| Bluestone 74 Limited | Professional & scientific | 2024 |
| Bluklline Limited | Wholesale & retail | 2023 |
| Bluroad Trading Co Limited | Wholesale & retail | 2025 |
| Blush Wholesale Ltd | Wholesale & retail | 2024 |
| Blutail Financial Limited | Financial services | 2015 |
| BLW Lettings Ltd | Real estate | 2019 |
| BM Home Repairs and Maintenance Ltd | Administrative & support | 2025 |
| BM Kitchen Designs Limited | Manufacturing | 2023 |
| Bmah Mobiles Ltd | Wholesale & retail | 2025 |
| Bmax Holdings Ltd | Information & communication | 2021 |
| BMC Installations (2019) Ltd | Information & communication | 2019 |
| Bmca Electrical Ltd | Construction | 2024 |
| Bmca Worldwide Aviation Limited | Manufacturing | 2025 |
| Bmdn Limited | Health & social care | 2020 |
| Bmec Private Ltd | Health & social care | 2018 |
| Bmfm Ltd | Professional & scientific | 2013 |
| BMG Agencies Limited | Wholesale & retail | 2012 |
| BMG Groundwork's + Joinery Ltd | Construction | 2022 |
| BMG Group Ltd | Other services | 2008 |
| Bmgc Ltd | Professional & scientific | 2009 |
| Bmgcmchprop Ltd | Real estate | 2025 |
| Bmgcmlhprop Ltd | Real estate | 2025 |
| BMK Accounting Limited | Professional & scientific | 2015 |
| BMK Consultancy Ltd | Other services | 2023 |
| BMK Entertainment Ltd | Arts & recreation | 2020 |
| BMK Films Ltd | Information & communication | 2026 |
| BML Brickworks Ltd | Construction | 2022 |
| Bnbelfast Limited | Extraterritorial | 2018 |
| BNG Intl Ltd | Wholesale & retail | 2011 |
| BNR Ventures Limited | Manufacturing | 2024 |
| Bnrw Investments Limited | Financial services | 2024 |
| Bnywvs Ltd | Wholesale & retail | 2024 |
| BO Chef Ltd | Hospitality | 2025 |
| BO Tree Kitchen Ltd | Hospitality | 2017 |
| Bo&Arya Concept Ltd | Real estate | 2024 |
| Boadu ARE Limited | Wholesale & retail | 2024 |
| Boagnn Technology Co Limited | Wholesale & retail | 2025 |
| Board & Bottle Belfast Limited | Administrative & support | 2026 |
| Boardcom NI Ltd | Professional & scientific | 2019 |
| BOB Evans Inns Limited | Hospitality | 2017 |
| Boba Brew Limited | Wholesale & retail | 2025 |
| Bobasgrpr Ltd | Wholesale & retail | 2024 |
| Bobby's Fishmonger Limited | Wholesale & retail | 2025 |
| Bobby's Foods NI Ltd | Wholesale & retail | 2021 |
| Bobby's Sweets (NI) Ltd | Wholesale & retail | 2019 |
| Bobbys Bistro Belfast Limited | Hospitality | 2024 |
| BOC Gases Northern Ireland Limited | Other services | 2020 |
| Bode Developments Limited | Real estate | 2022 |
| Bodega Bagel Ltd | Hospitality | 2021 |
| Boden Park Coffee Roasters Limited | Manufacturing | 2019 |
| Boden- RAY Property Rentals Limited | Real estate | 2022 |
| Body Basics Belfast Limited | Other services | 2014 |
| Body Jewellery Belfast Limited | Other services | 2020 |
| Body Refinery Ltd | Arts & recreation | 2026 |
| Body Sense Physiotherapy Belfast Ltd. | Health & social care | 2015 |
| Bodytec Newtownards Limited | Wholesale & retail | 2024 |
| Bofish Limited | Manufacturing | 2024 |
| Bogan Consulting Limited | Professional & scientific | 2023 |
| Bohevny Lane Limited | Real estate | 2015 |
| Boho Hair Ltd | Other services | 2022 |
| Boiler Room Yoga Ltd | Arts & recreation | 2021 |
| BOK Consulting (N.I.) Ltd | Professional & scientific | 2018 |
| Bokat Properties Ltd | Real estate | 2004 |
| Boland Consulting Ltd | Information & communication | 2024 |
| Boland Ulster Land Limited | Construction | 1992 |
| Bolas Drinks Club Ltd | Wholesale & retail | 2024 |
| Bold Girl Productions Limited | Information & communication | 2023 |
| Boldlab Automations NI Ltd | Professional & scientific | 2026 |
| Boldstyle Limited | Wholesale & retail | 2024 |
| Bole Investments 1 Limited | Financial services | 2025 |
| Bole Investments 2 Limited | Financial services | 2025 |
| Bolfana Ltd | Health & social care | 2022 |
| Bolt Deli Ltd | Manufacturing | 2025 |
| Bolt Facilities and Contract Management Ltd | Real estate | 2024 |
| Boltmealplans.Com Ltd | Hospitality | 2022 |
| Bomb Squad Studios Ltd | Information & communication | 2023 |
| Bombay Flame Belfast Ltd | Hospitality | 2024 |
| BON Outdoor Advertising Limited | Professional & scientific | 2020 |
| Bonbon Foods UK Limited | Hospitality | 2025 |
| Bonchurch Consulting Engineers Ltd | Professional & scientific | 2011 |
| Bond Branding Studio Ltd | Professional & scientific | 2025 |
| Bond Healthcare Ltd | Administrative & support | 2013 |
| Bond Home Care Limited | Health & social care | 2026 |
| Bond International Software (UK) Limited | Information & communication | 1973 |
| Bond Search and Selection (Holding) Limited | Administrative & support | 2016 |
| Bond Search and Selection Ltd | Administrative & support | 2003 |
| Bondi Group Ltd | Financial services | 2025 |
| Bondi Pilates Ltd | Arts & recreation | 2023 |
| Boney Card Company Ltd | Wholesale & retail | 2026 |
| Bonnies Lane Management Company Limited | Extraterritorial | 2016 |
| Bonumcorpus (NO. 52) Limited | Manufacturing | 2019 |
| Bonza Ltd | Construction | 2015 |
| Boogie Limited | Wholesale & retail | 2025 |
| Boojum GB Trading Limited | Hospitality | 2017 |
| Boojum Lisburn Limited | Hospitality | 2016 |
| Boojum Ltd | Hospitality | 2007 |
| Boojum Victoria Limited | Hospitality | 2016 |
| Boojum Victoria Square Limited | Hospitality | 2016 |
| Bookable U Ltd | Information & communication | 2025 |
| Bookqi Limited | Wholesale & retail | 2024 |