| Capital Gearing Trust P.L.C. | Financial services | 1963 |
| Capital Gold LP | | 2016 |
| Capital Hygiene Supplies Ltd | Wholesale & retail | 2007 |
| Capitate Ltd | Health & social care | 2024 |
| Caple Ireland Ltd | Extraterritorial | 2025 |
| Capparelli Limited | Hospitality | 2021 |
| Capstone Estate Management Limited | Extraterritorial | 2024 |
| Capstone Trust Limited-The | Real estate | 1982 |
| Captain Cargo Ltd | Transport & logistics | 2010 |
| Captain Courier Limited | Transport & logistics | 1992 |
| Captaincooks 2013 Ltd | Hospitality | 2013 |
| Captains Table Belfast Limited | Hospitality | 2017 |
| Captiva Limited | Information & communication | 2026 |
| Captrex Credit L.P. | | 2017 |
| Capture Rock Services Ltd | Construction | 2020 |
| Captured Carbon (N.I.) Limited | Energy | 2017 |
| Capzy Ltd | Information & communication | 2026 |
| Car + Color Ltd. | Wholesale & retail | 2006 |
| Car College Limited | Education | 2020 |
| Car Search NI Ltd | Other services | 2019 |
| Car Smart N.I. (2026) Ltd | Professional & scientific | 2026 |
| Cara Group Travel UK Ltd | Administrative & support | 2026 |
| Cara Mcilroy Ltd | Health & social care | 2025 |
| Cara Network Solutions Limited | Information & communication | 2013 |
| Cara-Friend | Other services | 2013 |
| Caragh Shopfitting Ltd | Construction | 2023 |
| Caranah Consulting Limited | Information & communication | 2019 |
| Caravel Property (NO.2) Limited | Real estate | 2025 |
| Carbane Associates Ltd | Professional & scientific | 2020 |
| Carberry & Co Group Ltd | Financial services | 2024 |
| Carberry Catering Limited | Hospitality | 2014 |
| Carbon Balance Network Limited | Professional & scientific | 2022 |
| Carbon Cleaning NI Ltd | Wholesale & retail | 2017 |
| Carbon Technologies Group Ltd | Water & waste | 2021 |
| Carbonfit Ltd | Professional & scientific | 2021 |
| Carbtuneshop Ltd | Manufacturing | 2026 |
| Carcon Properties Limited | Real estate | 1969 |
| Card Terminal Payment Systems Limited | Financial services | 2019 |
| Cardea Property Ltd | Real estate | 2021 |
| Cardiac Physiologist Ltd | Health & social care | 2024 |
| Cardinal Analytics International Ltd | Information & communication | 2018 |
| Cardinal Analytics Ltd | Information & communication | 2013 |
| Cardiopak Manufacturer Ltd | Manufacturing | 2025 |
| Care (Ireland) Ltd | Professional & scientific | 2013 |
| Care Crew (Belfast) Limited | Administrative & support | 2025 |
| Care Dots Limited | Information & communication | 2025 |
| Care Pathways Health Group Limited | Health & social care | 2026 |
| Carecall (NI) Limited | Health & social care | 2000 |
| Career Reboot Ltd | Administrative & support | 2019 |
| Careers N Kids | Education | 1991 |
| Carelli Enterprises Ltd | Hospitality | 2019 |
| Carenna Developments Limited | Construction | 2023 |
| Carenna Investments Limited | Construction | 2026 |
| Caretrack-Ai Limited | Information & communication | 2025 |
| Carey Management Consultancy Limited | Professional & scientific | 2013 |
| Carey Patrick Ltd | Real estate | 2018 |
| Cargan Development Management Company Limited | Real estate | 2024 |
| Cargo Air Freight Limited | Transport & logistics | 1967 |
| Cargo Forwarding Limited | Transport & logistics | 1990 |
| Cargo Solutions (N.I.) Limited | Administrative & support | 2023 |
| Caring Angels Homecare (NI) Ltd | Health & social care | 2025 |
| Caring Breaks Limited | Health & social care | 2000 |
| Caring Home 2 Home Ltd | Health & social care | 2022 |
| Caring Ministries | Other services | 2013 |
| Caring Without Borders CIC | Other services | 2022 |
| Carl Quinn DOP Limited | Information & communication | 2021 |
| Carla Stronge Casting Ltd | Professional & scientific | 2013 |
| Carlane Construction Ltd | Construction | 2015 |
| Carlane Limited | Hospitality | 2012 |
| Carleton Financial Planning Limited | Professional & scientific | 1968 |
| Carley Jones Ltd | Wholesale & retail | 2025 |
| Carlile Financial Services Ltd | Financial services | 2014 |
| Carlin Haircare Ltd | Other services | 2011 |
| Carlin Planning Limited | Professional & scientific | 2019 |
| Carlin Properties Limited | Real estate | 2022 |
| Carlin Solicitors Ltd. | Professional & scientific | 2017 |
| Carlisle Inns Ltd | Hospitality | 2017 |
| Carloverni Limited | Information & communication | 2018 |
| Carlow 2010 Limited | Professional & scientific | 2010 |
| Carlow Trading Limited | Professional & scientific | 2006 |
| Carma Holdings Ltd | Wholesale & retail | 2020 |
| Carma Manufacturing Ltd | Wholesale & retail | 2020 |
| Carma Retail Ltd | Wholesale & retail | 2020 |
| Carmercial Ltd | Administrative & support | 2026 |
| Carmoney Energy Limited | Energy | 2013 |
| Carn Developments Ltd | Construction | 2009 |
| Carn Hill Windfarm Limited | Energy | 2010 |
| Carna Holdings Limited | Transport & logistics | 2015 |
| Carnally Enterprises Ltd | Education | 2026 |
| Carnanee Competition Livery Limited | Agriculture & fishing | 2014 |
| Carnany Limited | Wholesale & retail | 2005 |
| Carnbrae Limited | Real estate | 2018 |
| Carnegie Oldpark Library Association Ltd | Professional & scientific | 2025 |
| Carnegie Oldpark Limited | Arts & recreation | 2016 |
| Carnesure Mews Management Company Limited | Real estate | 2016 |
| Carnextdoor EU Ltd | Extraterritorial | 2022 |
| Carney Hall Management Company Limited | Extraterritorial | 2001 |
| Carney Hill Developments Ltd | Construction | 2022 |
| Carnlea Wood Management Company Limited | Households | 2021 |
| Carnreagh Properties Ltd | Real estate | 2003 |