| Corner Space Ltd | Hospitality | 2025 |
| Cornerstone Church | Other services | 2015 |
| Cornerstone Design and Contracts Ltd | Construction | 2023 |
| Cornerstone Technologies Ltd | Professional & scientific | 2020 |
| Cornonagh Management Limited | Construction | 2016 |
| Corpstone L.P. | | 2015 |
| Corrbrand Limited | Arts & recreation | 2024 |
| Corrigan Gallagher Contracts (NI) Limited | Manufacturing | 2023 |
| Corry Investments Limited | Real estate | 2022 |
| Cosmetic Services Limited | Other services | 2023 |
| Cosmeticshq Limited | Other services | 2015 |
| Costume Corner Limited - the | Wholesale & retail | 2005 |
| Cosy Bar Ltd | Hospitality | 2020 |
| Coulter Fisher Haulage Ltd | Transport & logistics | 2022 |
| Coulter Industries Limited | Construction | 1998 |
| Country Carpets & Furniture Store Limited | Wholesale & retail | 2002 |
| Country Gold LP | | 2016 |
| Country Guest House Limited | Hospitality | 2003 |
| Courmac Properties Ltd | Real estate | 2017 |
| Courmac Trading Ltd | Hospitality | 2017 |
| Courtney PA Consulting Ltd | Administrative & support | 2015 |
| Couture Grandeur Limited | Wholesale & retail | 2016 |
| Couture Shoes Limited | Wholesale & retail | 2017 |
| Cove Environmental Consulting Limited | Professional & scientific | 2018 |
| CP & a Supplies Ltd | Wholesale & retail | 2012 |
| CP Bricklaying Ltd | Construction | 2014 |
| CP Contract Services Limited | Construction | 2008 |
| CP Pharma Solutions Ltd | Wholesale & retail | 2019 |
| CPC Capital Group Limited | Manufacturing | 2026 |
| Cplb Ltd | Other services | 2025 |
| Cplm Limited | Real estate | 2004 |
| CPM (Central Park Mallusk) Limited | Financial services | 2019 |
| CPS Ireland Ltd | Administrative & support | 2021 |
| CQ Bricklaying Ltd | Construction | 2026 |
| CQ Electrics Ltd | Construction | 2024 |
| CQD Ltd | Wholesale & retail | 2025 |
| CR Plant Services Limited | Administrative & support | 2015 |
| Craft Coffee Ireland Ltd | Hospitality | 2026 |
| Craftech Ltd | Manufacturing | 2024 |
| Crafty Crumbs Cottage Ltd | Hospitality | 2026 |
| Craigmore A.B.C CIC | Education | 2023 |
| Craigmore Tyres Ltd | Wholesale & retail | 2021 |
| Craigmount Property Ltd | Extraterritorial | 2003 |
| Crana Stone Ltd | Manufacturing | 2019 |
| Crancorran Groundworks and Civils Ltd | Construction | 2025 |
| Cranfield Caravan Park Limited | Hospitality | 2018 |
| Cranfield Meadows Management Company Limited | Real estate | 2009 |
| Cranmore Excellence in Dentistry Limited | Health & social care | 2012 |
| Cranmore Limited | Professional & scientific | 2003 |
| Cranney Mccabe Limited | Professional & scientific | 2016 |
| Crannog Contracts Ltd | Construction | 2014 |
| Cranny Property Ltd | Real estate | 2024 |
| Crash Services Ltd | Other services | 2004 |
| Craving Insights Limited | Professional & scientific | 2026 |
| Crawford Leather Company Limited | Financial services | 2018 |
| Crawford Leather Group Limited | Financial services | 2021 |
| Crawfords Glen Management Company Limited | Households | 2002 |
| CRC Tactical Ltd | Wholesale & retail | 2019 |
| Creamery Foods Ltd | Hospitality | 2013 |
| Creative Design Events Limited | Other services | 2012 |
| Credologic L.P. | | 2017 |
| Credoport Engineering L.P. | | 2015 |
| Cregagh Developments Ltd | Construction | 2018 |
| Creggan Maintenance Ltd | Administrative & support | 2026 |
| Creggan Men's Shed Limited | Health & social care | 2025 |
| Creggan Transport (Ireland) Limited | Transport & logistics | 1994 |
| Creggan Van Hire Ltd | Administrative & support | 2020 |
| Cregganbane Properties Limited | Households | 2025 |
| Cregganduff Financial Ltd | Financial services | 2020 |
| Crego Limited | Wholesale & retail | 2025 |
| Creid Services Ltd | Construction | 2017 |
| Creid Surfaces Ltd | Construction | 2018 |
| Cremorials (N.I.) Ltd | Construction | 2020 |
| Crestrox Industries L.P. | | 2017 |
| Crieve Construction Ltd | Construction | 2016 |
| Crieve Investments Limited | Construction | 2015 |
| Crilly Transport Ltd | Transport & logistics | 2004 |
| Crisis Cafe CIC | Health & social care | 2020 |
| CRL Investments Ltd | Financial services | 2022 |
| Croft Road Management Limited | Households | 2004 |
| Crofthill Management Limited | Real estate | 2008 |
| Cromlech 1951 Limited | Extraterritorial | 2013 |
| Cross Creations Ltd | Wholesale & retail | 2019 |
| Cross Investments (IRL) Ltd | Real estate | 2020 |
| Cross Management Limited | Real estate | 2006 |
| Cross Mountain Ltd | Real estate | 2021 |
| Cross Square Property Ltd | Real estate | 2017 |
| Cross Trading Solutions Ltd | Financial services | 2024 |
| Cross Trans Limited | Transport & logistics | 2017 |
| Crossan Formwork Ltd | Construction | 2024 |
| Crossan Groundwork Contracts Ltd | Construction | 2025 |
| Crossan Motorcycles Limited | Wholesale & retail | 2004 |
| Crossan Motorcycles Trading Ltd | Wholesale & retail | 2020 |
| Crossey-Truesdale Retail Group Ltd | Wholesale & retail | 2017 |
| Crossflex Logistics L.P. | | 2017 |
| Crosshill Group Ltd | Construction | 2023 |
| Crossmaglen 2025 Limited | Hospitality | 2025 |
| Crossmaglen and District Development Company Limited | Professional & scientific | 1992 |
| Crossmaglen Community Association Limited - the | Health & social care | 1986 |
| Crossmaglen Community Sports Development Company Ltd | Arts & recreation | 2013 |