| 1 Oak Leisure Ireland Ltd | Hospitality | 2012 |
| 3 Elements Catering Ltd | Hospitality | 2020 |
| 360 Design & Fitout Ltd | Construction | 2015 |
| 3CANE Ltd | Construction | 2025 |
| 76 Granville Road Management Company Limited | Households | 2006 |
| 825 Contracts Ltd | Construction | 2026 |
| 92 Foods Ltd | Hospitality | 2024 |
| A & B Finlay Industrial Cleaning Ltd | Administrative & support | 2026 |
| A & M Windows & Doors Ltd | Manufacturing | 2006 |
| A & S Mechanical (N.I.) Ltd | Construction | 2011 |
| A B Agri Services (NI) Limited | Construction | 2012 |
| A OK Installations Limited | Construction | 2005 |
| A&M Bradley Developments Limited | Construction | 2018 |
| A. Higgins Contracts Limited | Construction | 2022 |
| A.H Superbikes Ltd | Wholesale & retail | 2020 |
| ABD Pizzas Limited | Hospitality | 2012 |
| Absolute Organic Wine Limited | Wholesale & retail | 2016 |
| Accumin Ltd | Wholesale & retail | 2017 |
| Accumin Solutions Ltd | Mining & quarrying | 2017 |
| Ace Oils Ltd | Wholesale & retail | 2014 |
| Acil Derya Ltd | Wholesale & retail | 2024 |
| Acorn (N.I) Holdings Ltd | Financial services | 2022 |
| Acson (N.I.) Limited | Information & communication | 2023 |
| ADM Pipe Installations Ltd | Manufacturing | 2003 |
| Adpax Developments Ltd | Other services | 1998 |
| Adpax Management Company Limited | Administrative & support | 1999 |
| Adrian & Ursula Booth NI Ltd | Construction | 2012 |
| Advanced Transport Solutions Ltd | Transport & logistics | 2023 |
| AEH Dental Ltd | Health & social care | 2026 |
| Aesthetically Beautiful by Danielle Coey Ltd | Other services | 2024 |
| Aesthetically Beautiful Weight Management Clinic Ltd | Other services | 2025 |
| AGC Systems T/A Rainbow Restoration Ltd | Construction | 2016 |
| Agile Sustainable Infrastructure Limited | Financial services | 2023 |
| Aidan Rice Ltd | Wholesale & retail | 2025 |
| AIG Enterprise Limited | Health & social care | 2025 |
| Air River Limited | Energy | 2011 |
| Airclear Ltd | Administrative & support | 2024 |
| Aisling Bremner Marketing Limited | Professional & scientific | 2021 |
| AJH Contracts Ltd | Administrative & support | 2021 |
| AJR Advisory Limited | Professional & scientific | 2021 |
| Alex Jane Limited | Manufacturing | 2016 |
| Aligned Atoms Ltd | Arts & recreation | 2026 |
| Alimas Property Limited | Financial services | 2026 |
| ALL Bout Chefs II Ltd | Administrative & support | 2024 |
| ALL Paint & Decor Ltd | Wholesale & retail | 2026 |
| Allstar Contracts Limited | Construction | 2013 |
| Allstar Investments Limited | Real estate | 2017 |
| Allstar Properties Limited | Real estate | 2016 |
| ALS Anderson Lifting Services Ltd | Mining & quarrying | 2025 |
| Alterno Limited | Manufacturing | 2017 |
| Amcpd Ltd | Financial services | 2024 |
| AMD Interior Design Ltd | Professional & scientific | 2024 |
| Amdn Holdings Ltd | Financial services | 2022 |
| AMG Plant Hire Ltd | Construction | 2021 |
| AMG Plant Testing Ltd | Construction | 2021 |
| Ampm Properties Limited | Real estate | 2006 |
| AMS (Advanced Motor Solutions) Ltd | Wholesale & retail | 2025 |
| AN Carn Distillery Ltd | Manufacturing | 2021 |
| Anahorish Renewables Limited | Energy | 2017 |
| Anderson Haulage Limited | Transport & logistics | 1973 |
| Anderson Interiors Limited | Manufacturing | 2019 |
| Andrew Bradley Limited | Construction | 1984 |
| ANN Wallace Limited | Wholesale & retail | 2025 |
| Annagh Engineering Limited | Manufacturing | 2017 |
| Antrim Road Management Ltd | Households | 2007 |
| Apex NRG Ltd | Construction | 2020 |
| Arches Physiotherapy Limited | Health & social care | 1999 |
| Ardanlee Limited | Hospitality | 2013 |
| Ardavon Management Company Limited | Households | 2019 |
| Ardreagh Formwork (NI) Ltd | Construction | 2018 |
| ARG Marketing Ltd | Information & communication | 2017 |
| ARK Kingdom CIC | Wholesale & retail | 2022 |
| Armour Tech Ltd | Wholesale & retail | 2025 |
| AS Contracts (2021) Ltd | Construction | 2021 |
| Ashbourne Heights Company Limited | Wholesale & retail | 2019 |
| ASM (DEF) Ltd | Professional & scientific | 1997 |
| ASM (M) Ltd | Professional & scientific | 1996 |
| ASM (NW) Ltd | Professional & scientific | 2014 |
| ASM Corporate Finance Ltd | Professional & scientific | 2024 |
| ATF Buildings Ltd | Construction | 2018 |
| Atlantic View Leisure Park Ltd | Hospitality | 2014 |
| Attainx Ltd | Information & communication | 2023 |
| Attni Limited | Construction | 2022 |
| Aughrim Energy Ltd | Professional & scientific | 2022 |
| Aura Sugaring Ltd | Other services | 2025 |
| Authentique Home Interiors Ltd. | Wholesale & retail | 2019 |
| Auto & Trailer Spares Limited | Wholesale & retail | 2004 |
| Automation Control Solutions Ltd | Professional & scientific | 2021 |
| AVL Rental Limited | Administrative & support | 2024 |
| B R Pans Limited | Hospitality | 2021 |
| B&P Agri Enterprises Limited | Transport & logistics | 2020 |
| B.M.K. Steel Ltd | Manufacturing | 2000 |
| Baby Angels Organisation Limited | Other services | 2017 |
| Babylon Financial Technology Ltd | Information & communication | 2025 |
| Baillie Martin Limited | Administrative & support | 2012 |
| Balance Podiatry Ltd | Health & social care | 2024 |
| Balanced Life Ireland Ltd | Wholesale & retail | 2025 |
| Balans Interiors Ltd | Professional & scientific | 2021 |
| Balfour Millhouse Management Limited | Hospitality | 2001 |
| Ballamilis Holdings Ltd | Financial services | 2023 |