| Andrew Perry Landscapes Ltd | Administrative & support | 2026 |
| Andrews Car Electrics Ltd | Wholesale & retail | 2014 |
| Andrews Farms Limited | Agriculture & fishing | 2026 |
| Androcles Ltd | Real estate | 2024 |
| Anglezarke Life Sciences Ltd | Professional & scientific | 2014 |
| Angn Properties Ltd | Real estate | 2024 |
| Animal Rehab NI Ltd | Professional & scientific | 2016 |
| Anita Acheson Ltd | Wholesale & retail | 2025 |
| ANN Popular Limited | Wholesale & retail | 2025 |
| Annabel Limited | Wholesale & retail | 2025 |
| Anooserve Ltd | Information & communication | 2016 |
| Anpeelen Limited | Wholesale & retail | 2025 |
| Ansiden Classic Ltd | Wholesale & retail | 2025 |
| Anvil Sound Ltd | Real estate | 2022 |
| Aotuinsights Creative Ltd | Wholesale & retail | 2024 |
| AOY Business Ltd | Wholesale & retail | 2024 |
| Apex Hive Limited | Wholesale & retail | 2023 |
| Apex Hospitality Ltd | Hospitality | 2024 |
| Apex Pharaoh Limited | Construction | 2005 |
| Apex Shilajit Ltd | Hospitality | 2025 |
| APK Communications Limited | Wholesale & retail | 2019 |
| Appin Lodge Investments Ltd | Real estate | 2026 |
| Applehot Products Limited | Wholesale & retail | 2025 |
| Applichat Limited | Professional & scientific | 2020 |
| APT Advisory Limited | Professional & scientific | 2021 |
| APT. Fabrics Ltd | Manufacturing | 2008 |
| Aqualla Brassware Ltd | Wholesale & retail | 2011 |
| Arachnid Limited | Wholesale & retail | 2025 |
| Aracya 818 Ltd | Wholesale & retail | 2025 |
| Archem (N.I.) Ltd | Manufacturing | 2003 |
| Archlona Joinery Ltd | Construction | 2026 |
| Arctic Cubes Ltd | Manufacturing | 2020 |
| ARD Cuan Care Homes Ltd | Health & social care | 2006 |
| Ardmillan Investments Limited | Real estate | 2019 |
| Ardmillan Trading Limited | Wholesale & retail | 2017 |
| Ardnalea House Apartments Limited | Households | 1998 |
| Ards Brewing Company Ltd | Manufacturing | 2011 |
| Ards Business Centre Ltd | Real estate | 1988 |
| Ards Development Bureau & Community Network | Health & social care | 1999 |
| Ards Fireplaces Limited | Wholesale & retail | 2010 |
| Ards Football Club, Limited | Arts & recreation | 1968 |
| Ards Fuels Ltd | Wholesale & retail | 2019 |
| Ards Motor Cycle Club Limited | Arts & recreation | 1950 |
| Ards Yoga & Wellness Rooms Ltd | Arts & recreation | 2021 |
| Ardza Ltd | Manufacturing | 2021 |
| Aris Zvaigzditis Limited | Wholesale & retail | 2025 |
| ARJ Homes Ltd | Real estate | 2026 |
| Arkford Ltd | Manufacturing | 2017 |
| Arsraukct Limited | Wholesale & retail | 2025 |
| Arthurs Brothers Island-A-Breen Limited | Agriculture & fishing | 2018 |
| Artificial Grass Company Limited | Extraterritorial | 2010 |
| Ashbourne Court Development Co. Limited | Households | 1985 |
| Ashdon Care Limited | Health & social care | 1993 |
| Ashleigh Cameron Ltd | Health & social care | 2025 |
| Assist Auto Group Limited | Wholesale & retail | 2015 |
| Assure Property Claims & Solutions Ltd | Water & waste | 2025 |
| Asylum Weightlifting Club Ltd. | Arts & recreation | 2019 |
| Athena Core Solutions Limited | Professional & scientific | 2025 |
| ATR Trading Co Ltd | Wholesale & retail | 1960 |
| Audley Construction Ltd | Construction | 2018 |
| Augmentafire Limited | Information & communication | 2026 |
| Auld House Inns Limited | Hospitality | 2015 |
| Aurent Consulting Limited | Professional & scientific | 2014 |
| Austin Rice Ltd | Wholesale & retail | 2025 |
| Autoedgesolutions Ltd | Information & communication | 2025 |
| Autrad Distribution Co. Limited | Extraterritorial | 1978 |
| Avalard Productions Ltd | Information & communication | 2022 |
| Avalon Guitars Limited | Manufacturing | 2024 |
| Avante Partners Ltd | Professional & scientific | 2018 |
| Avenir EMS Ltd | Professional & scientific | 2017 |
| AVG Global Ltd | Administrative & support | 2017 |
| Avisandum Ltd | Wholesale & retail | 2021 |
| Avocado Blue (NI) LLP | | 2014 |
| Avocado Orange Ltd | Construction | 2017 |
| Avonview Developments Ltd | Real estate | 2022 |
| AWE Semantics Limited | Information & communication | 2009 |
| Ayartm Limited | Wholesale & retail | 2017 |
| Ayre Environmental Consulting Ltd | Professional & scientific | 2018 |
| B M Autoexchange Ltd | Wholesale & retail | 2015 |
| B Ritchie Bricklaying and Building Contractor Limited | Construction | 2019 |
| B.I.G. Residential Ltd | Real estate | 2026 |
| BA Aero Ltd | Manufacturing | 2016 |
| Backspindle Games Limited | Manufacturing | 2010 |
| BAD BOY Vaping Ltd | Wholesale & retail | 2020 |
| Bailey LEA Management Company Limited | Households | 2025 |
| Bailies Development Management Company Limited | Extraterritorial | 2002 |
| Balfour Property Holdings Limited | Real estate | 2026 |
| Balloo Inns Limited | Hospitality | 2008 |
| Ballyalton Limited | Professional & scientific | 2017 |
| Ballyblack Hall Management Company | Real estate | 2012 |
| Ballybunden Ltd | Professional & scientific | 2016 |
| Ballycullen Ltd | Construction | 2013 |
| Ballygowan Environmental Ltd | Professional & scientific | 2023 |
| Ballygrangee Developments Ltd | Real estate | 2025 |
| Ballyhalbert Gospel Hall | Other services | 2014 |
| Ballykeel Enterprise Limited | Real estate | 2021 |
| Ballyknockan Management Company Limited | Households | 2020 |
| Ballymullan Trading Limited | Wholesale & retail | 2011 |
| Ballyrush Properties Ltd | Financial services | 2026 |
| Ballyrusley Stables Ltd | Arts & recreation | 2025 |