| Autoradz Limited | Wholesale & retail | 2010 |
| Autoservices (Northern Ireland) Limited | Professional & scientific | 1951 |
| Autoweld Belfast Ltd | Professional & scientific | 2026 |
| Autoworx Carrick Limited | Wholesale & retail | 2019 |
| AV (2021) Ltd | Wholesale & retail | 2021 |
| AV Employees Trustees Limited | Extraterritorial | 2023 |
| AV PVT Ltd. | Hospitality | 2014 |
| AVA Belfast CIC | Education | 2019 |
| AVA Garage Ltd | Wholesale & retail | 2015 |
| AVA Investments R&D LP | | 2019 |
| AVA the Anteater and Friends Ltd | Arts & recreation | 2023 |
| AVA Training & Cosmetics Ltd | Wholesale & retail | 2021 |
| Avah Home Care Limited | Public administration | 2023 |
| Avalon Investments (N.I.) Ltd | Real estate | 2025 |
| Avalon Spine Centre Ltd | Real estate | 2015 |
| Avalon Sport and Casual Wear Ltd | Manufacturing | 2020 |
| Avat Healthcare Ltd | Administrative & support | 2025 |
| Avatom QA Ltd | Information & communication | 2026 |
| AVC Hire (NI) Limited | Administrative & support | 2019 |
| Avec Solutions Ltd | Information & communication | 1998 |
| Avendor Holding LP | | 2023 |
| Avenir Technical Services Ltd | Professional & scientific | 2015 |
| Aventas Manufacturing Group Holdco Limited | Financial services | 2011 |
| Aventas Property Limited | Real estate | 2014 |
| Avenue Media Limited | | 1999 |
| Avenue Metal Recycling Ltd | Wholesale & retail | 2010 |
| Avenue Supplies Ltd | Wholesale & retail | 2025 |
| Avenue Vape Ltd | Wholesale & retail | 2023 |
| Averra Health Ltd | Health & social care | 2026 |
| AVI Swap Ltd | Other services | 2025 |
| Avia INT Service L.P. | | 2018 |
| Aviation Fuel Training Services Limited | Administrative & support | 2018 |
| Aviatrade Corp. LP | | 2018 |
| Avilamedia C.I.C. | Professional & scientific | 2019 |
| Avnel Beauty Spa Ltd | Other services | 2023 |
| Avoca Handweavers NI Limited | Wholesale & retail | 2007 |
| Avoca Homes Limited | Construction | 2019 |
| Avoca Rose Limited | Construction | 2018 |
| Avocet Cleaning Limited | Administrative & support | 2025 |
| Avoda Agencies Limited | Professional & scientific | 2020 |
| Avoda Construction Ltd | Construction | 2023 |
| Avolton Industries LP | | 2017 |
| Avolv Kitchens Ltd | Manufacturing | 2026 |
| Avonbeg House Limited | Real estate | 2023 |
| Avonlee Soap Co.Uk Ltd | Wholesale & retail | 2022 |
| Avrio Holdings Ltd | Financial services | 2022 |
| Avrio Logistics Ltd | Transport & logistics | 2009 |
| Avspni | Professional & scientific | 2019 |
| Avtex (N.I.) Limited | Manufacturing | 2020 |
| Avvic Private Ltd | Construction | 2020 |
| AVW Global Ltd | Arts & recreation | 2012 |
| AW Film Services Ltd | Construction | 2023 |
| AW Nutrition Solutions Limited | Health & social care | 2025 |
| AW Tech Group Limited | Information & communication | 2023 |
| Awais Groove Ltd | Wholesale & retail | 2025 |
| AWG Developments Limited | | 1999 |
| AWH50 Ltd | Professional & scientific | 2024 |
| AWI Capiuial Limited | Wholesale & retail | 2023 |
| AWJ Property Developments Ltd | Real estate | 2012 |
| AWS Group Ltd | Wholesale & retail | 2023 |
| Axea Investments Limited | Financial services | 2025 |
| Axel Estates Ltd | Construction | 2022 |
| Axelara Ltd | Wholesale & retail | 2026 |
| Axia Procurement Ltd | Professional & scientific | 2021 |
| Axial Medical Printing Limited | Professional & scientific | 2013 |
| Axion Global Technologies Limited | Professional & scientific | 2026 |
| Axis Composites Limited | Manufacturing | 2010 |
| Axis Healthcare Recruitment Limited | Administrative & support | 2025 |
| Axis Nursing Agency Ltd | Administrative & support | 2018 |
| Axis Technology & Development Limited | Manufacturing | 2013 |
| AXL Audiovisual Ltd | Other services | 2023 |
| Axon Financial Systems Limited | Information & communication | 2014 |
| Ayaat Spice Ltd | Hospitality | 2026 |
| Ayan Kebabs Ltd | Hospitality | 2026 |
| Ayanda Kurdi Ltd | Other services | 2025 |
| Ayat Spice Ltd | Hospitality | 2023 |
| Ayat Subs Ltd | Hospitality | 2013 |
| Aydlan Properties Ltd | Real estate | 2024 |
| Aydzo Ltd | Public administration | 2025 |
| Ayebrooke Ltd | Wholesale & retail | 2025 |
| Aylwards Trading Limited | Professional & scientific | 2025 |
| AZ Amode LP | | 2018 |
| AZ Interior Design Ltd Limited | Wholesale & retail | 2023 |
| AZ Van Services Ltd | Transport & logistics | 2022 |
| Azac Castlerock Limited | Wholesale & retail | 2020 |
| Azara Processing LP | | 2019 |
| Azarbuttlogistics Limited | Wholesale & retail | 2025 |
| Azaz ALI Limited | Health & social care | 2024 |
| Azeem Mall Ltd | Wholesale & retail | 2025 |
| Azienda DI Casalattico Limited | Financial services | 2026 |
| Azlan Bilal Ltd | Hospitality | 2022 |
| Azone Hong Kong Limited | Wholesale & retail | 2025 |
| Aztec Lubricants NI Ltd | Wholesale & retail | 2021 |
| Aztec Roofing and Property Maintenance Ltd | Construction | 2023 |
| Aztech Scaffolding (NI) Ltd | Construction | 2011 |
| Azure Media Services Limited | Professional & scientific | 2025 |
| AZY Properties Limited | Real estate | 2026 |
| Azzopardi Northern Limited | Financial services | 2025 |
| B & C Blogging LLP | | 2021 |
| B & C Investment Partnership Ltd | Financial services | 2023 |