| Cable Consultants Limited | Construction | 1996 |
| CAD Designs 625 Limited | Wholesale & retail | 2016 |
| Cadshaw Developments Limited | Construction | 2011 |
| Cafe 67 of County Down Limited | Hospitality | 2025 |
| Cagayan Power Limited | Health & social care | 2026 |
| Caishen Recruitment Ltd | Administrative & support | 2026 |
| Cajp Ltd | Hospitality | 2025 |
| Cakmak 68 Limited | Hospitality | 2025 |
| Calcium Bidco Limited | Financial services | 2024 |
| Calcium Midco Limited | Financial services | 2024 |
| Californialilac Ltd | Financial services | 2025 |
| Callaghan-Hayes Ltd | Health & social care | 2013 |
| Callinan Corporate Consultancy Limited | Professional & scientific | 2021 |
| Cals-S UK Limited | Administrative & support | 2014 |
| Caltherm U.K. Limited | Manufacturing | 1979 |
| CAM Installations Electrical Solutions Limited | Construction | 2017 |
| Camden Luxe Apartments Ltd | Hospitality | 2025 |
| Cameron Blake Ltd | Professional & scientific | 2014 |
| Cami Estates Limited | Real estate | 2026 |
| Campos Medical Aesthetics Studio Ltd | Health & social care | 2025 |
| Canicula Group Ltd | Wholesale & retail | 2020 |
| Cannville Holdings Ltd | Hospitality | 2025 |
| Canofield Ventures Limited | Wholesale & retail | 2005 |
| Can’D Productions Ltd | Professional & scientific | 2019 |
| Capewell Davis Commercial Limited | Wholesale & retail | 2015 |
| Capital Solutions Group Ltd | Financial services | 1999 |
| Car & Commercial Contracts (Stoke) Limited | Wholesale & retail | 2010 |
| Car Atelier Limited | Wholesale & retail | 2025 |
| Car Energy Logistics Limited | Transport & logistics | 2022 |
| Car Expert Trans Limited | Transport & logistics | 2026 |
| Car X Auto Services Ltd | Manufacturing | 2016 |
| Carboncalc Ltd | Professional & scientific | 2026 |
| Care Guard Group Ltd | Manufacturing | 2024 |
| Carenest Healthcare Ltd | Health & social care | 2026 |
| Cariad Chiropractic Ltd | Health & social care | 2026 |
| Caring Focus Limited | Health & social care | 2021 |
| Carletto's (N.I.) Ltd | Hospitality | 2018 |
| Carlingford Lough Pilots Ltd | Transport & logistics | 2006 |
| Carls Mart Ltd | Wholesale & retail | 2026 |
| Carlton Dewhirst Ltd. | Manufacturing | 2017 |
| Carn Hill Management Company Limited | Households | 2021 |
| Carnival of Eternal Light Ltd | Arts & recreation | 2016 |
| Caroline Pill Consulting Limited | Professional & scientific | 2020 |
| Carpet Track Limited | Manufacturing | 2003 |
| Carroll MC Limited | Hospitality | 2018 |
| Cartenio Ltd | Professional & scientific | 2024 |
| CASITA26 Limited | Real estate | 2026 |
| Cask Developments Ltd | Real estate | 2024 |
| Castillo Pools Limited | Arts & recreation | 2014 |
| Castle Back Limited | Construction | 2016 |
| Castle Bitez Ltd | Hospitality | 2025 |
| Castle Comfort Centre Ltd | Extraterritorial | 2018 |
| Castle Comfort Stairlifts Limited | Wholesale & retail | 2003 |
| Castle Construction (Staffs) Ltd | Construction | 2011 |
| Castle Contracts (Newcastle) Ltd | Construction | 2016 |
| Castle Express Ltd | Hospitality | 2024 |
| Castle Hydroponics Limited | Wholesale & retail | 2010 |
| Castle Pathway School CIC | Education | 2026 |
| Castle Supps Limited | Wholesale & retail | 2024 |
| Castle Supps Online Limited | Wholesale & retail | 2024 |
| CASTLE4X4 Ltd | Wholesale & retail | 2025 |
| Castleridge Management Company Limited | Households | 1986 |
| Castlewellan Community Allotments Limited | Agriculture & fishing | 2023 |
| Cataucv Ltd | Wholesale & retail | 2018 |
| CATER4 (Catering) Ltd | Hospitality | 2011 |
| Cathro Compressors Limited | Manufacturing | 2003 |
| Caudwell Children | Administrative & support | 1999 |
| CB Beauty Centre Ltd | Other services | 2024 |
| CBT With ME Ltd | Health & social care | 2024 |
| Ccaz Limited | Wholesale & retail | 2025 |
| CCG D&B Limited | Construction | 2015 |
| CD Consultants and Advisory Solutions Limited | Health & social care | 2025 |
| CD Solar NI Ltd | Construction | 2025 |
| Cedar Grove Management Services Limited | Real estate | 2008 |
| Celestial Recordings Limited | Information & communication | 2010 |
| Central Promenade Management Limited | Households | 2009 |
| Centre 61 Ministries | Other services | 2020 |
| Centrex Properties Limited | Households | 1987 |
| Century Leisure Ltd | Wholesale & retail | 2024 |
| Ceramic Restoration Studios Limited | Other services | 2004 |
| Certbase Ltd | Information & communication | 2019 |
| Certo Recruitment Limited | Administrative & support | 2019 |
| CG Kind Care Ltd | Administrative & support | 2019 |
| Chadca Early Years Playgroup Community Interest Company | Education | 2012 |
| Chaircraft Limited | Real estate | 1954 |
| Chamberlin Automotive Ltd | Wholesale & retail | 2018 |
| Chamco Consulting Limited | Professional & scientific | 2024 |
| Change for Children Limited | Professional & scientific | 2025 |
| Charles Whalley Advertising Limited | Professional & scientific | 2015 |
| Charlie Follows Yoga Ltd | Education | 2026 |
| Charlotte Gardiner Ltd | Arts & recreation | 2014 |
| Charlotte House Asset Holdings Limited | Financial services | 2014 |
| Chartel Ltd | Administrative & support | 2009 |
| Charter Capital Limited | Financial services | 2024 |
| Charter Invest Limited | Professional & scientific | 2023 |
| Chartered Estates (Commercial) Limited | Real estate | 1991 |
| Charterhouse Legal Limited | Professional & scientific | 2024 |
| CHAT1 Information & Technology Limited | Manufacturing | 2013 |
| Chateau Nouveau Newcastle Ltd | Hospitality | 2026 |
| Chatha Property Holdings Ltd | Real estate | 2023 |