| Crown Creative Investments Limited | Hospitality | 2020 |
| Crown Fire Security Limited | Construction | 2013 |
| Crown Industries Limited | Construction | 2011 |
| Crown Jesus Ministries | Other services | 2001 |
| Crown Laboratories Global Ltd. | Wholesale & retail | 2003 |
| Crown Sports & Services Ltd | Wholesale & retail | 2025 |
| Crown Trade Solutions Limited | Wholesale & retail | 2025 |
| Crpgp Ltd | Real estate | 2023 |
| CRS and SON Ltd | Wholesale & retail | 2023 |
| CRS Property Precision Ltd | Households | 2025 |
| Crucible (NO.1) Ltd | Financial services | 2024 |
| Crucible (NO.2) Ltd | Financial services | 2024 |
| Cruinn Advisory Limited | Professional & scientific | 2020 |
| Cruinn Assets Limited | Administrative & support | 2024 |
| Cruise Genie UK Ltd | Professional & scientific | 2025 |
| Cruit Services Limited | Construction | 2016 |
| Crumb Club Belfast Ltd | Hospitality | 2026 |
| Crumexec Consulting Ltd | Information & communication | 2025 |
| Crumlin China Belfast Limited | Hospitality | 2026 |
| Crumlin Road Gaol Catering Limited | Hospitality | 2016 |
| Crumlin Road Gaol Ltd | Arts & recreation | 2012 |
| Crusaders in the Community C.I.C. | Education | 2021 |
| Crusca Pasta Limited | Manufacturing | 2026 |
| Cruthin Enterprises CIC | Construction | 2024 |
| Crux Holdings Limited | Financial services | 2021 |
| Cruz DE Nevado Limited | Wholesale & retail | 2020 |
| Crybaby Studios Ltd | Information & communication | 2022 |
| Crydel Limited | Education | 2003 |
| Cryonic UK and Ireland Limited | Wholesale & retail | 2019 |
| Cryotanks Group Limited | Financial services | 2025 |
| Cryotanks Limited | Construction | 2004 |
| Cryotech Engineering Technology Innovation Ltd | Professional & scientific | 2023 |
| Cryptech Cyber Consultancy Limited | Information & communication | 2026 |
| Crypto Service Capital LP | | 2018 |
| Crystal Healthcare Ltd | Health & social care | 2024 |
| Crystal House 2025 Ltd | Hospitality | 2026 |
| Crystal Nails & Spa Ltd | Other services | 2025 |
| Crystal Palace LIN Limited | Hospitality | 2025 |
| CS Autos N.I Ltd | Wholesale & retail | 2025 |
| CS Developments Limited | Construction | 2006 |
| CS Director Services Limited | Administrative & support | 2002 |
| CS Property Rentals Ltd | Real estate | 2024 |
| CSB Painting Ltd | Construction | 2020 |
| CSG Construction Ltd | Construction | 2018 |
| CSI Management Services Ltd | Professional & scientific | 2020 |
| CSI1818 Limited | Construction | 2018 |
| CSL Flooring Ltd | Construction | 2015 |
| Csli (Belfast) Ltd | Education | 2017 |
| CSM Property Management Ltd. | Real estate | 2019 |
| CSO Contracts Ltd | Construction | 2023 |
| CSP Assist Ltd | Households | 2015 |
| Cspq FMA Ltd | Wholesale & retail | 2024 |
| Csra Properties Limited | Real estate | 2010 |
| CSS Coffee Ltd | Hospitality | 2025 |
| CSS Motors Ltd | Wholesale & retail | 2023 |
| CST (N.I) Ltd | Transport & logistics | 2026 |
| Cstp Events Ltd | Professional & scientific | 2023 |
| CSV Employees Trustees Ltd | Extraterritorial | 2022 |
| CSW Electrical Installations Ltd | Construction | 2026 |
| CSW Engineering Ltd | Manufacturing | 2018 |
| CSX Ventures Limited | Financial services | 2025 |
| CT NI652359 Limited | Agriculture & fishing | 2018 |
| CTB Transport Logistics Ltd | Transport & logistics | 2015 |
| CTD Lighting Limited | Manufacturing | 2015 |
| CTN Belfast Ltd | Hospitality | 2020 |
| CTS Group N.I Limited | Financial services | 2026 |
| Cuan Catering Limited | Hospitality | 2018 |
| Cuan Construction Ltd | Construction | 2016 |
| Cuan Estates Limited | Construction | 2008 |
| Cuan Mews Management Ltd | Households | 2017 |
| CUB Holdings Limited | Financial services | 2021 |
| Cuban Sandwich Factory Ltd | Hospitality | 2023 |
| Cube (N.I.) Limited | Wholesale & retail | 2011 |
| Cubig Ltd | Information & communication | 2025 |
| Cubit Health Ltd | Health & social care | 2026 |
| Cubix Logistics Limited | Wholesale & retail | 2026 |
| Cuchulainn Holdings Limited | Financial services | 2021 |
| Cuckoo Sun Limited | Wholesale & retail | 2023 |
| Cuddl Ltd | Wholesale & retail | 2020 |
| Cuddles Childminding Ltd | Health & social care | 2021 |
| Cuizhen Ltd | Wholesale & retail | 2025 |
| Culan Close Property Management Limited | Construction | 2024 |
| Culann Productions Ltd | Manufacturing | 2026 |
| Culcavey Management Limited | Households | 1990 |
| Culcrum Ltd | Real estate | 2025 |
| Cullen Transport & Trailer Services Ltd | Wholesale & retail | 2008 |
| Cullies Ltd | Real estate | 2020 |
| Cullintraw Limited | Information & communication | 2016 |
| Cully Contracts (N.I.) Limited | Construction | 2018 |
| Cully Contracts Co Ltd | Construction | 2011 |
| Cully Property Limited | Households | 2026 |
| Cullyrammer Wind Ltd | Energy | 2017 |
| Culmore Property Investments Limited | Real estate | 2021 |
| Culrath Ltd | Information & communication | 2019 |
| Cultra Estates Limited | Real estate | 2015 |
| Cultra Station Ltd | Households | 2017 |
| Cultura Lifestyle Limited | Hospitality | 2022 |
| Culture Factory Ltd | Information & communication | 2026 |
| Cumann Culturtha Mhic Reachtain | Arts & recreation | 2002 |
| Cumhran UK & Ireland Limited | Wholesale & retail | 2024 |