| Basthm Ltd | Wholesale & retail | 2025 |
| Bastide Ventures Ltd | Construction | 2015 |
| Bates Brothers Ltd | Water & waste | 1990 |
| Bates Property Investments Ltd | Administrative & support | 2017 |
| Bates Recovery Limited | Wholesale & retail | 2013 |
| Batesy Biomass Group Limited | Wholesale & retail | 2019 |
| Batesy Farm & Equestrian Limited | Agriculture & fishing | 2021 |
| Batesy Recycling Limited | Extraterritorial | 2011 |
| Batesy Skip Hire Limited | Extraterritorial | 1999 |
| Batesy Waste Management Ltd | Water & waste | 1990 |
| Batik Moderna Furniture Ltd | Wholesale & retail | 2023 |
| Batik Moderna Interiors Ltd | Wholesale & retail | 2019 |
| Battisti Hairdressing Limited | Other services | 2005 |
| Battle Inc. Gaming CIC | Wholesale & retail | 2022 |
| Batyre Limited | Wholesale & retail | 1966 |
| BAU Property Services Limited | Real estate | 2023 |
| Bawn Provisions Ltd | Manufacturing | 2026 |
| Bawnard Properties LLP | | 2020 |
| Bawnmore Properties Limited | Real estate | 2015 |
| Baxter Engineering N.I. Limited | Professional & scientific | 2026 |
| Baxter Murray Ltd | Manufacturing | 2011 |
| Baxterworld Limited | Professional & scientific | 2011 |
| Bay Apartments Management Ltd | Households | 2001 |
| Bay Close NI Management Company Limited | Households | 2022 |
| Bay Leaves Belfast Ltd | Hospitality | 2018 |
| Bay Road Management Company Limited | Households | 2007 |
| Bay View Developments ( IRE) Limited | Construction | 2025 |
| Bayit Property Lettings Ltd | Real estate | 2025 |
| Bayoadedokun Ltd | Health & social care | 2024 |
| Bayswater Developments Limited | Real estate | 2005 |
| Bayview Media Limited | Information & communication | 2016 |
| BB7 Risk Advisory Limited | Construction | 2019 |
| Bbangya Ltd | Wholesale & retail | 2025 |
| Bbcbjioe Ltd | Manufacturing | 2024 |
| Bbeco Ltd | Financial services | 2024 |
| Bbhugme AS Ltd | Wholesale & retail | 2024 |
| BBJ Commercial Limited | Real estate | 2020 |
| BBJ UMA Ltd | Wholesale & retail | 2024 |
| BBL Logistics & Solutions Ltd | Transport & logistics | 2019 |
| BBQ 22 Ltd | Hospitality | 2024 |
| BBS (NI) Limited | Professional & scientific | 2014 |
| BBS Plumbing and Heating Services Ltd | Construction | 2025 |
| BC Management Services Limited | Professional & scientific | 2021 |
| BC Packaging Services Ltd | Manufacturing | 2018 |
| BC Plastering Contracts (N.I.) Limited | Construction | 2021 |
| BC Property Sales Ltd | Real estate | 2022 |
| BC TMA 2 Limited | Financial services | 2018 |
| BCD Perry Limited | Financial services | 2012 |
| BCF Handling Ltd | Wholesale & retail | 2022 |
| Bcgc Ltd | Arts & recreation | 2012 |
| BCL Industrial Concrete Floors Limited | Construction | 2014 |
| BCM (2019) Ltd | Construction | 2019 |
| BCN Managed Limited | Information & communication | 2000 |
| Bcni Limited | Hospitality | 2019 |
| BCO Advisory Ltd | Administrative & support | 2017 |
| BCS Belfast Ltd | Real estate | 2026 |
| BCT N.I. C.I.C. | Education | 2016 |
| BD Properties (2024) Ltd | Real estate | 2024 |
| BD Solar Solutions Limited | Construction | 2022 |
| BDB Films Ltd | Information & communication | 2017 |
| Bdftez Limited | Wholesale & retail | 2024 |
| BDI Media Ltd | Information & communication | 2025 |
| Bdic Medtech Limited | Professional & scientific | 2023 |
| Bdkl Ltd | Wholesale & retail | 2024 |
| BDL Contracts Ltd | Other services | 2015 |
| BDM Accountancy Limited | Professional & scientific | 2004 |
| BDO NI Chartered Accountants (Holdings) Limited | Extraterritorial | 2015 |
| BDO NI Chartered Accountants Limited | Extraterritorial | 2015 |
| BDO NI Outsourcing Limited | Other services | 2010 |
| BDR Consulting Limited | | 2002 |
| BDT Ecommerce Limited | Wholesale & retail | 2024 |
| BE Able to Trading Ltd | Wholesale & retail | 2024 |
| BE Sound Productions Ltd | Hospitality | 2025 |
| BE Sundries Hair and Beauty Ltd | Other services | 2023 |
| BEA Josol Limited | Health & social care | 2022 |
| Beach House Developments N I Ltd | Construction | 2021 |
| Beaches (Newcastle) Limited - the | Extraterritorial | 2007 |
| Beachview Properties Ltd | Real estate | 2022 |
| Beacon Certification Limited | Administrative & support | 2022 |
| Beacon Engineering Services Limited | Professional & scientific | 2015 |
| Beacon Fire & Security (NI) Limited | Administrative & support | 2012 |
| Beacon Management Consulting Limited | Professional & scientific | 2023 |
| Beacon NI Property Ltd | Real estate | 2025 |
| Beagbiz Devops Service Ltd | Information & communication | 2021 |
| Beagh Limited | Professional & scientific | 2017 |
| Beakon Limited | Information & communication | 2023 |
| Bealard Limited | Real estate | 2014 |
| Beam Benefits NI Ltd | Information & communication | 2025 |
| Beam Property Services Limited | Construction | 2009 |
| Beammjack Limited | Health & social care | 2017 |
| Bean Brewed NI Ltd | Hospitality | 2018 |
| Bean Machine (Northern Ireland) Limited - the | Administrative & support | 1999 |
| Beannchor Finco Holdings Limited | Administrative & support | 2026 |
| Beannchor Finco Limited | Professional & scientific | 2026 |
| Beannchor Group Limited | Hospitality | 2018 |
| Beannchor HO Holdings Limited | Hospitality | 2026 |
| Beannchor HO Limited | Real estate | 2007 |
| Beannchor Holdings Limited | Hospitality | 2026 |
| Beannchor Limited | Hospitality | 1993 |
| Beannchor NO. 1 Limited | Hospitality | 2013 |