| Belfast Print Ltd | Manufacturing | 2020 |
| Belfast Print Online Ltd | Manufacturing | 2019 |
| Belfast Print Workshop | Arts & recreation | 1997 |
| Belfast Private Tours Limited | Administrative & support | 2016 |
| Belfast Properties Ltd | | 2004 |
| Belfast Property Developments Ltd | Real estate | 2024 |
| Belfast Property Group Ltd | Real estate | 2022 |
| Belfast Property Holdings Limited | Real estate | 2026 |
| Belfast Property Limited | Construction | 2026 |
| Belfast Property Pads Ltd | Real estate | 2021 |
| Belfast Property Solutions (NI) Limited | Real estate | 2013 |
| Belfast Psychology Services Ltd | Health & social care | 2022 |
| Belfast PUB Co. Ltd | Hospitality | 2019 |
| Belfast PUB Crawl Ltd | Administrative & support | 2020 |
| Belfast Recovery Service Ltd | Wholesale & retail | 2022 |
| Belfast Rented Homes Ltd | Real estate | 2014 |
| Belfast Repair Centre Limited | Other services | 2019 |
| Belfast Respiratory Clinic Limited | Health & social care | 2024 |
| Belfast Road Properties Ltd | Construction | 2020 |
| Belfast Roller Derby Limited | Arts & recreation | 2014 |
| Belfast Roofing Ltd | Construction | 2019 |
| Belfast Rooftops Ltd | Arts & recreation | 2019 |
| Belfast Rooms Limited | Real estate | 2025 |
| Belfast Ropework Company Limited | Real estate | 2021 |
| Belfast Rowing Club CIC | Arts & recreation | 2025 |
| Belfast Sales Academy Limited | Real estate | 2013 |
| Belfast Salt Company Ltd | Wholesale & retail | 2014 |
| Belfast Samaritans | Other services | 2017 |
| Belfast School of Performing Arts Ltd. | Education | 2018 |
| Belfast School of Theology Limited | Education | 2004 |
| Belfast Self Storage Limited | Wholesale & retail | 1996 |
| Belfast Service Centre Limited | Wholesale & retail | 2014 |
| Belfast Service Limited | Professional & scientific | 2023 |
| Belfast Sight Seeing Ltd | Administrative & support | 2025 |
| Belfast South Network Company | Administrative & support | 2010 |
| Belfast Specsavers Hearcare Limited | Wholesale & retail | 2006 |
| Belfast Specsavers Limited | Wholesale & retail | 1992 |
| Belfast Sport and Health Clinic Ltd | Health & social care | 2020 |
| Belfast Sports and Spinal Ltd | Health & social care | 2014 |
| Belfast Storage Limited | Transport & logistics | 2017 |
| Belfast Store Ltd | Wholesale & retail | 2025 |
| Belfast Street Pastors | Health & social care | 2015 |
| Belfast Student Accommodation Limited | Real estate | 2012 |
| Belfast Student Property Investment Company Limited | Real estate | 2012 |
| Belfast Surgical Services Limited | Health & social care | 2020 |
| Belfast Swifts FC C.I.C. | Arts & recreation | 2017 |
| Belfast Taco Cartel II Limited | Hospitality | 2020 |
| Belfast Taco Cartel Limited | Hospitality | 2018 |
| Belfast Taxation Services Limited | Professional & scientific | 1997 |
| Belfast Taxi and Coach C.I.C. | Transport & logistics | 2012 |
| Belfast Taxi Tours Ltd | Transport & logistics | 2025 |
| Belfast Taxis C.I.C | Transport & logistics | 2009 |
| Belfast Tech Hub Limited | Wholesale & retail | 2025 |
| Belfast Tech Services Ltd | Information & communication | 2021 |
| Belfast Technology Consulting Limited | Information & communication | 2023 |
| Belfast Theatrical Linens Limited | Wholesale & retail | 2006 |
| Belfast Tile & Stone Contracts Limited | Construction | 2019 |
| Belfast Tile Company Limited - the | | 1994 |
| Belfast Tiles & Bathrooms Ltd | Wholesale & retail | 2025 |
| Belfast Tiles and Bathroom Centre Ltd | Wholesale & retail | 2005 |
| Belfast Titanic Hotel Limited | Hospitality | 2015 |
| Belfast Tool Library Ltd | Administrative & support | 2019 |
| Belfast Tours Ltd | Administrative & support | 2010 |
| Belfast Towage Limited | Transport & logistics | 2013 |
| Belfast Trans Resource Centre Limited | Health & social care | 2024 |
| Belfast Transport Solutions Limited | Real estate | 2019 |
| Belfast Tully Property Limited | Real estate | 2020 |
| Belfast Turnover Co Ltd | Administrative & support | 2026 |
| Belfast Underground Limited | Wholesale & retail | 2015 |
| Belfast Urban Developments Limited | Construction | 2016 |
| Belfast Urban Sports Ltd | Health & social care | 2007 |
| Belfast Vapes Limited | Wholesale & retail | 2026 |
| Belfast Vehicle Hire Ltd | Administrative & support | 2022 |
| Belfast Veterinary Care Ltd | Professional & scientific | 2025 |
| Belfast Visionplus Limited | Wholesale & retail | 1993 |
| Belfast Visitor and Convention Bureau Limited | Wholesale & retail | 1998 |
| Belfast Waterfront and Ulster Hall Limited | Arts & recreation | 2016 |
| Belfast Ymca Limited | Other services | 1960 |
| Belfastit Ltd | Manufacturing | 2021 |
| Belfastrentals Limited | Real estate | 2023 |
| Belfcard Limited | | 2004 |
| Belfore Solutions Ltd | Wholesale & retail | 2021 |
| Belforge Ltd | Real estate | 2022 |
| Belfry Properties and Plant Limited | Real estate | 2003 |
| Belgard Overseas Projects LP | | 2018 |
| Belgian Beer Belfast Limited | Wholesale & retail | 2025 |
| Belgrave Contract Management Limited | Administrative & support | 2012 |
| Belgrave Court Limited | Households | 1999 |
| Belial Limited | Wholesale & retail | 2025 |
| Believel Ltd | Wholesale & retail | 2025 |
| Bell Gray House (Ireland) Ltd | Health & social care | 2020 |
| Bell Kite Ltd | Professional & scientific | 2019 |
| Bell Recruitment Services Limited | Administrative & support | 2001 |
| Bell Towers Management Company (Phase 2) Limited | Households | 2004 |
| Bell Towers Management Limited - the | Households | 2002 |
| Bell Windows (NI) Limited | Construction | 2013 |
| Bella Group Ltd | Hospitality | 2019 |
| Bellablue Competitions Ltd | Arts & recreation | 2024 |
| Belladonna Beauty Ltd | Other services | 2025 |
| Belle Ting Limited | Wholesale & retail | 2023 |