| Arfon Timber Frames Ltd | Construction | 2023 |
| Argarth Collective Ltd | Information & communication | 2025 |
| Arioch Events Ltd | Administrative & support | 2023 |
| ARK GI Limited | Health & social care | 2024 |
| Arkerom Limited | Professional & scientific | 2025 |
| Armstrong Auctions Limited | Other services | 2022 |
| Arnott Water Services Limited | Professional & scientific | 2024 |
| Arredare Limited | Wholesale & retail | 2011 |
| Arrow Taxi Bangor Ltd | Transport & logistics | 2026 |
| Arslan HM Ltd | Hospitality | 2025 |
| Asad Crop Ltd | Wholesale & retail | 2025 |
| Ascot House Limited | Extraterritorial | 1985 |
| Asha Tandoori (Bangor) Limited | Hospitality | 2022 |
| Ashruby Limited | Real estate | 2025 |
| Asking Solutions Limited | Construction | 2021 |
| Asni Client Ltd. | Professional & scientific | 2020 |
| Asni Trading Ltd | Professional & scientific | 2025 |
| Aspire Create Limited | Construction | 2014 |
| Assetiq Ltd | Professional & scientific | 2009 |
| Assistkidz Ltd | Health & social care | 2019 |
| Assured Pro Roofing Ltd | Construction | 2026 |
| Astala Lodge (Bangor) Ltd | Real estate | 2019 |
| Astbury Heating Limited | Construction | 2005 |
| Aston Academy Limited | Education | 2015 |
| Astoria Kindergarten and Wraparound Ltd | Health & social care | 2025 |
| Astoria Kindergarten Limited | Health & social care | 2019 |
| Atchison Designs Ltd | Manufacturing | 2020 |
| Atlas Digi Limited | Administrative & support | 2025 |
| Atrium Living Ltd | Real estate | 2023 |
| Auburn Beauty Limited | Other services | 2024 |
| Aufiru Ltd | Hospitality | 2025 |
| Auntie Anne's Bangor Ltd | Wholesale & retail | 2019 |
| Auntie Anne's Glasgow Ltd | Hospitality | 2019 |
| Aurora River Ltd | Financial services | 2025 |
| Autodash-Pro Ltd | Information & communication | 2026 |
| Autovolt Solutions Ltd | Wholesale & retail | 2025 |
| Avalon 94 Limited | Real estate | 2017 |
| Avalon Buyer Limited | Financial services | 2025 |
| Avalon Midco Limited | Financial services | 2025 |
| Avant-Garde Learning & Development Ltd | Education | 2023 |
| Averont Limited | Administrative & support | 2026 |
| Aveta Limited | Information & communication | 2007 |
| Avio Labs Ltd | Information & communication | 2021 |
| Avoca House Management Company Limited | Extraterritorial | 1998 |
| Avocet Trading Limited | Wholesale & retail | 2017 |
| Awesome Earthmovers Ltd | Information & communication | 2021 |
| Ayat Fatima Ltd | Wholesale & retail | 2025 |
| Ayeland Audio Ltd | Information & communication | 2020 |
| Ayosinmi Consultancy Ltd | Professional & scientific | 2026 |
| AZT Properties Limited | Professional & scientific | 2015 |
| Azul Property Limited | Real estate | 2021 |
| B & M Davies (Bangor) Limited | Transport & logistics | 2018 |
| B&J Car Valeting Ltd | Administrative & support | 2023 |
| B&J Service Ltd | Information & communication | 2011 |
| B.J. Marine Limited | Wholesale & retail | 1988 |
| Bacchanalwood Ltd | Hospitality | 2021 |
| Bacmann Water Ltd | Professional & scientific | 2006 |
| Bacon Software Limited | Information & communication | 2015 |
| Bagel Bros Ltd | Hospitality | 2025 |
| Bailey Lane Student Limited | Construction | 2017 |
| Baillie Barclay Limited | Real estate | 2021 |
| Baillies of Bangor Limited | Wholesale & retail | 2012 |
| Bakari Bakery Limited | Manufacturing | 2022 |
| Baldybeardy Ltd. | Wholesale & retail | 2015 |
| Baleap | Other services | 2010 |
| Balloo Furnishings Limited | | 1989 |
| Balloo House Care Ltd | Health & social care | 2019 |
| Balloo Skip Hire Ltd | Water & waste | 2016 |
| Balloo Trade Frames Ltd | Manufacturing | 2011 |
| Ballygrainey Manor Limited | Real estate | 2020 |
| Ballyholme Esplanade Management Company Limited | Households | 2006 |
| Ballyholme Ltd | Administrative & support | 2010 |
| Ballyholme Meats Limited | Hospitality | 2018 |
| Ballyholme Mews Management Company Limited | Households | 2024 |
| Ballyholme View Limited | Extraterritorial | 2003 |
| Ballynashee Investments Ltd | Financial services | 2025 |
| Ballysillan Health Care Ltd | Wholesale & retail | 2022 |
| Ballywilliam Catering Ltd | Hospitality | 2020 |
| Balmoral Square Apartment Management Limited | Extraterritorial | 2023 |
| Bamberg Holding Co Ltd | Agriculture & fishing | 2023 |
| Bamstick Ltd | Information & communication | 2021 |
| Bangor 1 Ltd | Hospitality | 2025 |
| Bangor Abbey Preschool Ltd | Education | 2017 |
| Bangor Affordable Cars Limited | Wholesale & retail | 2021 |
| Bangor Alternatives Limited | Other services | 2010 |
| Bangor and Caernarfon Business Against Crime CYF | Administrative & support | 2006 |
| Bangor and North Down Samaritans | Other services | 2017 |
| Bangor Angling Club Limited | Agriculture & fishing | 2018 |
| Bangor Auto Service Limited | Wholesale & retail | 2025 |
| Bangor Auto Village Ltd | Wholesale & retail | 2014 |
| Bangor AYE Ltd | Other services | 2025 |
| Bangor Business Centre Limited | Real estate | 2022 |
| Bangor Business Improvement District Limited | Other services | 2024 |
| Bangor Business Solutions Ltd | Extraterritorial | 2008 |
| Bangor Cabs Ltd | Transport & logistics | 2012 |
| Bangor Cash Register Company Limited | Information & communication | 2003 |
| Bangor Chamber of Commerce Limited | Other services | 1999 |
| Bangor City Chamber of Trade CIC | Other services | 2025 |
| Bangor City Football Club Limited | Arts & recreation | 2025 |
| Bangor Curry Ltd | Hospitality | 2024 |