| BF Accountancy Ltd | Professional & scientific | 2026 |
| BH Property Brothers Holdings Limited | Professional & scientific | 2023 |
| BH Property Brothers Kensington Limited | Wholesale & retail | 2023 |
| BH Property Brothers Ltd | Real estate | 2021 |
| BH Property Brothers PB Limited | Wholesale & retail | 2023 |
| Bigjolly Management Ltd | Information & communication | 2015 |
| Bio-Materials Hub NI Ltd | Other services | 2024 |
| Biogen Distributors Limited | Water & waste | 2011 |
| Bishopscourt Diff and Drift Ltd | Arts & recreation | 2023 |
| Black Medicine Films Ltd | Information & communication | 2019 |
| Blackbox Requirements Ltd | Information & communication | 2015 |
| Blackwater Engineering Limited | Manufacturing | 1998 |
| Blackwater Integrated College Limited | Education | 2008 |
| Blood Trans UK Ltd | Transport & logistics | 2018 |
| Bluewater Financial Planning Limited | Professional & scientific | 2002 |
| Blythe Real Estate Management Ltd | Real estate | 2021 |
| BME Ltd | Energy | 2016 |
| BPF Road Safety Limited | Construction | 1982 |
| Bradford Contracts Ltd | Construction | 2025 |
| Braniff Lettings Ltd | Households | 2025 |
| Braniff Properties LLP | | 2026 |
| Branson Corporation Limited | Extraterritorial | 1993 |
| Brennans Ltd | Wholesale & retail | 2004 |
| Brian Clendinning Limited | Financial services | 2023 |
| Bridgeview Residential Home Ltd | Health & social care | 2015 |
| Bright Community Association Limited | Arts & recreation | 2004 |
| Bright Mechanical Ltd | Construction | 2026 |
| Brightdent Ltd | Education | 2019 |
| Brightstar (N.I.) Limited | Wholesale & retail | 2019 |
| Brooklynave Ltd | Real estate | 2022 |
| Bror Club Ltd | Wholesale & retail | 2025 |
| Brothers Autism Social Enterprise Community Interest Company | Health & social care | 2023 |
| Brown Estates Ltd | Real estate | 2019 |
| Browne's GAS Services Limited | Wholesale & retail | 2022 |
| Bucknall.Info Ltd | Professional & scientific | 2016 |
| Build Insite Ltd | Information & communication | 2026 |
| Bulgarian Shop Ivayla Ltd | Wholesale & retail | 2025 |
| Burger Bros Ballykinlar Ltd | Hospitality | 2025 |
| BUY2LETPROPERTYINVESTMENTS Ltd | Real estate | 2025 |
| BV Apiary Equipment Limited | Manufacturing | 2025 |
| Byrne Construction Ltd | Construction | 2013 |
| C & C Flanagan Contracts Ltd | Construction | 2026 |
| C & C Seafoods Limited | Agriculture & fishing | 2025 |
| C & P Flanagan Contracts Limited | Administrative & support | 2018 |
| C Johnston & Co Ltd | Professional & scientific | 2018 |
| C Mason Engineering & Co Ltd | Manufacturing | 2023 |
| C R Catering (2024) Ltd | Hospitality | 2024 |
| C&A Bell Ltd | Construction | 2022 |
| C. Mccreesh Bricklaying Limited | Construction | 2015 |
| C. REA Brickwork Restoration Specialists Ltd | Construction | 2024 |
| C9 Property Investments Ltd | Construction | 2025 |
| Calbeth Consultancy Limited | Education | 2013 |
| Callan Insulation Limited | Construction | 2011 |
| Campbell Management Services Limited | Construction | 1986 |
| Candy & Co Group Limited | Professional & scientific | 2022 |
| Cannings of Limavady (Motors) Limited | Real estate | 1978 |
| Capall Mara Consulting (N.I.) Limited | Professional & scientific | 2023 |
| Carellen Holdings Ltd | Real estate | 2017 |
| Carive Limited | Wholesale & retail | 1998 |
| Carlin Ventures Ltd | Information & communication | 2024 |
| Carvana Cars Limited | Wholesale & retail | 2024 |
| Carville Tyres Ltd | Wholesale & retail | 2025 |
| Cash Cars & Lucky Stars Ltd | Information & communication | 2025 |
| Cassano Consultancy Limited | Professional & scientific | 2007 |
| Castlewellan Property Investments Ltd | Real estate | 2019 |
| CC Fire Safety Ltd | Public administration | 2026 |
| Cedar Integrated Primary School Limited | Education | 1994 |
| Central Garages (Crossgar) Ltd | Wholesale & retail | 1990 |
| Centrepoint Entertainment Limited | Arts & recreation | 2017 |
| Chambers Survey Solutions Ltd | Information & communication | 2019 |
| Charger Films Ltd | Information & communication | 2024 |
| Charles Rourke & Sons Funeral Directors Ltd | Other services | 2015 |
| Charlies Place Ltd | Education | 2025 |
| Chenergy Ltd | Manufacturing | 2025 |
| Cj's Fish & Chip 25A Limited | Hospitality | 2025 |
| CJL Roofing Ltd | Construction | 2018 |
| CL Jones Construction Limited | Construction | 2015 |
| Claragh Consulting Limited | Professional & scientific | 2023 |
| Claragh Limited | Real estate | 2013 |
| Clear Marketing & Media Limited | Professional & scientific | 2019 |
| Clendinning Claim Consultants (NI) Limited | Financial services | 2016 |
| Cleveland-Northern Ireland International Basketball Academy | Education | 2025 |
| Clickd Ltd | Information & communication | 2025 |
| Clough Old School Ltd | Arts & recreation | 2012 |
| Clubsec Management Limited | Administrative & support | 2003 |
| CM Precision Components Ltd | Manufacturing | 2006 |
| CMAC24 Ltd | Construction | 2026 |
| Coach Horse Lane Management Company Limited | Households | 2007 |
| CODO8 | Manufacturing | 2020 |
| Commercial Connections Limited | Construction | 2003 |
| Companiesbiz Ltd | Wholesale & retail | 2016 |
| Complete Access Solutions Ltd | Construction | 2013 |
| Coney Island Leisure Limited | Hospitality | 2025 |
| Corbally Hill Limited | Information & communication | 2014 |
| Cosy (Hampton) Limited | Construction | 2025 |
| Cosy Group Bidco Limited | Financial services | 2025 |
| Cosy Group Holdings Limited | Financial services | 2017 |
| Cosy Roof (UK) Ltd | Construction | 2018 |
| Cosy Roof Developments Limited | Construction | 2017 |
| Cosyinsulation Limited | Construction | 2017 |