| Business Primis Limited | Professional & scientific | 2018 |
| Butcher Assets Limited | Real estate | 2024 |
| Butcher Enterprises Limited | Real estate | 2024 |
| Butties Fish & Chips Limited | Hospitality | 2018 |
| BW Homes & Construction Ltd | Construction | 2001 |
| Bwsc Generation Services Northern Ireland Ltd | Energy | 2015 |
| Byrne Seafoods NI Ltd | Wholesale & retail | 2022 |
| C & G Quality Plastering Services Limited | Construction | 2015 |
| C & L Ventilation Services Limited | Manufacturing | 2020 |
| C & O Civils Ltd | Construction | 2018 |
| C Harkin Ltd | Wholesale & retail | 2024 |
| C Logue Enterprises Ltd | Wholesale & retail | 2025 |
| C P Property Projects Limited | Households | 2023 |
| C R Fishing Ltd | Agriculture & fishing | 2019 |
| C&E Electrical Ltd | Construction | 2017 |
| C&M ROE Holdings Limited | Financial services | 2025 |
| C&M ROE Properties Limited | Real estate | 2025 |
| C-Tric Limited | Health & social care | 2008 |
| C.D. Kitchens & Bedrooms Limited | Manufacturing | 1997 |
| C.Roe Contracts Limited | Construction | 2014 |
| Cabena Property (Londonderry) Limited | Real estate | 1999 |
| Caburco Limited | Real estate | 2014 |
| Cadvisory Ltd | Professional & scientific | 2025 |
| CAE Interiors Ltd | Construction | 2026 |
| Caeleri Zhiy Ltd | Wholesale & retail | 2025 |
| Cafe Storm Limited | Hospitality | 2025 |
| Calan Groundworks Limited | Construction | 2017 |
| Caldwell & Robinson Limited | Professional & scientific | 2014 |
| Callaghan's Burt NI Limited | Wholesale & retail | 2020 |
| Callander International Ltd | Administrative & support | 2019 |
| Callvid Walt Ltd | Wholesale & retail | 2024 |
| CAM Investor Limited | Financial services | 2024 |
| Camerox NI Limited | Real estate | 2021 |
| Camowen Omagh Management Company Limited | Households | 2024 |
| Campbell & Rodgers Ltd | Professional & scientific | 2018 |
| Campbell AV Consulting Limited | Real estate | 2019 |
| Campbell, Farren, Diamond Asset Holdings Ltd | Real estate | 2021 |
| Camport Ltd | Real estate | 2021 |
| Campsey Construction Ltd | Construction | 2019 |
| Campsie Autobody Ltd | Wholesale & retail | 2022 |
| Campsie Autosalvage Ltd | Wholesale & retail | 2025 |
| Campsie Business Park Management Limited | Real estate | 1991 |
| Campsie Carwash & Valet Centre Ltd | Administrative & support | 2024 |
| Campsie Developments (NI) Limited | Construction | 2024 |
| Campsie Four Limited | Real estate | 2024 |
| Campsie Indoor Ltd | Arts & recreation | 2014 |
| Campsie Motor Factors Ltd | Wholesale & retail | 2007 |
| Campsie One Limited | Financial services | 2017 |
| Campsie Real Limited | Real estate | 1985 |
| Campsie Technical Engineering Ltd | Manufacturing | 2024 |
| Campsie Two Limited | Real estate | 2019 |
| Can-I Business Limited | Agriculture & fishing | 2014 |
| Can-Tech Elastomers Ltd | Manufacturing | 2011 |
| Cannon Assets Ltd | Financial services | 2022 |
| CAP Adaptor Ltd | Wholesale & retail | 2023 |
| Captain Kirk Enterprises Limited | Wholesale & retail | 2003 |
| Car Lease 4U Limited | Wholesale & retail | 2012 |
| Car Seat Covers Direct Limited | Manufacturing | 2014 |
| Cara an Chroí Ltd | Other services | 2025 |
| Carbe Dyeco Ltd | Wholesale & retail | 2024 |
| Cardano Properties Limited | Manufacturing | 2024 |
| Caremm Limited | Hospitality | 2012 |
| Carlin Decorators Ltd | Construction | 2013 |
| Carlin Drinks Ltd | Wholesale & retail | 2025 |
| Carlin Partitions Ltd | Construction | 2025 |
| Carlin Property Investments Ltd. | Real estate | 2024 |
| Carlisle Road Properties Limited | Real estate | 2005 |
| Carlisle Ventures Ltd | Real estate | 2016 |
| Carnanreagh Investments Limited | Real estate | 2019 |
| Carol's Stock Market Limited | Manufacturing | 2018 |
| Carpet Centre (Derry) Limited | Real estate | 1992 |
| Carrickmaquigley Construction UK Ltd | Construction | 2024 |
| Carrowreagh Consulting Limited | Professional & scientific | 2017 |
| Carrowreagh Ltd | Construction | 2016 |
| Casa Petra Ltd | Wholesale & retail | 2026 |
| Casey & Sons Property Limited | Real estate | 2024 |
| Cashel 88 Ltd | Wholesale & retail | 2025 |
| Castle Gate Housing Ltd | Real estate | 2023 |
| Castlegate Lodge Limited | Hospitality | 2023 |
| Castlehill Pension Trustees Limited | Financial services | 2021 |
| Castlewater Gardens Management Company Limited | Households | 2018 |
| Castlewater Wood Management Company Limited | Households | 2019 |
| Catalyst Property Group Limited | Real estate | 2024 |
| Catchyco Ltd | Professional & scientific | 2021 |
| Cathal Kelly Limited | Manufacturing | 2022 |
| Causeway Leisure Services Limited | Households | 1990 |
| Causeway Sensory Global Ltd | Manufacturing | 2021 |
| CAW Properties Limited | Construction | 2001 |
| Caw/Nelson Drive Action Group | Other services | 2007 |
| CBD Consulting Ltd | Financial services | 2024 |
| Cbnb Builders Limited | Construction | 2018 |
| Ccewc Limited | Professional & scientific | 2026 |
| CCO (INT) Ltd | Professional & scientific | 2011 |
| CCO Business (INT) Coaching Limited | Professional & scientific | 2019 |
| CCV Investments Limited | Real estate | 2015 |
| CCV Sales Ltd | Wholesale & retail | 2017 |
| Cdcx Limited | Professional & scientific | 2025 |
| Cdoc 42 Ltd | Financial services | 2020 |
| Cdtr Limited | Real estate | 2024 |
| Cedel Communications Limited | Information & communication | 2015 |