| Beltoy Associates Limited | Financial services | 2005 |
| BEN Investments Limited | Real estate | 2018 |
| Benfry Holdings Limited | Professional & scientific | 2020 |
| Benmore House Enterprises Limited | Hospitality | 2024 |
| Berhael Trading Limited | Manufacturing | 2017 |
| Berrysayer Properties Ltd | Real estate | 2022 |
| Bespoke Woodworks and Cabinetry Ltd | Manufacturing | 2024 |
| Best Choice Door Fitting Ltd | Construction | 2022 |
| Best Choice Garage Doors Ltd | Manufacturing | 2010 |
| BH Automotive Ltd | Wholesale & retail | 2024 |
| BH Preparation Ltd | Wholesale & retail | 2019 |
| Big Buffalo Ltd | Wholesale & retail | 2024 |
| BIM Coffee Ltd | Professional & scientific | 2025 |
| BIM Recruiter Ltd | Administrative & support | 2022 |
| Binghuhu Limited | Wholesale & retail | 2024 |
| Biotech Energy Systems Ltd | Wholesale & retail | 2016 |
| BJT & SON Ltd | Wholesale & retail | 2015 |
| BJT Plant Hire Limited | Administrative & support | 2008 |
| Black Developments Limited | Real estate | 2006 |
| Black Pine Iron Craft Studio Ltd | Manufacturing | 2026 |
| Black Retail Limited | Extraterritorial | 2009 |
| Black Shuck Roofing Ltd | Construction | 2025 |
| Blackthorn & Rose Ltd | Wholesale & retail | 2025 |
| Blackwatch Industries Ltd | Extraterritorial | 2000 |
| Blackwater Private Clinic Enniskillen Ltd | Health & social care | 2026 |
| Blakely Mccartney, Limited | Hospitality | 1954 |
| Blakes Fine Wine Ltd | Wholesale & retail | 2007 |
| Blaney Power Limited | Energy | 2017 |
| Blind Spot Mushies Ltd | Agriculture & fishing | 2026 |
| Blue Wave Boat and Marine Ltd | Manufacturing | 2023 |
| Blue Wren Consulting Ltd | Professional & scientific | 2021 |
| Bluebell Glade Management Company Limited | Households | 2017 |
| Bluegreenyonder Ltd | Information & communication | 2002 |
| Bluestack Civils Limited | Construction | 2019 |
| BM Commercial Properties Limited | Real estate | 2014 |
| Bmac Electrical Services Ltd | Construction | 2025 |
| Bmcg PG Limited | Households | 2025 |
| BMG Hardware (Fermanagh) Limited | Wholesale & retail | 2017 |
| BML Focus Limited | Real estate | 2017 |
| BOA Island Properties Ltd | Construction | 2013 |
| Bogue Legal Ltd | Professional & scientific | 2021 |
| Bonar Plant Hire Limited | Transport & logistics | 2010 |
| Bopworx Limited | Manufacturing | 2011 |
| Border Fuels Ltd | Wholesale & retail | 2024 |
| Botheen MEN Retail NI Ltd | Wholesale & retail | 2018 |
| Bounce About Fermanagh Ltd | Administrative & support | 2023 |
| Boxflow Limited | Arts & recreation | 2025 |
| BPN Group Ltd | Wholesale & retail | 2025 |
| Bradley Surgery Ltd | Professional & scientific | 2015 |
| Brady Assessors Limited | Professional & scientific | 2023 |
| Bradys Bike Spares Ltd | Wholesale & retail | 2019 |
| Braeside Car Sales Limited | Wholesale & retail | 2016 |
| Bragan Trading Services Ltd | Wholesale & retail | 2009 |
| Brannish Poultry Ltd | Agriculture & fishing | 2022 |
| Bredagh Medical Services Ltd | Health & social care | 2024 |
| Breen Wind Energy (N.I.) Ltd | Real estate | 2018 |
| Brenda Bannon Health & Performance Coaching Ltd | Health & social care | 2024 |
| Breslin Tractors Ltd | Wholesale & retail | 2011 |
| Brewit Solutions Limited | Information & communication | 2013 |
| Brian Coalter Transport Limited | Transport & logistics | 2016 |
| Bridge Gymnastics Club CIC | Arts & recreation | 2025 |
| Bridge Gymnastics Ltd | Arts & recreation | 2020 |
| Brilaur Catering Ltd | Hospitality | 2024 |
| Brimark Properties Limited | Construction | 2026 |
| Briskin Properties Limited | Real estate | 2007 |
| Broadview Properties Limited | Hospitality | 2005 |
| Brodar Holdings Limited | Financial services | 2023 |
| Brooks Alley Developments Ltd | Construction | 2025 |
| BS Agricultural Contracting Limited | Agriculture & fishing | 2015 |
| BSC Plant Ltd | Wholesale & retail | 2020 |
| BSL Vehicle Servicing Limited | Wholesale & retail | 2025 |
| Buchram Management Limited | Professional & scientific | 2021 |
| Building and Compliance Services Ltd | Construction | 2023 |
| Bullough Trading Solutions Limited | Wholesale & retail | 2017 |
| Bunlougher Wind Limited | Energy | 2013 |
| Buns 2U Limited | Hospitality | 2017 |
| Burgo Brands Limited | Hospitality | 2026 |
| Burleigh Holdings Limited | Wholesale & retail | 2016 |
| Burnoutbliss Ltd | Manufacturing | 2025 |
| Bush Hospitality Ltd | Hospitality | 2014 |
| Bush Properties Limited | Real estate | 1999 |
| BV Estates Limited | Real estate | 2015 |
| Byeways Developments Limited | Real estate | 2017 |
| C & M Cold Stores (Northern Ireland) Limited | Transport & logistics | 1999 |
| C and V Loane Limited | Agriculture & fishing | 2004 |
| C J Maguire & Company Limited | Professional & scientific | 2012 |
| C Kane Building Solutions (UK) Limited | Construction | 2019 |
| C Kelly Plumbing & Heating Ltd | Construction | 2020 |
| C Kennedy Holdings Ltd | Wholesale & retail | 2024 |
| C O'Neill Construction Limited | Construction | 2024 |
| C.M.R. Construction Ltd | Construction | 2005 |
| C1ASS Fibre Ltd | Construction | 2023 |
| C2 Auto Sales Ltd | Wholesale & retail | 2026 |
| C@E Bricklaying Ltd | Construction | 2025 |
| Ca&H Consulting Ltd | Hospitality | 2021 |
| Cadco (NI) Limited | Wholesale & retail | 2010 |
| Cafe Nico Bellanaleck Ltd | Hospitality | 2024 |
| CAG Compliance Ltd | Administrative & support | 2023 |
| Cairn Investments Limited | Real estate | 2003 |
| California Camper Adventures Limited | Extraterritorial | 2022 |