| Blue Horizon Property Holdings Ltd | Real estate | 2025 |
| Blue Moss Limited | Professional & scientific | 2017 |
| Bluechip Editing Ltd | Information & communication | 2025 |
| Blueoak Equestrian Ltd | Agriculture & fishing | 2025 |
| Blueprint Development Consultancy Limited | Professional & scientific | 1999 |
| Bluesky Cleaning Ltd | Other services | 2022 |
| Bmby Ltd | Professional & scientific | 2019 |
| BMC Electrical Contracts Ltd | Construction | 2013 |
| Bmca Solutions Limited | Administrative & support | 2010 |
| BMF Business Services Ltd | Administrative & support | 1996 |
| BMK Electrics Ltd | Construction | 2023 |
| BNL Productions Ltd | Information & communication | 2016 |
| BNR Stores Limited | Wholesale & retail | 2017 |
| Bocombra Developments Limited | Construction | 2010 |
| Bocombra Park Portadown Management Limited | Households | 2024 |
| Boconnell Construction Limited | Construction | 2019 |
| Bodybyora Ltd | Education | 2025 |
| Bodyfit Mums Ltd | Arts & recreation | 2017 |
| Bodyworxni.Com Limited | Wholesale & retail | 2017 |
| Bollardsplus Protective Systems Ltd | Construction | 2022 |
| Bolt AAM Limited | Other services | 2024 |
| Bordessa Limited | Professional & scientific | 2024 |
| Boss Lady Taxis Limited | Transport & logistics | 2022 |
| Boss Mechanical Services Limited | Construction | 2018 |
| Bowens Meadow Management Limited | Households | 2010 |
| Box Consulting Ltd | Professional & scientific | 2013 |
| Boyce Precision Engineering Ltd | Manufacturing | 2006 |
| Boyd Technology Solutions Ltd | Information & communication | 2025 |
| Boyles Trading Limited | Hospitality | 2012 |
| BP Plumbing Heating & GAS Services Ltd | Construction | 2026 |
| BPF Developments Limited | Real estate | 2013 |
| BPS Group Protection Limited | Financial services | 2014 |
| Bracken Hall Management Ltd | Households | 2017 |
| Bradco Enterprises Ltd | Professional & scientific | 2025 |
| Bradley Shoots Ltd | Professional & scientific | 2022 |
| Braemore Energy Ltd | Energy | 2026 |
| Bramley Bacon Limited | Extraterritorial | 2009 |
| Bramley Leisure Ltd | Arts & recreation | 2023 |
| Bramley Meadows (Clonmore) Limited | Households | 2015 |
| Brand Connect Promotions Ltd | Other services | 2023 |
| Branded Beef Breeders (N.I.) Limited | Agriculture & fishing | 2023 |
| Branded Merch Ltd | Manufacturing | 2024 |
| Bravo Tango Coffee Limited | Manufacturing | 2021 |
| Brayhill Ireland Limited | Real estate | 2024 |
| Breeze Construction Solutions Limited | Construction | 2014 |
| Breezy Hill Wind Ltd | Energy | 2012 |
| Breile Limited | Wholesale & retail | 2022 |
| Bremeton Ltd | Professional & scientific | 2025 |
| Brew (MOY) Limited | Hospitality | 2018 |
| Bright Horizon Group Limited | Construction | 2025 |
| Brightstars (NI) Ltd | Other services | 2012 |
| Brnt Media Limited | Information & communication | 2025 |
| Broad View EA Ltd | Information & communication | 2023 |
| Broadcast Direct Ltd | Wholesale & retail | 2024 |
| Broadwater Design Limited | Professional & scientific | 2025 |
| Brontek Ltd. | Wholesale & retail | 2019 |
| Brookdale Trading Ltd | Wholesale & retail | 2023 |
| Brookfield Properties Ireland Limited | Real estate | 2006 |
| Brookport Limited | Real estate | 2004 |
| Broomhill Estates Limited | Households | 2002 |
| Broomhill Group Holdings Ltd | Real estate | 2007 |
| Broomhill Properties (Leeds) Limited | Real estate | 2006 |
| Broomhill Properties (Magheralin) Ltd | Real estate | 2000 |
| Broomhill Properties (VDL) Ltd | Real estate | 2007 |
| Broomhill Properties Belfast Limited | Real estate | 2021 |
| Brownlee Preserves Ltd. | Manufacturing | 2014 |
| Brownlow Heat Transfer Limited | Energy | 2001 |
| Brownlow Industrial Developments Ltd | Real estate | 2014 |
| Brownlow Limited | Administrative & support | 1989 |
| Brownstown Community Development Limited | Arts & recreation | 2025 |
| Brunch 'N' Brew N.I. Ltd | Hospitality | 2022 |
| Brutxl Ltd | Professional & scientific | 2026 |
| Bryan Hynds Garden Machinery Limited | Wholesale & retail | 2010 |
| BS Developments (NI) Ltd | Construction | 2003 |
| Bubblt Limited | Hospitality | 2023 |
| Buck Eejit Games Ltd | Information & communication | 2022 |
| Buckley Health and Safety Ltd | Professional & scientific | 2020 |
| Building Compliance Testing & Surveying Ltd | Professional & scientific | 2017 |
| Built Different Properties Ltd | Real estate | 2026 |
| Burger Haus Limited | Hospitality | 2025 |
| Burke Shipping Services Limited | Agriculture & fishing | 1970 |
| Burkes Agri Supplies Ltd | Wholesale & retail | 2014 |
| Burkes of Cornascriebe (2014) Limited | Wholesale & retail | 2014 |
| Burn Brae Crescent Management Ltd | Households | 2017 |
| Burning Desires Portadown Limited | Wholesale & retail | 2016 |
| Bushe Commercial Limited | Professional & scientific | 2025 |
| Business Protection Solutions (UK) Limited | Financial services | 2010 |
| Businesswiseni Ltd | Professional & scientific | 2020 |
| Buttermarket Leisure Ltd | Arts & recreation | 2023 |
| Buywell Properties Limited | Real estate | 1965 |
| C & R Services Moira Ltd. | Construction | 2014 |
| C M L Contracts Ltd | Construction | 2021 |
| C Mallon Butchers Limited | Wholesale & retail | 2023 |
| C&N E-Commerce Ltd | Wholesale & retail | 2025 |
| C-Yang Herb Limited | Health & social care | 2018 |
| C.H.C. Properties Limited | Hospitality | 1983 |
| C3 Property Services Ltd | Real estate | 2025 |
| Cabragh Mushroom Composts Limited | Manufacturing | 2001 |
| Cabragh Trading Ltd | Construction | 2008 |
| CAE Solutions Limited | Manufacturing | 2025 |