| Anscombe Surveying Ltd | Professional & scientific | 2021 |
| Apex Electrics and Solar Ltd | Construction | 2026 |
| Apmc Group Ltd | Real estate | 2024 |
| Apple Blossom Construction Limited | Construction | 2019 |
| Apple Orchard Construction (Holborn AVE) Ltd | Construction | 2022 |
| Apple Orchard Construction Forkhill Ltd | Construction | 2022 |
| Apple Orchard Construction Ltd | Construction | 2011 |
| Apple Orchard Holdings Ltd | Construction | 2017 |
| Apple Orchard Properties Ltd | Real estate | 2006 |
| Appleby Careers Project Limited | Education | 1998 |
| Appleby Trust - the | Education | 2001 |
| Appleyard Management Co Limited - the | Households | 2004 |
| Aqua Bhean Ltd | Professional & scientific | 2013 |
| Aquarius Pumps Limited | Construction | 2003 |
| Aquarius Pumps N.I. Ltd | Construction | 2026 |
| ARC C Solutions Limited | Information & communication | 2021 |
| ARC Contract Services Ltd | Construction | 2019 |
| Ardeelin Holdings Ltd | Information & communication | 2023 |
| Ardeelin Ltd | Information & communication | 2022 |
| Ardgonnell Farm Ltd | Extraterritorial | 2022 |
| ARK Profiles Ltd | Manufacturing | 2014 |
| Armada Central Ltd | Information & communication | 2007 |
| Armadale (NI) Limited | Professional & scientific | 2010 |
| Armadale Small Animals Ltd | Professional & scientific | 2023 |
| Armagh (Ireland) Overseas Contracts Limited | Professional & scientific | 2015 |
| Armagh Associates Limited | Professional & scientific | 2025 |
| Armagh Auto Sales Limited | Wholesale & retail | 2019 |
| Armagh Blooms & Gifts Ltd | Wholesale & retail | 2012 |
| Armagh Business Park Limited | Administrative & support | 2012 |
| Armagh Car Breakers Ltd | Water & waste | 2014 |
| Armagh Child Contact Centre Ltd | Health & social care | 2006 |
| Armagh Chiropractic Clinic Limited | Health & social care | 2011 |
| Armagh City Townscape Heritage Partnership Limited | Professional & scientific | 2018 |
| Armagh Coaches Ltd | Transport & logistics | 2015 |
| Armagh County Agricultural Show Society | Agriculture & fishing | 2003 |
| Armagh Decor Ltd | Construction | 2011 |
| Armagh Denture Clinic Limited | Health & social care | 2014 |
| Armagh Design Ltd | Professional & scientific | 2022 |
| Armagh Economic Development Group | Administrative & support | 2000 |
| Armagh Electrical Supplies Limited | Wholesale & retail | 2023 |
| Armagh Engineering Ltd | Professional & scientific | 2024 |
| Armagh Enterprises Holdings Limited | Professional & scientific | 2015 |
| Armagh Enterprises Limited | Manufacturing | 2005 |
| Armagh Fisheries Limited | Arts & recreation | 1962 |
| Armagh Fitness Works Limited | Arts & recreation | 2016 |
| Armagh Garden Sheds Limited | Manufacturing | 2025 |
| Armagh Healthcare Limited | Real estate | 1998 |
| Armagh Hiab Crane Hire & Storage Solutions Ltd | Administrative & support | 2021 |
| Armagh Investments Limited | Construction | 2025 |
| Armagh Nails & Beauty Ltd | Other services | 2022 |
| Armagh OIL Direct Limited | Professional & scientific | 2013 |
| Armagh Ortho Animal Care Ltd | Professional & scientific | 2023 |
| Armagh Pest Control Ltd | Administrative & support | 2025 |
| Armagh Pipers Club | Arts & recreation | 2013 |
| Armagh Potato Company Ltd | Hospitality | 2002 |
| Armagh Refrigeration Services Ltd | Manufacturing | 2012 |
| Armagh Sports & Trophies Limited | Wholesale & retail | 2012 |
| Armagh Theatre Company Limited | Arts & recreation | 1998 |
| Armagh Tigers | Health & social care | 2022 |
| Armagh Timber Products Limited | Manufacturing | 2015 |
| Armagh Tree Surgery Ltd | Agriculture & fishing | 2025 |
| Armagh Tyrone Wellbeing Collective CIC | Health & social care | 2024 |
| Armagh VET Station Ltd | Professional & scientific | 2025 |
| Armatile Holdings Limited | Financial services | 2023 |
| Armatile Limited | Wholesale & retail | 1985 |
| Artal Links Ltd | Transport & logistics | 2007 |
| Artificial Grass N.I Ltd | Wholesale & retail | 2022 |
| Artisan by G&R Ltd | Hospitality | 2021 |
| Ashtree Farm Ltd | Agriculture & fishing | 2025 |
| Ashview Bricklaying Ltd | Construction | 2026 |
| Ashview Plant Limited | Construction | 2019 |
| ASI Contracts Limited | Construction | 2023 |
| Aslam Ghumman and Sons Ltd | Hospitality | 2019 |
| ASR Mechanical Services Ltd | Construction | 2025 |
| Astana Trading Co Ltd | Wholesale & retail | 2026 |
| Atlantis Holdings (N.I.) Limited | Financial services | 2018 |
| Atlas for Industry Ltd | Manufacturing | 2002 |
| ATR (N.I) Ltd | Financial services | 2022 |
| Aughnacloy Trade Sales Ltd | Wholesale & retail | 2018 |
| Aughnagurgan Property Ltd | Real estate | 2024 |
| Aura Cacao Ltd | Wholesale & retail | 2024 |
| Austin Mckeown Contracts Ltd | Construction | 2017 |
| Auto Seekers (NI) Ltd | Wholesale & retail | 2006 |
| Autobits Motor Store Limited | Wholesale & retail | 2017 |
| Automata Solutions Ltd | Information & communication | 2026 |
| Avenue Contracts (NI) Limited | Construction | 2011 |
| Avolon Blinds (a) Ltd | Manufacturing | 2019 |
| Azil Storage Systems Ltd | Construction | 2018 |
| B Hughes Holdings Limited | Real estate | 2022 |
| B P Mckernan Contracts Limited | Mining & quarrying | 2014 |
| B&G Energy Ltd | Administrative & support | 2015 |
| Baca Contracts Ltd | Professional & scientific | 2026 |
| Balkan Shop Ltd | Wholesale & retail | 2020 |
| Ballindarragh Poultry Farm Ltd | Agriculture & fishing | 2011 |
| Ballyards Charitable Trust | Other services | 2010 |
| Ballyards Consulting Ltd | Professional & scientific | 2015 |
| Ballyards Enterprise Ltd | Arts & recreation | 2026 |
| Ballyards Holdings Ltd | Financial services | 2023 |
| Ballyards Poultry | Agriculture & fishing | 2014 |
| Ballybrolly Construction Limited | Construction | 2024 |