| (NI) Keep ‘ER LIT Ltd | Wholesale & retail | 2021 |
| 1 - 3 Dunisland Ltd | Households | 2014 |
| 10 Ballynahinch Street Management Company Limited | Households | 2022 |
| 154 Group Limited | Agriculture & fishing | 2019 |
| 17-18 Bush Manor Management Ltd | Households | 2026 |
| 219-221 Saintfield Road Management Limited | Households | 2016 |
| 288 Antrim Road Management Limited | Households | 2014 |
| 361 Growth Ltd | Professional & scientific | 2013 |
| 3SIXTY Networks Limited | Information & communication | 2012 |
| 436 Antrim Road Management Ltd | Households | 2021 |
| 493K Limited | Manufacturing | 2003 |
| 5 Corners Guest Inn Limited | Hospitality | 2022 |
| 6ER Distribution Limited | Wholesale & retail | 2014 |
| A & B Trading Ltd | Hospitality | 2003 |
| A to BT Group Ltd | Transport & logistics | 2023 |
| A&P TWT Ltd | Water & waste | 2019 |
| A. Holmes Group Ltd | Financial services | 2022 |
| A. Holmes Properties Ltd | Construction | 2007 |
| A.F.W. Maintenance Limited | Extraterritorial | 2005 |
| A.L.C.O. Holdings Ltd | Real estate | 2022 |
| A1 Property Services Group Ltd | Real estate | 2024 |
| Aabro Properties Ltd | Real estate | 2025 |
| Abbey Land & Property Management Co. Ltd-The | Households | 2002 |
| Abbey Properties (NI) Ltd | Real estate | 2013 |
| Abbey Properties Investments (NI) Ltd | Real estate | 2025 |
| Abbey Real Estate (N.I.) Limited | Real estate | 2018 |
| Abbeycleancare Ltd | Administrative & support | 2021 |
| Abbeydene Court Apartments Limited | Administrative & support | 1995 |
| Abercorn Apartment Management Limited | Households | 1996 |
| Abercorn Consultancy Ltd | Financial services | 2020 |
| Abercorn Management Co Ltd | Extraterritorial | 2010 |
| Accounting Services (NI) Limited | Professional & scientific | 2003 |
| Achill Rock Services Limited | Extraterritorial | 2016 |
| Actions NOT Words | Education | 2013 |
| AD a Tint Ltd | Professional & scientific | 2025 |
| Adams Grid Services Ltd | Professional & scientific | 2012 |
| Advance Energy Limited | Energy | 2022 |
| Advanced Care Training Ltd | Education | 2020 |
| Advanced Chimney Solutions Ltd | Extraterritorial | 2003 |
| Advanced Ventilation Solutions Ltd | Manufacturing | 2018 |
| Aepe Ltd | Health & social care | 2026 |
| African Forests Consulting Limited | Professional & scientific | 2022 |
| AFW Developments Limited | Real estate | 2007 |
| Agnew Mitchell & Cairns Limited | Professional & scientific | 2011 |
| Agri-Research (Ireland) Limited | Transport & logistics | 1996 |
| AH Architect Ltd | Professional & scientific | 2009 |
| Aikin Square Management Ltd | Households | 2021 |
| Airdash Ltd | Information & communication | 2025 |
| Airlee Place Ltd | Real estate | 2021 |
| AJ & JA Wilson Ltd | Agriculture & fishing | 2011 |
| AJV Business Holdings Limited | Financial services | 2023 |
| AJV Business Services Limited | Administrative & support | 2013 |
| Alderwood Lane Management Ltd | Households | 2016 |
| Alexander Mcconnell Limited | Hospitality | 1972 |
| Alexandra Mews (Newtownards) Management Company Limited | Households | 2021 |
| Allenbrook Management Company Limited | Extraterritorial | 2002 |
| Allied Financial Consultancy Limited | Financial services | 2009 |
| Allied Trailer Lease Ltd | Administrative & support | 2021 |
| Allstars Dance Academy CIC | Arts & recreation | 2025 |
| Alpha Platinum Ltd | Wholesale & retail | 2026 |
| Alternative Wedding Cars NI Ltd. | Transport & logistics | 2005 |
| AM Construction Consulting Limited | Professional & scientific | 2018 |
| AM Insulation Limited | Extraterritorial | 2023 |
| Amara AID Limited | Other services | 2001 |
| AMC Consultancy Group Ltd | Professional & scientific | 2019 |
| Amigo Studios Ltd | Information & communication | 2013 |
| Ammlee Group International Limited | Construction | 2015 |
| Amplifi Solutions Ltd | Professional & scientific | 2014 |
| Amplify Consultancy Limited | Professional & scientific | 2023 |
| Anaae Ltd | Real estate | 2022 |
| Ancore Services Ltd | Construction | 2011 |
| Ancre Fit One Ltd | Arts & recreation | 2024 |
| Ancre Fit Two Ltd | Arts & recreation | 2024 |
| Anderson Investments Limited | Real estate | 1985 |
| Angels Keep Wellness Ltd | Health & social care | 2025 |
| Annagole Property Management Ltd | Extraterritorial | 2002 |
| Annahilt Gate Management Company Limited | Households | 2010 |
| Annahugh Hill Management Company Limited | Extraterritorial | 2007 |
| Anthony Hopkins Limited | Arts & recreation | 2025 |
| Antrim Coast Estates Ltd | Construction | 2023 |
| Antrim Hills Spring Water Company Limited | Manufacturing | 1989 |
| Apex Financial Management Limited | Professional & scientific | 2012 |
| Apex Hearing (N.I.) Ltd | Wholesale & retail | 2019 |
| Apex Hearing Solutions (UK) Limited | Health & social care | 2016 |
| Apex NI Developments Limited | Construction | 2026 |
| Apex NI Property Services Ltd | Real estate | 2023 |
| Apiary Records Ltd | Information & communication | 2026 |
| Apple Tree Lane Management Company Limited | Households | 2008 |
| Appleton Meadows Management Company Ltd | Households | 2022 |
| Aprm Properties Limited | Financial services | 2020 |
| Architectural Engineering & Manufacturing Design Company Limited | Agriculture & fishing | 1984 |
| Ardent Technologies Limited | Wholesale & retail | 2025 |
| Ardilea Holdings Limited | Financial services | 2022 |
| Ardmillan Management Company Limited | Households | 2004 |
| Ardmillan Mill Pond Ltd | Extraterritorial | 2012 |
| Ardnamara Property Management Co Ltd | Households | 2016 |
| Ardwin Technologies Ltd | Manufacturing | 2023 |
| ARM Software Solutions Ltd | Professional & scientific | 2024 |
| ARW Property Company | Financial services | 2020 |
| Ascef Ltd | Wholesale & retail | 2014 |