| Cathow Farm Holidays Limited | Hospitality | 2023 |
| CC Catering Cumbria Ltd | Hospitality | 2025 |
| CDF Property Investment Cumbria Ltd | Real estate | 2025 |
| CE Bar Thirty Two Ltd | Hospitality | 2023 |
| Central Garage Hand Car Wash Ltd | Other services | 2018 |
| Cheatcb Ltd | Administrative & support | 2019 |
| Chime Onyewuchi Ltd | Hospitality | 2023 |
| Chimney Sheep Limited | Manufacturing | 2012 |
| Christian Civil Engineering and Surveying Limited | Professional & scientific | 2015 |
| Christy Place Ltd | Real estate | 2022 |
| Chude Properties Ltd | Real estate | 2022 |
| Citizens Advice Allerdale | Information & communication | 2003 |
| CJF Bathrooms Limited | Construction | 2024 |
| CJH Ground Works & Construction Ltd | Construction | 2020 |
| Clarkin Electronics Limited | Manufacturing | 2002 |
| Clarkson Developments (Holdings) Ltd | Financial services | 2023 |
| Clarkson Fast Foods Ltd | Hospitality | 2025 |
| Clear and Credible Ltd | Professional & scientific | 2020 |
| CM Marine Engineering Limited | Professional & scientific | 2025 |
| CMQ Health & Wellness Limited | Other services | 2024 |
| CMS Developments (Cumbria) Limited | Health & social care | 2017 |
| Cmso Ltd | Health & social care | 2024 |
| Cockermouth Interiors Ltd | Other services | 2010 |
| Colour GRO Limited | Agriculture & fishing | 2001 |
| Combined Property Services Ltd | Construction | 2025 |
| Competitions Anonymous Limited | Other services | 2026 |
| Coms Defence Limited | Professional & scientific | 2024 |
| Coms Energy Limited | Professional & scientific | 2024 |
| Connor Mason Accommodation Ltd | Real estate | 2025 |
| Connor Mason Capital Ltd | Administrative & support | 2025 |
| Connor Mason Sourcing Ltd | Administrative & support | 2024 |
| Cookie Racing Limited | Arts & recreation | 2015 |
| Coombe & Sharpe Landscaping Limited | Administrative & support | 2007 |
| Coowan Group Limited | Health & social care | 2025 |
| Coral Q Holdings Ltd | Real estate | 2026 |
| Core Nuclear Group Ltd | Professional & scientific | 2021 |
| Core Nuclear Properties Limited | Households | 2025 |
| Core Nuclear Solutions Ltd | Manufacturing | 2010 |
| Corker Wallace Resourcing Limited | Administrative & support | 2010 |
| Cotswold Sleep Clinic Ltd | Health & social care | 2023 |
| Countrywide Tiles Limited | Wholesale & retail | 2001 |
| Cozura CIC | Other services | 2024 |
| CPN Global Ltd | Real estate | 2025 |
| Craig Steele Double Glazing Ltd | Construction | 2018 |
| Create Happiness CIC | Health & social care | 2020 |
| Creativity Matters Ltd | Professional & scientific | 2021 |
| CRL Logistics Ltd | Transport & logistics | 2018 |
| CRL MED Ltd | Health & social care | 2022 |
| Crone’S Motors Ltd | Wholesale & retail | 2021 |
| Crooked River Brewing Co Ltd | Manufacturing | 2023 |
| CSS Property Development Ltd | Real estate | 2025 |
| Cubed Clever Ltd | Transport & logistics | 2025 |
| Cumberland Flower Farm Ltd | Agriculture & fishing | 2024 |
| Cumberland Marine Services Ltd | Administrative & support | 2018 |
| Cumberland Stove Services Ltd | Manufacturing | 2016 |
| Cumberland Strongman Academy Ltd | Arts & recreation | 2024 |
| Cumberland Wagyu Limited | Agriculture & fishing | 2022 |
| Cumbria Access and Engineering Limited | Professional & scientific | 2024 |
| Cumbria Anaesthetics Services Ltd | Health & social care | 2022 |
| Cumbria Aqua Blast & Cerakote Limited | Wholesale & retail | 2026 |
| Cumbria ATA Limited | Administrative & support | 2006 |
| Cumbria Bars Limited | Hospitality | 2022 |
| Cumbria Bright Ltd | Other services | 2024 |
| Cumbria Engineering Solutions Limited | Professional & scientific | 2022 |
| Cumbria Forklifts Ltd | Manufacturing | 2016 |
| Cumbria Heating Solutions Limited | Wholesale & retail | 2021 |
| Cumbria Medical Services Limited | Health & social care | 2013 |
| Cumbria O & M Services Limited | Professional & scientific | 2014 |
| Cumbria Property Investments Ltd | Households | 2024 |
| Cumbria Recycling Limited | Wholesale & retail | 2005 |
| Cumbria Rugby Union Referees Limited | Arts & recreation | 2018 |
| Cumbria Safety Management Services Limited | Professional & scientific | 2023 |
| Cumbria Spicy Restaurant Ltd | Hospitality | 2026 |
| Cumbria Superglaze Limited | Construction | 2007 |
| Cumbria Surgical Services Limited | Health & social care | 2022 |
| Cumbria Valeting Ltd | Administrative & support | 2024 |
| Cumbria Youth Alliance | Education | 1999 |
| Cumbrian Shellfish Limited | Administrative & support | 2017 |
| Curious Collaborations Limited | Professional & scientific | 2021 |
| Currian Limited | Information & communication | 2014 |
| CV International Consultancy Ltd | Administrative & support | 2021 |
| CWP Investment Properties Ltd | Real estate | 2025 |
| Cyclife UK Ltd | Water & waste | 2003 |
| D & L Engineering Services Limited | Professional & scientific | 2008 |
| D Walker (Agri) Ltd | Agriculture & fishing | 2018 |
| D Y Food Limited | Hospitality | 2017 |
| D. Richardson Electrical Services Limited | Construction | 1996 |
| D.K. Instruments Limited | Professional & scientific | 2003 |
| D.White Building Contractor Ltd | Construction | 2013 |
| DAB Technical Services Limited | Professional & scientific | 2015 |
| Daily Crave 92 Ltd | Hospitality | 2022 |
| Damara Psychotherapy and Counselling Services Limited | Health & social care | 2018 |
| Dargavel Engineering Limited | Construction | 1995 |
| Dargavel Estates Limited | Real estate | 2023 |
| Darren Block Roofing Ltd | Construction | 2026 |
| Dave Brown Limited | Transport & logistics | 2020 |
| David J Fisher Limited | Construction | 2002 |
| David Robinson Limited | Construction | 2003 |
| Davidson Delivery & Collection Services Limited | Transport & logistics | 2002 |
| DC 45 Limited | Hospitality | 2019 |