| Center for Therapeutic and Rehabilitation Medicine Ltd. | Health & social care | 2014 |
| Center Services Ltd | Wholesale & retail | 2024 |
| Centermax L.P. | | 2015 |
| Central Filling Station Limited | Wholesale & retail | 1999 |
| Central Florists Ltd | Wholesale & retail | 2005 |
| Central Music Newry | Arts & recreation | 2013 |
| Central Neuro Services Limited | Health & social care | 2018 |
| Centre Spot Rentals Ltd | Arts & recreation | 2013 |
| Centre Ventures Limited | Wholesale & retail | 2018 |
| Centred Soul-Health & Wellbeing for ALL the Family C.I.C. | Health & social care | 2017 |
| CES20 Ltd | Professional & scientific | 2020 |
| CFG Developments Ltd | Real estate | 2023 |
| CFL Fuels Ltd | Wholesale & retail | 2013 |
| CFR 84 Limited | Professional & scientific | 2007 |
| CFS Property Limited | Construction | 2022 |
| CFT Limited | Wholesale & retail | 2018 |
| CG Joinery (IRE) Limited | Construction | 2018 |
| CGM Autos Ltd | Wholesale & retail | 2020 |
| CGS Travel Limited | Administrative & support | 2024 |
| CH Electrics Ltd | Construction | 2017 |
| Chambers Mcbride Holdings Ltd | Financial services | 2026 |
| Chancellor Utilities Ltd | Construction | 2024 |
| Chancellors Hall Management Limited | Households | 2007 |
| Chancellors Road Contracts Ltd | Extraterritorial | 2022 |
| Change Your Luck Ltd | Arts & recreation | 2024 |
| Changing Cycles Community Interest Company | Health & social care | 2020 |
| Chapel Hill and Beech Wood Management Company Ltd | Households | 2018 |
| Chapel View (Ardglass) Limited | Households | 2016 |
| Charlemont Properties Limited | Real estate | 2018 |
| Charles Cousins Ltd | Agriculture & fishing | 2009 |
| Charles Digney & Sons Limited | Other services | 2015 |
| Charlotte Street Court Limited | Households | 1998 |
| Charmel Fishing Ltd | Agriculture & fishing | 2025 |
| Chartley Services L.P. | | 2015 |
| Chartway Management L.P. | | 2017 |
| Chatverse Ltd | Information & communication | 2025 |
| Cheeky Monkeys Activity Centre Ltd | Hospitality | 2022 |
| Cheeky Monkeys Laser Ltd | Arts & recreation | 2016 |
| Cheflink International Limited | Wholesale & retail | 2019 |
| Cherry Cottage Nurseries and Garden Centre Ltd | Wholesale & retail | 2013 |
| Cherry Laurel Investments Limited | Financial services | 2022 |
| Cherrymount Management Company Limited | Households | 2012 |
| Chestnut Grange Management Company Limited | Households | 2014 |
| Chestnutt Holiday Parks Limited | Hospitality | 2018 |
| CHI Azuike Limited | Health & social care | 2025 |
| Chilli Dungannon Limited | Hospitality | 2021 |
| Chilli Food Group (NI) Limited | Financial services | 2021 |
| Chlorine Developments Ltd | Construction | 2021 |
| Chris Caulfield Electrical Limited | Construction | 2025 |
| Chris Sloan Limited | Professional & scientific | 2017 |
| Chrisen Maharaj Consulting Limited | Health & social care | 2014 |
| Christel Ltd | Construction | 2016 |
| Chromatic Materials Limited | Wholesale & retail | 2025 |
| Church Green Management Company Limited | Households | 2001 |
| Church Hill Trading Limited | Wholesale & retail | 2020 |
| Church Lane (Newry) Ltd | Hospitality | 2024 |
| Church Lane Coffee Ltd | Hospitality | 2017 |
| Church Meadow (Portadown) Limited | Households | 2012 |
| Church Rock Concrete Ltd | Construction | 2016 |
| Ci-Co Ltd | Administrative & support | 2025 |
| CIC Electrical Limited | Construction | 2022 |
| CID Electrical Ltd | Construction | 2024 |
| Cill Bhronai Escape Ltd | Hospitality | 2021 |
| Cinderella Consulting Limited | Real estate | 2013 |
| Cipr Contracts Ltd | Administrative & support | 2022 |
| Circus Gerbola Limited | Arts & recreation | 2025 |
| City Centre Garage Limited | Wholesale & retail | 2018 |
| City Provisons Ltd | Wholesale & retail | 2024 |
| Cityview Foods Ltd | Wholesale & retail | 2012 |
| Cityview Properties (N.I.) Ltd | Real estate | 2012 |
| Civest Ltd | Construction | 2026 |
| Civil Engineering & Management Limited | Construction | 2005 |
| CJ Aviation Limited | Transport & logistics | 2018 |
| CJ Lakeview Enterprises Ltd | Real estate | 2016 |
| CJ Lakeview LLP | | 2024 |
| CJ Mechanical Ltd | Construction | 2017 |
| CJ Trading Solutions Ltd | Wholesale & retail | 2015 |
| Cjjr Holdings Ltd | Financial services | 2025 |
| CJK Group Ltd | Construction | 2021 |
| CJN Logistics Ltd | Transport & logistics | 2021 |
| CJR Building Contractor Ltd | Construction | 2023 |
| CJT Estimating Ltd | Construction | 2025 |
| CK Asset Group Ltd | Hospitality | 2025 |
| CK Stores Ltd | Wholesale & retail | 2026 |
| CKC Holdings (N.I.) Limited | Financial services | 2018 |
| CL (NI) Building Services Ltd | Construction | 2026 |
| Cladybeg Farms Ltd | Agriculture & fishing | 2011 |
| Clanbrassil (Tollymore) Management Limited | Households | 2019 |
| Clannbridge Limited | Wholesale & retail | 2021 |
| Clanrye Abbey Developments | Real estate | 1986 |
| Clanrye CAB Company Ltd | Transport & logistics | 2017 |
| Clanrye Electrical Supplies Limited | Manufacturing | 1988 |
| Clanrye House Property Management Ltd | Households | 2022 |
| Clanrye Properties Limited | Real estate | 2016 |
| Clanrye Veterinary Clinic Limited | Professional & scientific | 2008 |
| Clanwoods Ltd | Real estate | 2026 |
| Clarbane Haulage Ltd | Transport & logistics | 2018 |
| Clarendon Dock Limited | Construction | 2017 |
| Clarify Solutions Ltd | Professional & scientific | 2018 |
| Clarion Investments Limited | Hospitality | 1992 |