| 10 Glen Properties Limited | Real estate | 2020 |
| 10 Glen Property Development Limited | Construction | 2020 |
| 107 Eglinton Street Limited | Real estate | 2019 |
| 147 Snooker and Pool (N.I.) Limited | Arts & recreation | 2015 |
| 1886 Heritage Suffolk Lamb Limited | Manufacturing | 2023 |
| 1KE London Ltd | Construction | 2020 |
| 20 Broadway Ltd | Real estate | 2018 |
| 21 Construction Ltd | Construction | 2023 |
| 21 Healthcare Recruitment Ltd | Health & social care | 2022 |
| 27 Direct Ltd | Wholesale & retail | 2023 |
| 2MORROWS Commerce Ltd | Wholesale & retail | 2024 |
| 321SERVICES Ltd | Real estate | 2015 |
| 360 Properties Sales Ltd | Real estate | 2026 |
| 360 Property Lettings Ltd | Real estate | 2026 |
| 360 Synk Software Ltd | Information & communication | 2025 |
| 3D Contracts (NI) Ltd | Construction | 2017 |
| 463.IS Ltd | Wholesale & retail | 2023 |
| 4D Builders (NI) Limited | Construction | 2021 |
| 4D Properties (N.I.) Limited | Construction | 2015 |
| 7 Blooms Ltd | Wholesale & retail | 2026 |
| 7 Towers Pizza Ltd | Hospitality | 2023 |
| 77 Property Developments Ltd | Real estate | 2026 |
| A & L Developers Ltd | Construction | 2020 |
| A & P Louden Ltd | Mining & quarrying | 2019 |
| A & P Structural Engineering Limited | Professional & scientific | 2007 |
| A Bryson Designs Ltd. | Professional & scientific | 2011 |
| A C W Developments Ltd | Agriculture & fishing | 1999 |
| A C W Farming Ltd | Agriculture & fishing | 2016 |
| A Hogg Ltd | Construction | 2024 |
| A J Fuels Limited | | 2008 |
| A N E Solutions Ltd | Manufacturing | 2011 |
| A S F Engineering Limited | Manufacturing | 2000 |
| A SIX Properties Ltd | Real estate | 2020 |
| A&A Enterprises Ltd | Real estate | 2020 |
| A. 1. Brokers Limited | Financial services | 1983 |
| A.1. Finance Limited | Manufacturing | 1983 |
| A.C.E. Architectural Services Limited | Professional & scientific | 2020 |
| A.C.W. Homes Limited | Construction | 2002 |
| A.R.T. Engineering (N.I.) Ltd | Manufacturing | 2015 |
| A1 Electrics (N.I.) Limited | Wholesale & retail | 2022 |
| A24 Security Systems Limited | Administrative & support | 2024 |
| A2Z UKI Limited | Hospitality | 2020 |
| AAA Training Limited | Education | 2025 |
| Abbey Grange Management Company Ltd | Households | 2023 |
| Academy Apartments Limited | Real estate | 1987 |
| Ace Fixings (Ireland) Ltd | Extraterritorial | 2005 |
| Ace Fixings Ltd | Wholesale & retail | 2005 |
| ACM Valuations and Trading Ltd | Wholesale & retail | 2025 |
| ACS Supplies Ltd | Wholesale & retail | 2023 |
| Active Listening | Other services | 2010 |
| Actovation Limited | Administrative & support | 2001 |
| Adams Brothers Contractors Limited | Construction | 2010 |
| Adams Farm Ltd | Agriculture & fishing | 2017 |
| Adasalign Calibration Systems Ltd | Wholesale & retail | 2026 |
| ADC Events Ltd | Hospitality | 2026 |
| Addison Enterprises Limited | Construction | 2018 |
| ADS Homes (N.I.) Ltd | Construction | 2026 |
| ADV Developments Ltd | Construction | 2007 |
| Advent Agriland Limited | Real estate | 2022 |
| Advent Asset Management Ltd | Professional & scientific | 2013 |
| Advent Biogas Limited | Energy | 2018 |
| Advent Energy Ltd | Professional & scientific | 2010 |
| Advent Wind Banbridge Limited | Energy | 2013 |
| Aerospace Metal Finishers Limited | Manufacturing | 2002 |
| Aerosubs Limited | Manufacturing | 1996 |
| Aestheticrx Medical Aesthetics Limited | Other services | 2024 |
| AF Auto Solutions Ltd | Wholesale & retail | 2025 |
| Affordable Food Collective (MID and East Antrim) Ltd | Wholesale & retail | 2026 |
| Affordable OFF Gird Energy Limited | Other services | 2022 |
| Afmg Global Ltd | Professional & scientific | 2023 |
| African Clothing Exports Limited | Real estate | 1997 |
| Aggies Contract Services Ltd | Manufacturing | 2024 |
| Agnew Holdings Limited | Professional & scientific | 2018 |
| Agon Limited | Construction | 2011 |
| Agri Limited | Agriculture & fishing | 2021 |
| Agri Train NI Ltd | Education | 2024 |
| Agriplant Diagnostics Ltd | Manufacturing | 2026 |
| AGS Building & Civil Engineering Ltd | Real estate | 2016 |
| Agtec Investments Limited | Real estate | 2003 |
| Ahoghill Community Development Company | Real estate | 2005 |
| Ahoghill Community Property Development Company Ltd | Real estate | 2005 |
| AI Semen Supply Centre Limited | Agriculture & fishing | 2023 |
| Aicken Limited | Information & communication | 2023 |
| Aickenproperty Limited | Real estate | 2025 |
| Aiken Accountants Ltd | Professional & scientific | 2015 |
| Air Commercial Services Ltd. | Wholesale & retail | 2013 |
| Airconserv Limited | Manufacturing | 2011 |
| Ajdw Maintenance Limited | Real estate | 2018 |
| Ajokeabey Ltd | Wholesale & retail | 2023 |
| AJT Aviation Ltd | Professional & scientific | 2025 |
| Alastair Mckillop Accountancy and Taxation | Professional & scientific | 2015 |
| Albert Graham Limited | Wholesale & retail | 1976 |
| Alder Living Ltd | Real estate | 2019 |
| Alexander Bonar & Co. Limited | Construction | 1976 |
| Alis Barber 007 Ltd | Other services | 2026 |
| ALL Spares Marine Ltd | Wholesale & retail | 2016 |
| All-Tex Recyclers Limited | Manufacturing | 2008 |
| Allia (N.I.) Limited | Hospitality | 2016 |
| Allure Home Developments Ltd | Real estate | 2024 |
| Alpett Ltd | Professional & scientific | 2024 |