| Ballindrum Farm Ltd | Real estate | 2023 |
| Ballygood (NO 1) Limited | Construction | 2019 |
| Ballygood Developments Ltd | Construction | 2018 |
| Ballygood Homes Ltd | Real estate | 2014 |
| Ballygood Investments Ltd | Construction | 2013 |
| Ballygood Properties Ltd | Real estate | 2014 |
| Ballygruby Investments Ltd | Financial services | 2019 |
| Ballyloughan Eggs Ltd | Agriculture & fishing | 2022 |
| Ballymoretree Ltd | Real estate | 2023 |
| Bancran Investments Ltd | Real estate | 2023 |
| Bancran Property Ltd | Real estate | 2022 |
| Bangor Leisure Ltd | Arts & recreation | 2001 |
| Barcro Ltd | Construction | 2017 |
| Bateson Bros Ltd | Construction | 2011 |
| Batfo Limited | Financial services | 2026 |
| Baymore Investments Limited | Other services | 1993 |
| BC Plumbing & Heating Contracts Ltd | Construction | 2020 |
| BEACON13 Limited | Information & communication | 2015 |
| Beam Vacuum Systems Limited | Administrative & support | 1999 |
| Beeches Crescent Company Limited | Construction | 2019 |
| Beeches Drive Company Limited | Hospitality | 2016 |
| Beechill View Properties Ltd | Real estate | 2004 |
| Beechtree Garden Centre Ltd | Administrative & support | 2020 |
| Belderra Ltd | Professional & scientific | 2026 |
| Belfastpropertyco Ltd | Real estate | 2026 |
| Belfmore Investments Ltd | Extraterritorial | 2021 |
| Bellaghy Womens Group Limited | Education | 1997 |
| Beoga Limited | Information & communication | 2017 |
| Bertie's Bakery Limited | Manufacturing | 2019 |
| Bethesda Grace | Other services | 2017 |
| Beyond Borders Film Limited | Professional & scientific | 2020 |
| Bienvenidos Ltd | Hospitality | 2023 |
| Bienvenidosni Ltd | Hospitality | 2026 |
| Bintrak Ltd | Information & communication | 2025 |
| Birch Mount Company Ltd | Arts & recreation | 2025 |
| Birch Tree Company NO 5 Limited | Extraterritorial | 2014 |
| Birch Village Company Limited | Professional & scientific | 2016 |
| BK Energy Ltd. | Energy | 2015 |
| Black Quarter Properties Ltd | Construction | 2001 |
| Blackline Styling Ltd | Manufacturing | 2021 |
| Blackrock Farm Ltd | Agriculture & fishing | 2026 |
| Blackthorn Terrace Company Limited | Extraterritorial | 2022 |
| Bleach Green Lane Ltd | Professional & scientific | 2016 |
| Bloc Labs Ltd | Manufacturing | 2021 |
| Bloc PPE Ltd | Manufacturing | 2020 |
| Blossom Health N.I Limited | Health & social care | 2022 |
| BLS Medical Limited | Health & social care | 2016 |
| Blue Savannah Retail Limited | Wholesale & retail | 2022 |
| BMC Engineering Solutions (NI) Limited | Construction | 2016 |
| BMP Contracts Ltd | Construction | 2013 |
| BMR Contracts (NI) Ltd | Construction | 2013 |
| BMR Facades Ltd | Financial services | 2024 |
| Booze Bandits Ltd | Hospitality | 2024 |
| Boss Gym Magherafelt Ltd | Arts & recreation | 2024 |
| Bounce-Abouts Ltd | Arts & recreation | 2003 |
| Box-It Ireland Document Management Ltd | Administrative & support | 2006 |
| Boxdocs Ltd | Administrative & support | 2018 |
| Bradleys Corner Limited | Wholesale & retail | 2022 |
| Braidside Meadows Management Company Limited | Households | 2025 |
| Brendan Scullion Construction Limited | Construction | 2014 |
| Bright Beginnings MID Ulster Ltd | Health & social care | 2023 |
| Briony Property Developments Ltd | Extraterritorial | 2006 |
| Broderick's Optical Limited | Wholesale & retail | 2022 |
| Brogan Coaching Ltd | Wholesale & retail | 2026 |
| Brooklands Altnagelvin NO.2 Limited | Energy | 2015 |
| Brooklands Healthcare (Altnagelvin) Limited | Extraterritorial | 2012 |
| Brookvale Associates (N.I.) Limited | Real estate | 2016 |
| Brough Village Company Limited | Health & social care | 2019 |
| Brwe Ltd | Energy | 2012 |
| Bryson's Bar and Restaurant Limited | Hospitality | 2017 |
| BT Dermatology Ltd | Health & social care | 2024 |
| Bt's Pizza Ltd | Hospitality | 2026 |
| BT45 - the Collective Ltd | Other services | 2019 |
| BT45 Academy Ltd | Other services | 2017 |
| Bubbly Sips 2 Limited | Hospitality | 2023 |
| Bunny and Birdy Ltd | Wholesale & retail | 2022 |
| Business Success Strategies Ltd | Wholesale & retail | 1993 |
| Byte IT Security Systems Ltd | Information & communication | 2020 |
| C & D Electrical (N.I.) Limited | Construction | 2016 |
| C & D Paving and Groundworks (NI) Limited | Administrative & support | 2015 |
| C Bradley Ltd | Construction | 2025 |
| C Campbell Aesthetics Ltd | Health & social care | 2026 |
| C D M Construction (N.I.) Ltd | Extraterritorial | 1999 |
| C H E (Castledawson) Ltd | Construction | 2023 |
| C Kelly Contracts Ltd | Construction | 2014 |
| C Wilson Electrics Ltd | Construction | 2026 |
| Cabinspace Ltd | Construction | 2017 |
| Caden Developments Ltd | Construction | 2026 |
| Cahore Holdings Limited | Professional & scientific | 2014 |
| Cairde Screen | Other services | 2010 |
| CAM Plant & Machinery Ltd | Construction | 2005 |
| Cambium Innovation Ltd | Professional & scientific | 2023 |
| Cameron Turbine Ltd | Energy | 2015 |
| Canole Property Group Ltd | Real estate | 2025 |
| Carabos Trading Limited | Hospitality | 2005 |
| Caraman Limited | Construction | 2005 |
| Care Circle Home Management Limited | Health & social care | 2006 |
| Care Circle Management Limited | Professional & scientific | 2013 |
| Caree Property Holdings Limited | Real estate | 2023 |
| Carmean Investments Limited | Real estate | 2023 |