| C&L Professional Services Limited | Information & communication | 2012 |
| C&M Trotter Limited | Water & waste | 1995 |
| CAD Medical Ltd | Wholesale & retail | 2023 |
| Cafe Dawn-Marie Ltd | Hospitality | 2022 |
| Cafe Deluxe 68 Limited | Hospitality | 2026 |
| Cairn Lodge Services Limited | Extraterritorial | 2014 |
| Cal's Coffee Limited | Hospitality | 2015 |
| Calma Goalkeeping Ltd | Manufacturing | 2018 |
| Calthwaite Hall Leisure Ltd | Hospitality | 2024 |
| Calvert Way (Keswick) Property Management Limited | Real estate | 2015 |
| Calvin Awde Ltd | Construction | 2004 |
| CAM Engineers Limited | Professional & scientific | 2025 |
| Campbell-Bell Communications Limited | Professional & scientific | 2007 |
| Canny Properties Ltd | Real estate | 2022 |
| Canterbury Functional Communications Ltd | Health & social care | 2016 |
| Capriccio 46 Limited | Hospitality | 2012 |
| Capriccio Express Limited | Extraterritorial | 2012 |
| Carbotech-Europe Limited | Manufacturing | 2000 |
| Cardiff Maths Tutor Limited | Education | 2025 |
| Carer Support Eden Ltd | Health & social care | 2003 |
| Carleton Electrical (Penrith) Limited | Construction | 2014 |
| Carlisle Damp Proofing Ltd | Construction | 2023 |
| Carlisle Diocesan Board of Finance Limited | Other services | 1893 |
| Carlisle Physiotherapy Limited | Health & social care | 2002 |
| Carn Olva Investments Limited | Financial services | 2026 |
| Carp Properties Ltd | Real estate | 2025 |
| Carrock Fell Farming Ltd | Agriculture & fishing | 2025 |
| Carrock Homes Limited | Construction | 2016 |
| Carrock House (Penrith) Management Company Limited | Households | 2018 |
| Carrock Ltd | Construction | 2026 |
| Castle Court (Property Management) Penrith Limited | Real estate | 2007 |
| Castle Foundry Management Limited | Households | 2011 |
| Castle Garage Penrith Limited | Wholesale & retail | 2016 |
| Castlegate Development Limited | Agriculture & fishing | 2019 |
| Castleview Construction (Cumbria) Limited | Construction | 2016 |
| Cat Continental Ltd | Transport & logistics | 2025 |
| Catchment Designs Limited | Construction | 2019 |
| Catherine Edwards Consulting Ltd | Professional & scientific | 2025 |
| Catsource Ltd | Information & communication | 2013 |
| Catstycam Limited | Wholesale & retail | 2002 |
| Cawdale Contracting Ltd | Construction | 2026 |
| Cemmick & Wylder Limited | Arts & recreation | 2008 |
| Centurion Park Management Company Limited | Other services | 2010 |
| Cert (UK) Ltd. | Hospitality | 2016 |
| Chambers Garage Limited | Wholesale & retail | 2002 |
| Chandlers Country Estates Ltd | Extraterritorial | 2015 |
| Chandlers Country Fayre Limited | Hospitality | 2002 |
| Chandlers Country Properties Limited | Energy | 2002 |
| Chandlers Homes Limited | Construction | 2015 |
| Change Plus Limited | Professional & scientific | 2019 |
| Chapel Beck Limited | Financial services | 2018 |
| Chapman Gold Ltd | Wholesale & retail | 2026 |
| Charmwyck Ltd. | Administrative & support | 2012 |
| Charterhouse Developments Limited | Real estate | 2000 |
| Chase Geoscience Limited | Professional & scientific | 2013 |
| Cherry Tree Gifts Ltd | Wholesale & retail | 2008 |
| Chestnut Properties (Penrith) Limited | Households | 1988 |
| CHG Consulting Limited | Professional & scientific | 2020 |
| Chplasticsurgery Ltd | Health & social care | 2025 |
| Chris Dent | Agriculture & fishing | 2008 |
| Chris Edmondson Cleaning Limited | Administrative & support | 2014 |
| Chris Parker Building and Joinery Contractors Limited | Construction | 2004 |
| Christian Dodd LLP | | 2008 |
| Christopher Kilmurry Partnership Ltd | Professional & scientific | 2018 |
| Churches Trust for Cumbria | Other services | 2008 |
| Châtellier Robinson Ltd | Information & communication | 2019 |
| Ciel Hotels Limited | Hospitality | 2007 |
| Cinequatix Ltd | Information & communication | 2023 |
| Citizens Advice, Cumbria | Health & social care | 1999 |
| City Village Limited | Real estate | 1998 |
| Civic Ventures Limited | Information & communication | 2017 |
| CJS Property Services Ltd | Real estate | 2025 |
| Clare Webster Properties Limited | Construction | 2017 |
| Clark Enterprise Ltd | Real estate | 2025 |
| Classic Desserts Limited | Manufacturing | 1998 |
| Clavering Limited | Real estate | 2014 |
| CLC Recycling Services Limited | Water & waste | 2023 |
| Clear Direction Consultancy Services Limited | Professional & scientific | 2021 |
| Cleasby Developments Limited | Hospitality | 2025 |
| Clenton Developments Ltd | Real estate | 2024 |
| Clifton Jerseys | Administrative & support | 2007 |
| Climb Youth Therapy Limited | Health & social care | 2026 |
| Clive Seal & Sons Limited | Households | 2017 |
| Cloudyfells Investments Ltd | Financial services | 2024 |
| CMT Business Psychologists Limited | Professional & scientific | 2019 |
| Coaching Supervision Partnership Limited Liability Partnership | | 2021 |
| Cobalt Consultancy Services Ltd | Professional & scientific | 2012 |
| Cockermouth Projects Limited | Administrative & support | 2016 |
| Code Communications & Marketing Limited | Information & communication | 2010 |
| Coledale Estates (Whitehaven) Limited | Construction | 2024 |
| Coledale Estates Limited | Extraterritorial | 2022 |
| Coledale Property Holdings Limited | Financial services | 2022 |
| Coleman Roofing Ltd | Construction | 2022 |
| Colin Dawson Limited | Wholesale & retail | 2001 |
| Colinhillswims Ltd | Education | 2018 |
| Collins & Westmoreland Limited | Real estate | 2021 |
| Collmedia Limited | Professional & scientific | 2014 |
| Commendium Limited | Construction | 2000 |
| Complex Metal Facades Ltd | Professional & scientific | 2016 |
| Compton House Services Limited | Administrative & support | 1997 |