| Cafe New Haven Limited | Wholesale & retail | 2015 |
| Cairnleigh Ltd | Agriculture & fishing | 2007 |
| Cairns Contracts Ltd | Construction | 2025 |
| Cairns Services Ltd | Wholesale & retail | 2023 |
| Cairo's Coffee Limited | Hospitality | 2026 |
| Calf and KIN Limited | Hospitality | 2022 |
| Cama Electrical Engineering Services Ltd | Professional & scientific | 2025 |
| Cambrian Developments Holdings Limited | Financial services | 2021 |
| Cambridge Global Resources Ltd | Professional & scientific | 2024 |
| Camcal NI Limited | Financial services | 2026 |
| Campbell & Haughey Solicitors Limited | Professional & scientific | 2010 |
| Campbell Portfolio Solutions Ltd | Real estate | 2025 |
| Campbell Power Services Ltd | Construction | 2025 |
| Campbell/O'Reilly Property Solutions Limited | Real estate | 2021 |
| Candy Vault Ltd | Health & social care | 2025 |
| Cannard Holdings Ltd | Real estate | 2025 |
| Capatana Properties Limited | Construction | 2024 |
| Capital H Investments Ltd | Real estate | 2022 |
| Capt Cider Ltd | Wholesale & retail | 2024 |
| Captain Cooks Cafe Ltd | Hospitality | 2025 |
| Capture Athletics Ltd | Wholesale & retail | 2022 |
| Cara Project Management Consulting Limited | Professional & scientific | 2014 |
| Care Byte Ltd | Wholesale & retail | 2026 |
| Carercore Ltd | Health & social care | 2026 |
| Cargans Outdoor Living Ltd | Wholesale & retail | 2024 |
| Carlen Construction Limited | Construction | 2023 |
| Carleton Estate Agents Ltd | Real estate | 2020 |
| Carleton Property Ltd | Real estate | 2022 |
| Carn Coldstore Limited | Transport & logistics | 2017 |
| Carn Customs Clearance Company Limited | Transport & logistics | 2018 |
| Carnival Thrill Ltd | Arts & recreation | 2025 |
| Carnland Limited | Agriculture & fishing | 2017 |
| Carpet Tile Solutions Limited | Wholesale & retail | 2004 |
| Carrick Meadows Management Company Limited | Households | 2016 |
| Cassidy Fuels Limited | Wholesale & retail | 2013 |
| Castle Vending | Extraterritorial | 2013 |
| Castlelane Offsales Limited | Wholesale & retail | 2014 |
| Catherine Falls Ltd | Professional & scientific | 2019 |
| CB1 Property Ltd | Real estate | 2020 |
| Cckm Limited | Real estate | 2019 |
| Cedar Hill Management Company (NI) Limited | Households | 2007 |
| Cell Block Grill Ltd | Hospitality | 2024 |
| Celshan Ltd | Financial services | 2022 |
| Celsio Services Ltd | Professional & scientific | 2024 |
| Celtic Airs Limited | Extraterritorial | 2004 |
| Centra Magheralin Ltd | Wholesale & retail | 2016 |
| Central Chemical Supplies Limited | Manufacturing | 1997 |
| Centre for Town Renewal CIC | Professional & scientific | 2026 |
| Centrepoint Leisure Limited | Real estate | 1989 |
| Cfhc Ltd | Health & social care | 2026 |
| Cfjona Ltd | Arts & recreation | 2025 |
| CFR 79 Limited | Manufacturing | 2009 |
| CH Global Finance Solutions Ltd | Professional & scientific | 2023 |
| Chacha's Local Ltd | Wholesale & retail | 2025 |
| Chala Chai Ltd | Manufacturing | 2020 |
| Changing Lives MH Northern Ireland Ltd | Health & social care | 2026 |
| Chapman Foods of Battlehill Ltd | Manufacturing | 2015 |
| Chapter by Chapter Limited | Information & communication | 2024 |
| Charles Lavery & Sons Ltd | Construction | 1997 |
| Chatsworth Carpets (Portadown) Limited | Wholesale & retail | 2004 |
| Chatsworth Carpets and Flooring Ltd | Construction | 2021 |
| Checkbox Entertainment Ltd | Information & communication | 2019 |
| Cheesy Grin Productions Ltd | Information & communication | 2022 |
| Cherry Plastics Ltd | Manufacturing | 2011 |
| Cherry Recycling Ltd | Water & waste | 2022 |
| Cherryhill Medical Ltd | Health & social care | 2020 |
| Cherrymount DC Ltd | Health & social care | 2026 |
| Cherrymount Healthcare Limited | Wholesale & retail | 1992 |
| Cherrymount Trading Limited | Other services | 2015 |
| Cherryvale Group Ltd | Manufacturing | 2018 |
| Chestnut Construction Limited | Construction | 2017 |
| Chestnut Hospitality Ltd | Hospitality | 2025 |
| Chewitts Ltd | Wholesale & retail | 2018 |
| Chiko's Ltd | Hospitality | 2016 |
| China Top Chef Aghalee Ltd | Hospitality | 2026 |
| China's Finest Lurgan Ltd | Hospitality | 2024 |
| Chinese Gourmet Moira Ltd | Hospitality | 2026 |
| Chipped&Sliced Ltd | Hospitality | 2025 |
| Choice Media Ltd | Information & communication | 2023 |
| Chris Auld Properties Ltd | Real estate | 2025 |
| Chris Auld Tree Services Ltd | Administrative & support | 2026 |
| Christ the Redeemer International Ministries - Portadown Limited | Other services | 2020 |
| Christopher Hughes Transport Limited | Transport & logistics | 2012 |
| Chukar Ltd | Wholesale & retail | 2024 |
| Chuong's Chinese Take Away Ltd | Hospitality | 2015 |
| Church Education Trust | Education | 2012 |
| Church Hill Derryhubbert Limited | Agriculture & fishing | 2022 |
| Church Road 2020 Ltd | Construction | 2019 |
| Church Street Pantry Ltd | Wholesale & retail | 2020 |
| Churchill Park Food Market Limited | Extraterritorial | 2001 |
| Ciaran Mulholland Construction Ltd | Construction | 2016 |
| Ciggy Vapes Armagh (NI) Ltd | Wholesale & retail | 2017 |
| Ciggy Vapes Ballynahinch (NI) Ltd | Wholesale & retail | 2017 |
| Ciggy Vapes Downpatrick (NI) Ltd | Wholesale & retail | 2017 |
| Ciggy Vapes Dunmurry (NI) Ltd | Wholesale & retail | 2019 |
| Ciggy Vapes East Belfast (NI) Ltd | Wholesale & retail | 2019 |
| Ciggy Vapes Lisburn (NI) Ltd | Wholesale & retail | 2021 |
| Cirrus Limited | Manufacturing | 1987 |
| Citea Ventures Limited | Wholesale & retail | 2024 |
| City Primary Ltd | Information & communication | 2023 |