| 10 Brookhill Avenue Management Company Limited | Hospitality | 2008 |
| 131 Fitness & Gym Ltd | Arts & recreation | 2025 |
| 1816 Property Group Ltd | Real estate | 2026 |
| 240VOLTS Software Ltd | Information & communication | 2020 |
| 2ND Nature Dental Design Ltd. | Manufacturing | 2015 |
| 2SIXTY Consulting Limited | Information & communication | 2024 |
| 34 Wellington Park Management Company Ltd | Households | 2017 |
| 365 Car and Commercial Sales Ltd | Wholesale & retail | 2017 |
| 4CADA Ltd | Hospitality | 2019 |
| 4T&P Ltd | Real estate | 2024 |
| 5 Amour Ltd | Wholesale & retail | 2022 |
| 5 Star Vehicle Valeting Services Ltd | Extraterritorial | 2022 |
| 53 Church Road Apartment Management Company Limited | Real estate | 2005 |
| 5XTECHNOLOGIES Ltd | Professional & scientific | 2016 |
| 6 & 6A Rosetta Park Apartments Management Company Limited | Real estate | 2007 |
| 699 Antrim Road Management Company Limited | Real estate | 2014 |
| 77 Retail Ballybeen Holdings Limited | Wholesale & retail | 2022 |
| 77 Retail Ballybeen Limited | Wholesale & retail | 2022 |
| 88 Retail Holdings Limited | Wholesale & retail | 2022 |
| 88 Retail Limited | Wholesale & retail | 2015 |
| 95 North Ltd | Real estate | 2025 |
| A Moment in Time Ltd | Manufacturing | 2021 |
| A Quiet Life Studio Ltd | Wholesale & retail | 2025 |
| A W Electrics Ltd. | Construction | 2015 |
| A&M Johnston Ltd | Wholesale & retail | 2025 |
| A.B.B.E.Y. Sure Start | Education | 2001 |
| A.T. (Ireland) Limited | Construction | 2000 |
| A2B Skip Hire Ltd | Water & waste | 2019 |
| A2Z Medic Ltd | Health & social care | 2019 |
| Abacus Renovation & Maintenance Ltd | Construction | 2025 |
| Abbey Autos (Glengormley) Limited | Wholesale & retail | 2011 |
| Abbey Car Care (N.I.) Ltd | Wholesale & retail | 2025 |
| Abbey Centre Specsavers Limited | Wholesale & retail | 2003 |
| Abbey Centre Visionplus Limited | Wholesale & retail | 2003 |
| Abbey Coach Travel Ltd | Transport & logistics | 2026 |
| Abbey Craft Pool & Snooker Ltd | Manufacturing | 2024 |
| Abbey Exhausts Limited | Wholesale & retail | 2019 |
| Abbey Kitchens & Bathrooms Limited | Manufacturing | 1995 |
| Abbey Life Church Ltd | Other services | 2021 |
| Abbey Technical Services Ltd | Information & communication | 2019 |
| Abbey Vent Ltd | Construction | 2026 |
| Abbey-Crete Limited | Manufacturing | 1984 |
| AC Components Limited | Wholesale & retail | 2014 |
| Acbm Limited | Wholesale & retail | 2022 |
| Account Management Solution Ltd | Wholesale & retail | 2025 |
| Ace Design Belfast Ltd | Professional & scientific | 2023 |
| Ace Property Contracts Ltd | Real estate | 2021 |
| Acksen Ltd | Manufacturing | 1986 |
| Acni Consultancy Limited | Professional & scientific | 2022 |
| Acni Property Management Ltd | Real estate | 2022 |
| Acorns North Limited | Education | 2010 |
| AD Marketing Precision Limited | Professional & scientific | 2025 |
| AD Plastic Surgery Limited | Health & social care | 2020 |
| ADAPT365 Ltd | Professional & scientific | 2019 |
| Adaptni CIC | Administrative & support | 2022 |
| Admor Business Solutions Limited | Professional & scientific | 2007 |
| Adsora Homes Ltd | Real estate | 2024 |
| Advanced Freight Solutions NI Ltd | Transport & logistics | 2022 |
| Advanced NI Scaffolding Ltd | Construction | 2011 |
| Advanced Timber Craft (NI) Ltd | Construction | 2002 |
| Aeeconsultancy Ltd | Professional & scientific | 2025 |
| Aeera Catering Group Ltd | Hospitality | 2026 |
| AG Group (2026) Ltd | Hospitality | 2026 |
| Agri Caretrade Ltd | Manufacturing | 2025 |
| AH Global Consulting Ltd | Professional & scientific | 2020 |
| Ahad Retail Ltd | Wholesale & retail | 2024 |
| AI Services (Northern Ireland) Limited | Agriculture & fishing | 1988 |
| Aionis Digital Limited | Information & communication | 2025 |
| Airframe Antennas Ltd | Manufacturing | 2026 |
| Airport Technical Service Limited | Manufacturing | 2012 |
| AIS Engineering Consulting Ltd | Professional & scientific | 2020 |
| AJ Properties Belfast Ltd | Real estate | 2019 |
| Ajbsm Ltd | Hospitality | 2024 |
| Alan Graham Property Limited | Other services | 2021 |
| ALB Autos 2025 Ltd | Wholesale & retail | 2025 |
| Aldo's UN Limited | Professional & scientific | 2025 |
| Aletes Consulting Ltd | Professional & scientific | 2020 |
| ALI Crystal UK Limited | Financial services | 2025 |
| ALI Pleiades UK Limited | Manufacturing | 2025 |
| Allen Integrated Solutions Ltd | Professional & scientific | 2012 |
| Allister Moore Welding & Engineering Supplies Ltd | Wholesale & retail | 2001 |
| Almara Properties Limited | Real estate | 2001 |
| Alpha Resource Management Ltd | Energy | 2006 |
| Alternative Healing Ltd | Manufacturing | 2020 |
| Altius Technologies Limited | Information & communication | 2018 |
| ALW Property Limited | Financial services | 2016 |
| AM Autowash Ltd | Administrative & support | 2018 |
| AM BID Consulting Limited | Administrative & support | 2017 |
| AM Nolan Ltd | Wholesale & retail | 2024 |
| Amarjeet Joinery Cottage Ltd | Construction | 2025 |
| Amazonian Fit Limited | Arts & recreation | 2022 |
| AMP UK Members Limited | Financial services | 2012 |
| Ampersand Engineering Limited | Information & communication | 2016 |
| Ampl Design Ltd | Professional & scientific | 2021 |
| Ampuk Holdings Ltd | Professional & scientific | 2015 |
| Ampuk Property Services Ltd | Real estate | 2015 |
| Andrew Stewart Web & Graphic Design Ltd | Information & communication | 2017 |
| Andrews Opticians Ltd | Health & social care | 2013 |
| Anna's Grove Management Company Limited | Households | 2002 |
| Annie Travel Ltd | Administrative & support | 2021 |