| Comptons Limited | Other services | 1988 |
| Conkaa Holdings Ltd | Financial services | 2025 |
| Conkaa Limited | Information & communication | 2016 |
| Conor O'Farrell Racing Ltd | Arts & recreation | 2014 |
| Conservation Communication CIC | Professional & scientific | 2025 |
| Consilotech Ltd | Professional & scientific | 2023 |
| Continental Plant and Equipment Limited | Manufacturing | 1986 |
| Cooper Consultants Limited | Extraterritorial | 2024 |
| Cooper's Fish & Chips Limited | Hospitality | 2025 |
| Copeland Haven PCN Limited | Health & social care | 2025 |
| Corban Psychology Ltd | Health & social care | 2015 |
| Core Media Design Limited | Information & communication | 2008 |
| Cosmetic Skin Care Limited | Health & social care | 2012 |
| Cosmetic Skin Solutions Limited | Health & social care | 2018 |
| Courtyard Holidays Limited | Hospitality | 2025 |
| Cove Clinic Ltd. | Other services | 2025 |
| Covernant Ltd | Financial services | 2023 |
| Cowlin & Higgens Limited | Professional & scientific | 2016 |
| Cowperthwaites Garage Limited | Wholesale & retail | 2013 |
| COY Boutique Limited | Real estate | 2003 |
| Crafty Baker Limited | Wholesale & retail | 2016 |
| Cragside Spirit Company Ltd | Manufacturing | 2018 |
| Craig Brass Systems Limited | Information & communication | 2014 |
| Craig Mclean Flooring Limited | Construction | 2025 |
| Crancosta Limited | Real estate | 1976 |
| Creative Badger Films Limited | Information & communication | 2008 |
| Creative Capture Photography Ltd | Professional & scientific | 2024 |
| Creative Property Finance Ltd | Financial services | 2026 |
| Crepes&Bubblewaffles Limited | Wholesale & retail | 2020 |
| Crossfell Campers Ltd | Wholesale & retail | 2023 |
| Crossfit Cumbria Limited | Arts & recreation | 2012 |
| Crown Inn Morland Limited | Hospitality | 2026 |
| Cs&Md Ltd | Hospitality | 2026 |
| Ct&Jl Services Limited | Agriculture & fishing | 2013 |
| CTB Property Developments Ltd | Real estate | 2010 |
| Cultram Close Management Company Ltd | Real estate | 2024 |
| Cumberland County Motor Cycling Club Limited | Other services | 1982 |
| Cumberland Express Ltd | Other services | 2025 |
| Cumberland Taverns Limited | Real estate | 2002 |
| Cumbria and Lancashire Fire Safety Ltd | Professional & scientific | 2020 |
| Cumbria Association of Local Councils Limited | Other services | 2023 |
| Cumbria Canine Services Ltd | Arts & recreation | 2024 |
| Cumbria Card Collectors Ltd | Wholesale & retail | 2025 |
| Cumbria Catering and Events Ltd | Hospitality | 2023 |
| Cumbria Christian Learning | Education | 2002 |
| Cumbria Clean Ltd | Administrative & support | 2023 |
| Cumbria Cleaning Solutions Ltd | Administrative & support | 2025 |
| Cumbria Clock Company Limited | Other services | 2002 |
| Cumbria Clothing Collective CIC | Professional & scientific | 2024 |
| Cumbria Dental Care Limited | Health & social care | 2026 |
| Cumbria Family Support Ltd | Health & social care | 2001 |
| Cumbria Fire & Safety Training Limited | Public administration | 2020 |
| Cumbria Garden Buildings Limited | Extraterritorial | 2022 |
| Cumbria Granite Memorials Limited | Manufacturing | 2023 |
| Cumbria Heritage Ltd | Real estate | 2022 |
| Cumbria Mortgage Centre Limited | Financial services | 2018 |
| Cumbria Oxyhealthcare Limited | Wholesale & retail | 2024 |
| Cumbria Property Maintanence Ltd | Construction | 2021 |
| Cumbria Pubs Limited | Hospitality | 2021 |
| Cumbria Quality Care Limited | Health & social care | 2012 |
| Cumbria Quarrying Services Limited | Mining & quarrying | 2005 |
| Cumbria Renovations Ltd | Construction | 2024 |
| Cumbria Rural Ltd | Administrative & support | 2022 |
| Cumbria Steam & Vintage Vehicle Society Limited | Arts & recreation | 1974 |
| Cumbria X-Press Holdings Limited | Financial services | 2007 |
| Cumbria.Digital Ltd | Extraterritorial | 2022 |
| Cumbrian Discoveries Limited | Administrative & support | 1996 |
| Cumbrian Knee Clinic Limited | Administrative & support | 2009 |
| Cumbrian Local Publications Ltd | Information & communication | 2007 |
| Cumbrian Property Services Limited | Administrative & support | 2005 |
| Cumbrian Slate Memorials Ltd | Manufacturing | 2021 |
| Cumbrian Stone Limited | Mining & quarrying | 2006 |
| Curee Limited | Education | 2003 |
| Cuthbert and Stafford Hulme (Properties) Limited | Real estate | 2020 |
| CW Estates (Cumbria) Ltd | Agriculture & fishing | 2026 |
| CW Plant Services Limited | Manufacturing | 2017 |
| Cycleactive Limited | Administrative & support | 1996 |
| Cyclewise Training Limited | Arts & recreation | 2005 |
| Cytec Consulting UK Limited | Professional & scientific | 2022 |
| D & a Kidd (Cumbria) Limited | Wholesale & retail | 2024 |
| D & C Fawcett Ltd | Agriculture & fishing | 2006 |
| D & H Autocare Ltd | Wholesale & retail | 2013 |
| D & M Mcviety Limited | Other services | 2012 |
| D & M Porter Limited | Manufacturing | 1977 |
| D Broughton Limited | Wholesale & retail | 2015 |
| D Campbell Plumbing & Heating Limited | Construction | 2014 |
| D G and L M Strong Limited | Agriculture & fishing | 2014 |
| D G Shearing Limited | Agriculture & fishing | 2024 |
| D Graham Engineering Ltd | Professional & scientific | 2018 |
| D J Kirkton Consulting Limited | Professional & scientific | 2022 |
| D Kitching Agricultural Services Ltd | Agriculture & fishing | 2024 |
| D L Penhallurick Limited | Real estate | 2016 |
| D Mcmenamin Racing Limited | Arts & recreation | 2022 |
| D Tallentire Limited | Construction | 2002 |
| D W Toppin Limited | Wholesale & retail | 2008 |
| D Wilson Bricklaying Ltd | Construction | 2021 |
| D. S. Heritage Developments Limited | Manufacturing | 1999 |
| D3 Ltd | Construction | 2002 |
| Daco Ltd | Arts & recreation | 2021 |
| Dacre Investments Limited | Financial services | 2010 |