| Autofleet (N.I.) Limited | Administrative & support | 2023 |
| Avanna Property Management Limited | Real estate | 2013 |
| Aventura Ltd | | 2003 |
| AW Builders Ltd | Construction | 2021 |
| Awacen Limited | Professional & scientific | 2024 |
| Azula Services Limited | Administrative & support | 2020 |
| B&R Property (N.I.) Limited | Real estate | 2015 |
| B.P. Hurrell Limited | Administrative & support | 1996 |
| Bailie Group Limited | Professional & scientific | 1964 |
| Bailie Group Property Limited | Real estate | 2000 |
| Ballyclare Car Hire Ltd | Administrative & support | 1992 |
| Ballygillen Services Limited | Manufacturing | 2026 |
| Ballylough Limited | Information & communication | 2008 |
| Ballymena Pest Control Ltd | Administrative & support | 2025 |
| Ballynamullan 1955 Limited | Extraterritorial | 2013 |
| Ballynoe Ltd | Financial services | 2023 |
| Bannview Property Ltd | Real estate | 2016 |
| Barb Holdings Limited | Financial services | 2025 |
| Barkinbear Limited | Wholesale & retail | 2024 |
| Barney's Lounge and Bar Ltd | Hospitality | 2010 |
| Barnish Electrical Ltd | Construction | 2018 |
| Barrhall Group Ltd | Real estate | 2017 |
| Barron Property Services Limited | Administrative & support | 2014 |
| Barron Transport (Holdings) Limited | Professional & scientific | 2012 |
| Barron Transport Services Ltd | Transport & logistics | 2008 |
| Basalt Group Limited | Financial services | 2021 |
| Batchbuddy Ltd | Wholesale & retail | 2018 |
| Bateson Fabrications Limited | Manufacturing | 2016 |
| Bavarian Wheel Worx Ireland Ltd | Manufacturing | 2023 |
| BE Balanced Educational Resources Limited | Wholesale & retail | 2023 |
| BE Balanced, BE YOU Limited | Health & social care | 2023 |
| Beauty Secrets at Dunadry Limited | Other services | 2015 |
| Beecomemore Ltd | Professional & scientific | 2023 |
| Belfast 247 Radio Ltd | Information & communication | 2021 |
| Belfast Bifolds & Aluminium Systems Limited | Manufacturing | 2021 |
| Belfast BIN Company Limited | Water & waste | 2025 |
| Belfast Travel Services Ltd | Other services | 2019 |
| Bell International Transport Ltd | Extraterritorial | 2022 |
| Bellissimi Aesthetics Ltd | Health & social care | 2023 |
| Belone Technical Limited | Construction | 2004 |
| BEN Neill Property Ltd | Real estate | 2026 |
| Benchworx Bespoke Joinery Ltd | Manufacturing | 2023 |
| Betchay Limited | Health & social care | 2020 |
| BF Travel Ltd | Wholesale & retail | 2026 |
| BG Soft LP | | 2018 |
| BHB Safety Specialists Ltd | Other services | 2011 |
| Biorex Diagnostics Ltd | Manufacturing | 2003 |
| Biorex Food Diagnostics Limited | Manufacturing | 2016 |
| Birch Fabrication Limited | Manufacturing | 2024 |
| Black Diamond Initiatives CIC | Education | 2026 |
| Black Park Property Limited | Real estate | 2022 |
| Blair Equity Ltd | Real estate | 2022 |
| Blanc Voile Limited | Administrative & support | 2017 |
| Bldr Ltd | Construction | 2015 |
| Blonds Salon Limited | Other services | 2016 |
| Blue Sky Freelance Ltd | Professional & scientific | 2023 |
| Bluesky Home Developments Limited | Construction | 2019 |
| BM Enterprises (Magherafelt) Ltd | Hospitality | 2017 |
| BMK Brickworks NI Ltd | Construction | 2025 |
| BNC Developments Limited | Construction | 2020 |
| Bondelivery NI Limited | Transport & logistics | 2002 |
| Boon & Beauty Limited | Wholesale & retail | 2023 |
| Booya Limited | Information & communication | 2016 |
| Braba Limited | Extraterritorial | 2024 |
| Brabat Limited | Extraterritorial | 2024 |
| Brabco Limited | Construction | 2024 |
| Brackaville Limited | Information & communication | 2023 |
| Bracken Enterprises Ltd | Wholesale & retail | 2020 |
| Bravura Developments Limited | Real estate | 1996 |
| Breezywp Ltd | Information & communication | 2025 |
| Brett Distribution Ltd | Transport & logistics | 2023 |
| Brett FBA Ltd | Professional & scientific | 2025 |
| Bricktec Contracts Limited | Construction | 2019 |
| Briden Developments Limited | Wholesale & retail | 2019 |
| Bridge Association-The | Education | 1988 |
| Bridgeview Toomebridge Ltd | Health & social care | 2004 |
| Briermount Properties Ltd | Construction | 2018 |
| Britbox (UK) Limited | Transport & logistics | 2014 |
| BSL Electrical (NI) Ltd | Energy | 2010 |
| BTS Freight Ltd | Transport & logistics | 2020 |
| Bubble & Crumble (Antrim) Limited | Hospitality | 2021 |
| Budding Designs Limited | Wholesale & retail | 2013 |
| Building Blocks Day Nursery (NI) Ltd | Health & social care | 2013 |
| Buildrite Construction & Maintenance Ltd | Construction | 2019 |
| Bumble Volley Limited | Administrative & support | 2017 |
| Bush Manor Management Company Limited | Households | 2019 |
| Businesspt Ltd | Information & communication | 2024 |
| Busy Broom Commercial Cleaning Services Limited | Administrative & support | 2023 |
| Butterfly Lodge Limited | Wholesale & retail | 2024 |
| BXB Project Ltd | Wholesale & retail | 2023 |
| C & S NI Developments Ltd | Construction | 2025 |
| C E Properties (NI) Limited | Real estate | 2005 |
| C K Car Sales Ltd | Wholesale & retail | 2007 |
| C M C Marquees Limited | Administrative & support | 2022 |
| C M Devlin Contracts Limited | Construction | 2018 |
| C. Connon Limited | Other services | 2002 |
| Caddo Retreat Limited | Health & social care | 2024 |
| Caddy Car and Commercial Limited | Wholesale & retail | 2018 |
| Caddyview Farms Limited | Agriculture & fishing | 2023 |
| Cairde Dhun Saili Ltd | Education | 2022 |