| Apollo College Ltd | Education | 2021 |
| Apollo Rigging Services Ltd | Construction | 2025 |
| Apollo Rock Ltd | Real estate | 2021 |
| Apollo TV & Film Services Ltd | Information & communication | 2026 |
| Apolonia Consulting Services Ltd | Administrative & support | 2022 |
| Apopsis Property Limited | Real estate | 2017 |
| App Wave Studios Limited | Information & communication | 2014 |
| Appess Ltd | Information & communication | 2020 |
| Apple Distribution International Limited | Wholesale & retail | 2025 |
| Apple Mint Florist Ltd | Wholesale & retail | 2021 |
| Apple Office Solutions Limited | Wholesale & retail | 2006 |
| Apple Recruitment Belfast Ltd | Administrative & support | 2014 |
| Applecore Recycling Limited | Manufacturing | 2015 |
| Applegreen BK (NI) Limited | Wholesale & retail | 2015 |
| Applegreen Service Areas NI Limited | Wholesale & retail | 2012 |
| Appleton Trade Ltd | Wholesale & retail | 2024 |
| Appletree House Limited | Information & communication | 1991 |
| Appletree Press Limited -the | Information & communication | 1965 |
| Appliance Testing NI Ltd | Professional & scientific | 2017 |
| Applied Behaviour Solutions Community Interest Company | Administrative & support | 2025 |
| Apprisi Limited | Administrative & support | 2017 |
| Approachable Group Limited | Hospitality | 2015 |
| Apps Infosystems Limited | Information & communication | 2007 |
| Apricot Health Limited | Health & social care | 2018 |
| Apricot Insurance Services Limited | Financial services | 2011 |
| Apsley Hall Assembly | Other services | 2024 |
| Aptitude Support Ltd | Professional & scientific | 2025 |
| Aptrouter Ltd | Information & communication | 2025 |
| APW Fire Protection Limited | Construction | 2007 |
| Aqabela Ltd | Professional & scientific | 2020 |
| Aqeel Prime Ltd | Wholesale & retail | 2025 |
| Aqromarket Servis LP | | 2017 |
| Aqua Stratum Limited | Wholesale & retail | 2026 |
| Aqua Support Services Ltd | Administrative & support | 2026 |
| Aqua Trustees Number 10 Limited | Other services | 2019 |
| Aqua Trustees Number 21 Limited | Other services | 2020 |
| Aqua Trustees Number 22 Limited | Other services | 2020 |
| Aqua Trustees Number 25 Limited | Other services | 2020 |
| Aqua Trustees Number 26 Limited | Other services | 2020 |
| Aqua Trustees Number 3 Limited | Other services | 2019 |
| Aqua Trustees Number 4 Limited | Other services | 2019 |
| Aqua Trustees Number 5 Limited | Other services | 2019 |
| Aqua Trustees Number 6 Limited | Other services | 2019 |
| Aqua Trustees Number 7 Limited | Other services | 2019 |
| Aqua Trustees Number 8 Limited | Other services | 2019 |
| Aqua Trustees Number 9 Limited | Other services | 2019 |
| Aquababes (NI) Ltd | Other services | 2013 |
| Aqualoom Limited | Wholesale & retail | 2024 |
| Aquaproduct LP | | 2019 |
| Aquaq Clinical Limited | Professional & scientific | 2014 |
| Aquarium Exploris Limited | Arts & recreation | 2016 |
| AR Maintenance Solutions Limited | Administrative & support | 2008 |
| AR Pressure Washers Ltd | Wholesale & retail | 2022 |
| AR Sports Equipment Ltd | Wholesale & retail | 2022 |
| Ar-Dor Beauty Limited | Extraterritorial | 2011 |
| Arabesque Gymnastics Limited | Other services | 2018 |
| Arabesque Gymnastics N.I. CIC | Other services | 2025 |
| Arabica Investments Ltd | Hospitality | 2013 |
| Arabica Limited | Hospitality | 2003 |
| Aramune Technologies Limited | Professional & scientific | 2021 |
| Arapa Limited | Construction | 2020 |
| Aravir Limited | Real estate | 2018 |
| Aray Homes Ltd | Real estate | 2024 |
| Arberi Karrabecaj Ltd | Other services | 2021 |
| Arbutus Hospitality Ltd | Hospitality | 2017 |
| ARC Air Support Ltd | Construction | 2024 |
| ARC Investing Limited | Construction | 2017 |
| ARC Quarries Ltd | Mining & quarrying | 2018 |
| ARC Regulatory Limited | Professional & scientific | 2010 |
| ARC Ventures Ltd. | Wholesale & retail | 2023 |
| Arca Investments Limited | Real estate | 2024 |
| Arcade Studios Ltd | Arts & recreation | 2020 |
| Arcadia Green Coffee Ltd | Wholesale & retail | 2023 |
| Arcal Ltd | Professional & scientific | 2018 |
| Arcet Global Limited | Administrative & support | 2019 |
| Archean Mining Consultants UK Ltd | Mining & quarrying | 2025 |
| Archelon IT Solution Ltd | Information & communication | 2021 |
| Archeon Limited | Information & communication | 2025 |
| Archer Advertising Ltd | Professional & scientific | 2004 |
| Archer Automobiles Ltd | Wholesale & retail | 2009 |
| Archer Services Limited | Construction | 2024 |
| Arches Car Wash Ltd | Wholesale & retail | 2020 |
| Arches Lighting Centre Ltd | Wholesale & retail | 2016 |
| Archetype Design Ltd | Manufacturing | 2021 |
| Archie’S 2026 Ltd | Hospitality | 2026 |
| Architectural Ceramics Ltd | Construction | 2013 |
| Architectural Salvage Limited | Wholesale & retail | 2018 |
| Architecture & Design Office Ltd | Professional & scientific | 2015 |
| Archway Aviation Services Limited | Manufacturing | 2025 |
| Arco Commerce Ltd | Wholesale & retail | 2025 |
| Arcoh Holdings Limited | Financial services | 2021 |
| Arcstone Property Ltd | Hospitality | 2025 |
| Arcus Estates Ltd | Real estate | 2012 |
| ARD Baillie 4 Ltd | Real estate | 2020 |
| ARD Baillie 4&5 Limited | Construction | 2023 |
| Ard-Na-Hona Management Company Limited | Households | 2021 |
| Ardan Ventures Ltd | Financial services | 2026 |
| Ardara Management Services Limited | Real estate | 1985 |
| Ardbryan Ltd | Real estate | 2024 |
| Ardcarmon Limited | Wholesale & retail | 2014 |