| Autocruz NI Ltd | Wholesale & retail | 2023 |
| Autoslick Ltd | Wholesale & retail | 2023 |
| Avada Environmental Consultancy Ltd | Professional & scientific | 2022 |
| Avada Environmental Ltd | Water & waste | 2013 |
| Aviasource Limited | Professional & scientific | 2025 |
| Avinger Limited | Financial services | 2015 |
| Awad Property Ltd | Real estate | 2023 |
| Awad T/A Advance Windows and Doors Ltd | Manufacturing | 2022 |
| Awaken Saunas Ltd | Manufacturing | 2023 |
| Axis Creative Ltd | Professional & scientific | 2023 |
| Axon Power & Control Ltd | Manufacturing | 2000 |
| Axon Power GB Ltd | Manufacturing | 2017 |
| AZ Mproperty Ltd | Construction | 2023 |
| B & M Begley Ltd | Wholesale & retail | 2006 |
| B & R Petfoods Limited | Manufacturing | 2021 |
| B Hughes Transport Ltd | Transport & logistics | 2025 |
| B Mckenna & Sons Ltd | Agriculture & fishing | 2015 |
| B Mckernan & Co. Ltd | Financial services | 2005 |
| B&M D Retail Ltd | Wholesale & retail | 2022 |
| B&S Tools & Equipment Ltd | Wholesale & retail | 2024 |
| B.D.J. Management Limited | Real estate | 2010 |
| Back on Track (N.I.) Ltd | Health & social care | 2017 |
| Backford Transport Ltd | Transport & logistics | 2014 |
| Baim Construction Limited | Construction | 2016 |
| Baird Dungannon Ltd | Real estate | 2015 |
| Balcon Properties Limited | Real estate | 2009 |
| Bale Tape Supplies Ltd | Water & waste | 2018 |
| Ballygawley Early Years Ltd | Education | 1998 |
| Ballymacall Farms Ltd | Agriculture & fishing | 2024 |
| Ballytrodden Farms Ltd | Agriculture & fishing | 2024 |
| Ballyview Properties Ltd | Construction | 2025 |
| Bangor Meats Limited | Other services | 1969 |
| Banner Performance Ltd | Health & social care | 2024 |
| Baracuda Angling Centre Ltd | Wholesale & retail | 2018 |
| Barbers Top Class Ltd | Other services | 2023 |
| Barcon Construction Group Ltd | Construction | 2023 |
| Bardic Educational Arts & Media Limited | Arts & recreation | 2002 |
| Barn Hill Contracts Ltd | Construction | 2022 |
| Barnoe Ltd | Manufacturing | 2020 |
| Barrack Hill Quarries Limited | Mining & quarrying | 1992 |
| Barrett Group Eglish Ltd | Financial services | 2023 |
| Barrett Mcgrath Education & Mentoring Services Limited | Public administration | 2018 |
| Barrick Hill Farms Limited | Agriculture & fishing | 2007 |
| Barron Civils Ltd | Construction | 2018 |
| Bathroom Envy Ltd | Wholesale & retail | 2021 |
| Bawn Development Association | Other services | 2012 |
| BC Creations Limited | Wholesale & retail | 2021 |
| Bcgs Group Ltd | Health & social care | 2024 |
| BCL Glenavon Lane Limited | Construction | 2022 |
| Bcsni Ltd | Construction | 2022 |
| BD Refrigerated Limited | Transport & logistics | 2013 |
| Behind the Balance Sheet Ltd | Education | 2023 |
| Beiginis Holdings Limited | Hospitality | 2023 |
| Beis Pilates Ltd | Arts & recreation | 2025 |
| Bela Recruitment Ltd | Administrative & support | 2018 |
| Belfast Corporate Rentals Ltd | Real estate | 2021 |
| Belfast Office Properties Limited | Real estate | 1971 |
| Believe Brands Limited | Wholesale & retail | 2024 |
| Bellinter Holdings Ltd | Financial services | 2024 |
| Bellinter Ltd | Hospitality | 2024 |
| BEN Madigan Wood Management Company Limited | Households | 2025 |
| Benburb Holdings Ltd | Financial services | 2016 |
| Benburb Mushrooms Ltd | Real estate | 2016 |
| Benburb Priory Ltd | Arts & recreation | 2020 |
| Benburb Renewables Ltd | Energy | 2022 |
| Benkate Ltd | Real estate | 2020 |
| Beresford Square Management Co Ltd | Households | 2006 |
| Berry Brothers Acai Limited | Hospitality | 2024 |
| Bert's Pizzeria Clonoe Ltd | Hospitality | 2025 |
| Besafe Training and Consultancy Limited | Education | 2025 |
| Betty's Ice-Cream (N.I.) Ltd | Manufacturing | 2024 |
| Bhfm Ltd | Information & communication | 2015 |
| Bhmn Holdings Ltd | Professional & scientific | 2023 |
| Big Bear Stoves Ltd | Construction | 2025 |
| Binn Eadair Investments Ltd | Extraterritorial | 2026 |
| Biotricity Ltd | Other services | 2022 |
| Birch Heights Company Limited | Construction | 2016 |
| Birnie & Associates Consulting Ltd | Hospitality | 2017 |
| BJ Mcgrath Mechanical Ltd | Construction | 2019 |
| BK Dwellings Limited | Real estate | 2018 |
| Black and White Acquisitions Limited | Wholesale & retail | 2022 |
| Black Box Donuts Ltd | Hospitality | 2019 |
| Black Pepper Pizza Ltd | Hospitality | 2016 |
| Black Rhino Engineering Ltd | Manufacturing | 2026 |
| Blackbird Architecture Ltd | Professional & scientific | 2019 |
| Blackwater Community Barge Limited | Administrative & support | 2018 |
| Blackwater Haulage Limited | Transport & logistics | 2026 |
| Blackwater Medical Ltd | Manufacturing | 2020 |
| Blackwater Valley Stone Ltd | Administrative & support | 2020 |
| Blec Properties Limited | Real estate | 2021 |
| Bloomhill Farms Limited | Agriculture & fishing | 2018 |
| Bloomhill Rural Development Association | Other services | 2010 |
| Blue MAC (Manufacturing) Ltd | Manufacturing | 2013 |
| Blue Willow Springs Limited | Extraterritorial | 2011 |
| Bluechip Safety Services Ltd | Professional & scientific | 2021 |
| Bluesky NI Ltd | Administrative & support | 2009 |
| Bluesteel Engineering Ltd | Manufacturing | 2011 |
| Bluesun Software Ltd | Information & communication | 2011 |
| BM Plumbing Limited | Construction | 2025 |
| BMC Contract Services Ltd | Construction | 2024 |