| 14 North Engineering Limited | Professional & scientific | 2026 |
| 191 Ltd | Wholesale & retail | 2023 |
| 208 Investments Limited | Financial services | 2023 |
| 3 Construction Limited | Construction | 2024 |
| 3050 Ltd | Wholesale & retail | 2023 |
| 4EVER Cheaper Limited | Wholesale & retail | 2023 |
| 4MEN'S Ltd | Other services | 2023 |
| A & H (N.I.) Limited | Other services | 2021 |
| A C Meats Ltd | Wholesale & retail | 2015 |
| A Safe Space to BE ME Ltd | Other services | 2020 |
| A Short Logistics Solutions Ltd | Professional & scientific | 2020 |
| A Wolfenden Properties Ltd | Real estate | 2025 |
| A&R Nagappa Estates Limited | Real estate | 2022 |
| A1 Advisory Limited | Professional & scientific | 2026 |
| Aaron Lewis Engineering Services Ltd | Construction | 2023 |
| Aarondale Construction Limited | Construction | 2018 |
| Abcworks Ltd | Wholesale & retail | 2025 |
| Ace Executive Limited | Transport & logistics | 2022 |
| ACF Security Ltd | Administrative & support | 2022 |
| ACG Transport Limited | Transport & logistics | 2026 |
| Acsr Limited | Wholesale & retail | 2010 |
| Actal Corporate Ltd | Wholesale & retail | 2012 |
| AD Cortez Limited | Manufacturing | 2024 |
| Adco Property Investments Ltd | Real estate | 2015 |
| Advance Machinery Installation Ltd | Manufacturing | 2010 |
| Aesthetics Events and Promotions Ltd | Professional & scientific | 2022 |
| Afco Electrical Wholesale Limited | Wholesale & retail | 2022 |
| Afro Center Cosmetics Ltd | Other services | 2025 |
| AG Takeaway (2026) Ltd | Hospitality | 2026 |
| Aghaboy Aquaculture Limited | Extraterritorial | 2012 |
| AI Metaskills Limited | Information & communication | 2024 |
| AIM Careers Limited | Hospitality | 2023 |
| Aircorp Aviation Limited | Transport & logistics | 2023 |
| AJP Housing Limited | Real estate | 2022 |
| AJT Real Estate Limited | Real estate | 2026 |
| Akadaek Healthcare Ltd | Health & social care | 2021 |
| Alan Jones Architects Limited | Professional & scientific | 2002 |
| Alexander Tractors Ltd | Wholesale & retail | 2026 |
| ALI Rose Events Limited | Administrative & support | 2022 |
| Align Office Solutions Ltd | Wholesale & retail | 2026 |
| Aliz (4) Antrim Ltd | Hospitality | 2023 |
| ALL AB Limited | Construction | 2025 |
| ALL Clear Cleaning Service Ltd | Administrative & support | 2025 |
| ALL Stars Afterschool Club Ltd | Health & social care | 2022 |
| Allergy Northern Ireland Ltd | Extraterritorial | 2021 |
| Almak GEN Services Ltd | Health & social care | 2024 |
| Alpinebeat Unlimited | Financial services | 2020 |
| Alti Holdings Ltd | Financial services | 2026 |
| Altivara Ltd | Real estate | 2026 |
| Alutrade (NI) Limited | Manufacturing | 2015 |
| Amasu Ltd | Wholesale & retail | 2021 |
| Ambar Fire & Security Systems Ltd | Construction | 2025 |
| Amen Footwear Ltd | Wholesale & retail | 2016 |
| Amigos (NI) Ltd | Real estate | 2014 |
| AMIGOS2 NI Limited | Real estate | 2021 |
| AMIGOS3 N.I. Limited | Real estate | 2023 |
| Amour Beauty & Wellbeing Ltd | Other services | 2018 |
| AN Absolute Gift Ltd | Wholesale & retail | 2023 |
| Anaplastology Ireland Ltd | Professional & scientific | 2007 |
| Anchor Fixings Ltd | Wholesale & retail | 2012 |
| Andover One Ltd | Construction | 2002 |
| Andu D Ltd | Information & communication | 2023 |
| Anita's Health & Beauty Clinic Limited | Other services | 2023 |
| ANK Consulting Limited | Professional & scientific | 2025 |
| Anker Group 2023 Ltd | Wholesale & retail | 2023 |
| Ansec IA Ltd | Information & communication | 2007 |
| Antrim Car & Van Ltd | Wholesale & retail | 2026 |
| Antrim Carpentry and Design Limited | Construction | 2025 |
| Antrim Foodbank | Other services | 2026 |
| Antrim Leisure and Energy Project Limited | Construction | 2021 |
| Antrim Nails & Spa Limited | Other services | 2024 |
| Antrim Pest Control Limited | Administrative & support | 2024 |
| Antrim Private Swim School Ltd | Real estate | 2024 |
| Antrim Rovers Football Club Limited | Arts & recreation | 2023 |
| Antrim Specsavers Limited | Wholesale & retail | 2011 |
| Antrim Tile & Bath Ltd | Construction | 2014 |
| Antrim Towns Development Company Limited | Real estate | 1998 |
| Anya's Rooms Ltd | Real estate | 2026 |
| AO Contracts Ltd | Construction | 2025 |
| Aoaj Property Group Ltd | Real estate | 2026 |
| Apex Roofing & Joinery Ltd | Manufacturing | 2025 |
| Apostle Care Limited | Health & social care | 2024 |
| Arbarr-Ess Limited | Manufacturing | 2023 |
| ARC Acquisition Group Ltd | Professional & scientific | 2025 |
| ARC Design (NI) Limited | Professional & scientific | 2011 |
| Arranejace Limited | Health & social care | 2023 |
| Asbestos Environmental Limited | Water & waste | 2018 |
| Ascend by EJ Optics Ltd | Health & social care | 2025 |
| Asda Stores (Belfast) Limited | Wholesale & retail | 2020 |
| Ashgrove Consulting Limited | Professional & scientific | 2019 |
| Ashland Logistics Limited | Wholesale & retail | 2020 |
| ASN Construction Ltd | Construction | 2017 |
| Asnee LAB LP | | 2021 |
| Assure Compliance Services Ltd | Public administration | 2021 |
| Ateir Club Limited | Wholesale & retail | 2026 |
| Atkinson Quality Consulting Limited | Professional & scientific | 2023 |
| Atko Group Limited | Wholesale & retail | 2018 |
| Atlantic Seaweeds Ltd | Manufacturing | 2026 |
| Attach IE Limited | Wholesale & retail | 2023 |
| Audit Diagnostics (N.I.) Ltd | Manufacturing | 2016 |