| Arrow Technologies LP | | 2018 |
| Arthur Dodds & Co. Ltd | Professional & scientific | 1999 |
| Arthur's of Hillsborough Limited | Construction | 2019 |
| Ascension Software Ltd | Information & communication | 2025 |
| Asetica Clinic Ltd | Health & social care | 2024 |
| ASH Cremation Keepsake Ltd | Manufacturing | 2025 |
| Ashderg Contracts Limited | Construction | 2023 |
| Ashmour Balladon LLP | | 2024 |
| Ashmour Cocoon Limited | Professional & scientific | 2015 |
| Ashmour Developments Limited | Construction | 2003 |
| Ashmour Homes Ltd | Real estate | 2006 |
| Ashvale Farm Shop Ltd | Wholesale & retail | 2014 |
| Ashvale Meat Company Ltd | Wholesale & retail | 2021 |
| Asian Garden Massage Ltd | Health & social care | 2024 |
| Associated Pipeline Products Holdings Limited | Financial services | 2025 |
| Associated Pipeline Products Limited | Wholesale & retail | 1992 |
| Asure Global PEO Services Ltd | Administrative & support | 2026 |
| Asylia Ltd | Information & communication | 2006 |
| AT Fit Gym by Aaron Thompson & Rachael ORR Ltd | Arts & recreation | 2019 |
| Atbara Medical Limited | Health & social care | 2010 |
| ATG Electrical Ltd | Construction | 2023 |
| Athghin Center for Spiritual Formation Ltd | Other services | 2026 |
| Atlantic Trawlers Kilkeel Limited | Agriculture & fishing | 2011 |
| Atlas Women's Centre | Education | 2006 |
| Attention Autism Ltd | Education | 2023 |
| Attnx Ltd | Information & communication | 2020 |
| Audiospace Ltd | Wholesale & retail | 2011 |
| Aura ICU Limited | Other services | 2020 |
| Aurora Prime Real Estate Limited | Real estate | 2015 |
| Aurora Signs Ltd | Professional & scientific | 2023 |
| Auto Services & Marine Ltd | Wholesale & retail | 2021 |
| Auto Solutions N. I. Limited | Wholesale & retail | 2021 |
| Automation Impact LP | | 2020 |
| Automotive & Logistic Solutions Ltd | Wholesale & retail | 2024 |
| Automotive Smart Repair Solutions Limited | Wholesale & retail | 2024 |
| AVA Investments Limited | Real estate | 1995 |
| Aviator Entertainment LP | | 2022 |
| Avonmore Training Solutions Ltd | Education | 2016 |
| Awesome Brows & Beauty Ltd | Other services | 2026 |
| AWM Custom Engineering Ltd | Manufacturing | 2022 |
| Axion Insights Ltd | Information & communication | 2025 |
| Axisafety Training Ltd | Other services | 2023 |
| Aycareangels Limited | Health & social care | 2025 |
| Ayyoub Medical Ltd | Health & social care | 2020 |
| B & C Product Group Ltd | Wholesale & retail | 2026 |
| B and T Inns Limited | Hospitality | 1995 |
| B C H C Limited | Construction | 1991 |
| B J'S Fast Food Supplies Limited | Manufacturing | 1999 |
| B S Lift Limited | Professional & scientific | 2007 |
| B Supply Ltd | Manufacturing | 2025 |
| B'S Boutique Limited | Wholesale & retail | 2025 |
| B-Jay's Services Limited | Financial services | 2015 |
| B.E.S. International LP | | 2022 |
| Babiker Medical Ltd | Health & social care | 2025 |
| BACK2HEALTH Physio Ltd. | Other services | 2015 |
| Badger IOT Ltd | Professional & scientific | 2023 |
| Baguio Care NI Limited | Health & social care | 2016 |
| Bahs Ltd | Wholesale & retail | 2009 |
| Bailie Associates Limited | Professional & scientific | 2002 |
| Baillies Mills Accordion Band Ltd | Extraterritorial | 2011 |
| Bairnsdale Developments Limited | Construction | 2008 |
| Baked & Loaded Catering Ltd | Hospitality | 2024 |
| Ballycarngannon Ltd | Agriculture & fishing | 2025 |
| Ballygo (N.I.) Limited | Information & communication | 2024 |
| Ballygrainey Holdings Limited | Professional & scientific | 2019 |
| Ballyhill Limited | Real estate | 2017 |
| Ballyleagry Solar Farm Limited | Energy | 2025 |
| Ballymacbrennan Ltd | Energy | 2008 |
| Ballymena Domi Audiology Specsavers Limited | Wholesale & retail | 2026 |
| Ballymullan Limited | Transport & logistics | 2015 |
| Ballymullan Manor Management Company Limited | Households | 2021 |
| Ballymullan Property Company Ltd | Real estate | 2012 |
| Ballyquillan Holding Limited | Real estate | 2017 |
| Ballyrobin Enterprises Limited | Hospitality | 2012 |
| Ballyscolly Holdings Limited | Professional & scientific | 2019 |
| Ballyscolly Properties Limited | Real estate | 1994 |
| Ballysillan Hill Limited | Construction | 2016 |
| Ballywell Developments Ltd | Real estate | 2019 |
| Ballywildrick Farm Limited | Agriculture & fishing | 2018 |
| Baltic C Enterprises Limited | Wholesale & retail | 2012 |
| Baltic Coast Restaurants Limited | Wholesale & retail | 2015 |
| Baltics Invest LP | | 2018 |
| Baltor Systems Limited | Wholesale & retail | 1990 |
| Bambodeluxe Limited | Construction | 2025 |
| Bangor Road Developments Limited | Construction | 2014 |
| BAO BUN Botanic Ltd | Hospitality | 2024 |
| BAO BUN Lisburn RD Ltd | Hospitality | 2024 |
| Bar 15 Ltd | Hospitality | 2017 |
| Barbour Properties Ltd | Real estate | 2024 |
| Barking Style Boutique Limited | Other services | 2016 |
| Basingbridge Limited | Real estate | 2022 |
| Bawon Bawon Ltd | Hospitality | 2025 |
| Baytec Holdings Limited | Education | 2017 |
| BBL Mobile Limited | Hospitality | 2024 |
| BC Body Nutrition Ltd | Arts & recreation | 2020 |
| BC Body Nutrition Property Ltd | Real estate | 2022 |
| BC Commercial Property Limited | Real estate | 2023 |
| BCM International NI | Education | 2016 |
| BE a Better YOU Ltd | Other services | 2021 |
| BE Inspired to BE Limited | Professional & scientific | 2020 |