.S.C. (Stourbridge) Limited | Wholesale & retail | 2012 |