| Belfast Educational Services (Down & Connor) Holdings Limited | Administrative & support | 2008 |
| Belfast Educational Services (Down & Connor) Limited | Administrative & support | 2008 |
| Belfast Educational Services (Downpatrick) Holdings Limited | Administrative & support | 2008 |
| Belfast Educational Services (Downpatrick) Limited | Administrative & support | 2008 |
| Belfast Educational Services (Dungannon) Holdings Ltd | Administrative & support | 2002 |
| Belfast Educational Services (Dungannon) Limited | Administrative & support | 2003 |
| Belfast Educational Services (Holdings) Limited | Administrative & support | 2000 |
| Belfast Educational Services (Omagh) Holdings Limited | Administrative & support | 2002 |
| Belfast Educational Services (Omagh) Limited | Administrative & support | 2002 |
| Belfast Educational Services (Strabane) Holdings Limited | Administrative & support | 2006 |
| Belfast Educational Services (Strabane) Limited | Administrative & support | 2006 |
| Belfast Educational Services Limited | Administrative & support | 2000 |
| Belfast Electrical Ltd | Construction | 2026 |
| Belfast Electrical Supplies Ltd | Wholesale & retail | 2006 |
| Belfast Endo Ltd | Health & social care | 2023 |
| Belfast Energy Storage Company Limited | Energy | 2019 |
| Belfast Equipment Sales & Hire Ltd | Wholesale & retail | 2025 |
| Belfast Estate Agents Ltd | Real estate | 2025 |
| Belfast Exposed Photography | Arts & recreation | 2001 |
| Belfast Fashion Designs Limited | Manufacturing | 2018 |
| Belfast Fast Fit Ltd | Professional & scientific | 2024 |
| Belfast Fast Forward Ltd | Wholesale & retail | 2019 |
| Belfast Fertility Limited | Health & social care | 2016 |
| Belfast Festival | Education | 2015 |
| Belfast Film Festival Ltd | Arts & recreation | 1997 |
| Belfast Filmmaking Club CIC | Health & social care | 2025 |
| Belfast Fleet Sales Limited | Wholesale & retail | 2025 |
| Belfast FM Limited | Information & communication | 2012 |
| Belfast Food Co Ltd | Hospitality | 2026 |
| Belfast Foods (2016) Ltd | Hospitality | 2016 |
| Belfast Garden Rooms Ltd | Construction | 2023 |
| Belfast Garden Services Limited | Administrative & support | 2025 |
| Belfast GAS Ltd | Construction | 2026 |
| Belfast GAS Transmission Limited | Energy | 1992 |
| Belfast Gasworks Management Co. Ltd. | Real estate | 2017 |
| Belfast Giants Ltd | | 2000 |
| Belfast Girl's Club Union-The | Arts & recreation | 1946 |
| Belfast Global Ltd | Wholesale & retail | 2025 |
| Belfast Good Chicken Ltd | Hospitality | 2025 |
| Belfast Hammers LLP | | 2024 |
| Belfast Harbour Film Studios Limited | Information & communication | 2018 |
| Belfast Harbour Pension Fund Limited | Financial services | 1964 |
| Belfast Harbour Properties Limited | Real estate | 2021 |
| Belfast Healthcare Limited | Health & social care | 2026 |
| Belfast Healthcare Services Ltd | Health & social care | 2026 |
| Belfast HEN Party Ltd | Administrative & support | 2018 |
| Belfast Hills Partnership Trust | Professional & scientific | 2004 |
| Belfast Holiday Rentals Limited | Hospitality | 2016 |
| Belfast Homeless Services | Health & social care | 2019 |
| Belfast Hospitality Ltd | Hospitality | 2011 |
| Belfast Hotel Developments Limited | Extraterritorial | 2012 |
| Belfast Hotel Group Ltd | Hospitality | 2016 |
| Belfast Insulation Co. Limited | Construction | 1998 |
| Belfast Intercultural Romanian Community CIC | Information & communication | 2021 |
| Belfast Interface Project | Other services | 2007 |
| Belfast International Language Academy Ltd. | Education | 2015 |
| Belfast International Watersports Limited | Arts & recreation | 2017 |
| Belfast Invictus Restaurants Limited | Hospitality | 2018 |
| Belfast Iqraa School | Education | 2017 |
| Belfast Joint-Holdings Limited | Real estate | 2022 |
| Belfast Limousine Company Ltd | Transport & logistics | 2018 |
| Belfast Lodges Ltd | Hospitality | 2023 |
| Belfast Lodgings Ltd | Hospitality | 2013 |
| Belfast Loft Company Ltd | Construction | 2021 |
| Belfast Makerspace Ltd | Arts & recreation | 2024 |
| Belfast Marble Limited | Construction | 2012 |
| Belfast Media Festival Ltd | Information & communication | 2023 |
| Belfast Media Group Limited | Information & communication | 2003 |
| Belfast Medico Europe Limited | Professional & scientific | 2023 |
| Belfast Meet & Greet Ltd | Administrative & support | 2022 |
| Belfast Migraine Clinic Ltd | Health & social care | 2026 |
| Belfast Mobile Cafe Ltd | Wholesale & retail | 2021 |
| Belfast Murals Taxi Tours Ltd | Administrative & support | 2024 |
| Belfast Music Society Limited | Arts & recreation | 2016 |
| Belfast Nails and Spa Ltd | Other services | 2021 |
| Belfast Nails Ltd | Other services | 2021 |
| Belfast Natural GAS Limited | Extraterritorial | 1997 |
| Belfast News & Features Limited | Information & communication | 2016 |
| Belfast One BID Limited | Other services | 2016 |
| Belfast Open Kitchen (N.I.) Limited | Hospitality | 2016 |
| Belfast Operatic Company | Arts & recreation | 2020 |
| Belfast Orangefest | Education | 2007 |
| Belfast Orthodontic Centre Ltd | Health & social care | 2023 |
| Belfast Orthopaedic Specialist Group Limited | Health & social care | 2015 |
| Belfast P.A.T. Testing Limited | Professional & scientific | 2003 |
| Belfast Pads Limited | Hospitality | 2018 |
| Belfast Paints Limited | Wholesale & retail | 2019 |
| Belfast Park Centre Specsavers Limited | Wholesale & retail | 2011 |
| Belfast Pedal Tour Ltd | Administrative & support | 2014 |
| Belfast Pest Control Limited | Administrative & support | 2024 |
| Belfast Pilates & Physiotherapy Limited | Other services | 2021 |
| Belfast Pizza Blogger Ltd | Hospitality | 2022 |
| Belfast Playwrights CIC | Arts & recreation | 2026 |
| Belfast Port Security Authority Limited | Transport & logistics | 2013 |
| Belfast Port Services Limited | Transport & logistics | 1993 |
| Belfast Poverty Truth Commission CIC | Professional & scientific | 2025 |
| Belfast Powerflushing Ltd | Construction | 2023 |
| Belfast Premier Residential Rentals Limited | Real estate | 2022 |
| Belfast Prestige Restaurants Limited | Hospitality | 2018 |
| Belfast Pride Ltd | Arts & recreation | 2021 |