| ATG Environmental Services (NI) Limited | Water & waste | 2012 |
| ATG Ground Solutions Limited | Construction | 2019 |
| ATG Services (Ireland) Ltd | Water & waste | 2007 |
| Athina Prints Ltd | Professional & scientific | 2025 |
| ATL Management Limited | Households | 2020 |
| Atlantic Coast Ltd | Construction | 2025 |
| Atlantic Kayaks Ltd | Wholesale & retail | 2020 |
| Atlantic Sands (Castlerock) Management Company Ltd | Households | 2019 |
| Augustus Property Management 2 Limited | Construction | 2013 |
| Augustus Property Management 3 Limited | Households | 2013 |
| Augustus Property Management 4 Limited | Households | 2013 |
| Augustus Property Management 5 Limited | Construction | 2013 |
| Augustus Property Management Limited | Construction | 2013 |
| Aurora Aquisitions Ltd | Arts & recreation | 2021 |
| Axon Telematics Limited | Information & communication | 2016 |
| Ayaan Services Limited | Hospitality | 2017 |
| Azafran Limited | Health & social care | 2008 |
| Azguard Ltd | Manufacturing | 2022 |
| B Kerr Transport Ltd | Transport & logistics | 2021 |
| Baileys Gate Management Ltd | Administrative & support | 2019 |
| Ballinamallard Developments Limited | Administrative & support | 2001 |
| Ballinderry Bridge Management Ltd | Households | 2019 |
| Ballintrae House Apartments Management Limited | Households | 2000 |
| Ballycanice Close Management Company Limited | Professional & scientific | 2002 |
| Ballycastle Food Stores Limited | Wholesale & retail | 2012 |
| Ballynahery Ltd | Professional & scientific | 2025 |
| Ballynahery Properties Limited | Real estate | 2021 |
| Ballyore Grove Management Company Limited | Real estate | 2004 |
| Ballyquin Investments Ltd | Health & social care | 2017 |
| Ballyrashane Meat Wholesalers Ltd | Manufacturing | 2026 |
| Ballyrashane Solar Farm Limited | Energy | 2025 |
| Ballyvennox Farm Ltd | Agriculture & fishing | 2024 |
| Bandar Developments Limited | Extraterritorial | 1979 |
| Bann System Limited | Agriculture & fishing | 2012 |
| Bann Transport Ltd | Transport & logistics | 2013 |
| Bann Valley Limited | Wholesale & retail | 2017 |
| Bann View Management Company Limited | Households | 2020 |
| Bannfield Way Management Limited | Households | 2021 |
| Bannside Dryliners Ltd | Construction | 2016 |
| Bannside Logistics Ltd | Transport & logistics | 2022 |
| Barkin Bistro Ltd | Wholesale & retail | 2020 |
| Barmouth Enterprises Limited | Real estate | 2025 |
| Barn Door Kitchen Ltd | Manufacturing | 2025 |
| Barossa Risk Control Ltd | Administrative & support | 2009 |
| Barraine Commercials Limited | Real estate | 2016 |
| Barraine Limited | Real estate | 2014 |
| Barview House Management Committee Ltd | Other services | 2007 |
| Bawnmore Court Management Limited | Extraterritorial | 1991 |
| Bayhead House Apartments Management Company Limited | Households | 2005 |
| Bayhead Management Company Limited | Households | 2011 |
| Bayview Larne Ltd | Real estate | 2026 |
| BB Engineering (NI) Limited | Manufacturing | 2003 |
| Bbaha Ltd | Health & social care | 2025 |
| Bbmca Limited | Health & social care | 2020 |
| Bbmca Properties Limited | Real estate | 2024 |
| Bbparts Ltd | Manufacturing | 2025 |
| BC Plumbing & Heating Ltd | Construction | 2015 |
| Bconnected Media Ltd | Professional & scientific | 2016 |
| BD Mullan Plumbing & Heating Ltd | Construction | 2018 |
| BE Safe GAS Services Limited | Construction | 2018 |
| Bedletni Ltd | Information & communication | 2025 |
| Bees Agricultural Solutions Limited | Manufacturing | 2017 |
| Belfast Back Care Ltd | Other services | 2019 |
| Belfast Cardiologist Limited | Health & social care | 2019 |
| Bellemont Farms Limited | Agriculture & fishing | 2015 |
| Bellisle Equestrian Limited | Wholesale & retail | 2021 |
| Bells Supermarket (Garvagh) Limited | Wholesale & retail | 2015 |
| Bellson Limited | Construction | 2007 |
| Benbane Capital Limited | Professional & scientific | 2010 |
| Benbane Limited | Real estate | 1989 |
| Benmore Gate Management Company Limited | Households | 2025 |
| Benmore Trading Limited | Administrative & support | 2006 |
| Bernice Road Management Company Limited | Households | 2016 |
| Bertie Peacock Foundation | Arts & recreation | 2007 |
| Bespoke Consultants Ltd | Other services | 2015 |
| BEY & BO Ltd | Manufacturing | 2023 |
| BHP Leasing Ltd | Administrative & support | 2022 |
| Binevenagh IT Solutions Ltd | Information & communication | 2023 |
| Biocycle Analytics Agri Limited | Professional & scientific | 2026 |
| BK Leisure Ltd | Hospitality | 2026 |
| Blackpark Management Company Limited | Households | 2003 |
| Blackrock Automation Ltd | Professional & scientific | 2017 |
| Blackrock Capital Limited | Financial services | 2010 |
| Blackstock Holdings Limited | Administrative & support | 2008 |
| Bleachgreen Apartments Limited | Extraterritorial | 2008 |
| Blindgate Limited | Real estate | 1995 |
| Bloomin’ Education CIC | Education | 2026 |
| Blubim Ltd | Information & communication | 2023 |
| Blue Giraffe Investments Limited | Real estate | 2018 |
| Blue Lace Bridal Ltd | Wholesale & retail | 2018 |
| Bluesky Resource Recovery Limited | Other services | 2008 |
| BMN Developments Ltd | Construction | 2021 |
| Bmoney Limited | Extraterritorial | 2014 |
| Bof-Es Ltd | Real estate | 2025 |
| Boghill DAM Limited | Construction | 2015 |
| Bokamoso Ltd | Health & social care | 2025 |
| Bond's Jewellers Ltd | Wholesale & retail | 2010 |
| Books Unlimited Ltd | Extraterritorial | 2018 |
| Box Displays Limited | Wholesale & retail | 2012 |
| Boxed Property Ltd | Real estate | 2021 |