| 20 Main Street Ltd | Hospitality | 2019 |
| A Nelson Building Ltd | Construction | 2022 |
| A Samuel Contracts Limited | Construction | 2026 |
| A T M Fabrication & Construction Ltd | Construction | 2006 |
| A.B Mechanical & Heating Services Limited | Construction | 2025 |
| A.G.M. (Distributors) Limited | Wholesale & retail | 1964 |
| AB Crane Services Ltd | Construction | 2021 |
| Abireo Animal Nutrition Ltd | Agriculture & fishing | 2025 |
| Abundant Coffee and Treats Limited | Hospitality | 2024 |
| Accelerateyourmolecule Ltd | Professional & scientific | 2024 |
| Access Communications and Engagement Ltd | Professional & scientific | 2023 |
| ACF Chemical and Leisure Supplies Ltd | Wholesale & retail | 2019 |
| Action Trauma Limited | Information & communication | 2017 |
| ADD Mechanical Ltd | Construction | 2026 |
| Adept Residential Limited | Professional & scientific | 2026 |
| ADS Mechanical Limited | Construction | 2018 |
| AEM Building and Joinery Ltd | Construction | 2024 |
| Aesthetics by DR Victoria Ltd | Health & social care | 2023 |
| AF Electrical (N.I.) Limited | Construction | 2024 |
| Agape Bridge CIC | Administrative & support | 2026 |
| AI Governance Standard Limited | Professional & scientific | 2026 |
| Ak's Catering Limited | Hospitality | 2018 |
| Algae Control IRE Limited | Agriculture & fishing | 2020 |
| Algae Weed Control Limited | Agriculture & fishing | 2020 |
| Annsborough Community Forum | Health & social care | 2012 |
| Anvil Consulting Services Limited | Professional & scientific | 2024 |
| Apache Pizza (Ballynahinch) 786 Ltd | Hospitality | 2023 |
| Apex Building and Joinery Limited | Construction | 2024 |
| Appappa Ltd | Information & communication | 2014 |
| Aqua Realty Ltd | Households | 2019 |
| AR Development (1) Limited | Construction | 2024 |
| Archion Design Ltd | Professional & scientific | 2020 |
| Ardnadarragh Ltd | Real estate | 2023 |
| Ardpatrick IT Solutions Limited | Information & communication | 2008 |
| ARK Glass Limited | Professional & scientific | 2012 |
| ARK Integrated Solutions Ltd | Manufacturing | 2017 |
| Arkver Ltd | Information & communication | 2012 |
| Armani’S Tanning Limited | Other services | 2026 |
| Armstran Consulting Ltd | Administrative & support | 2014 |
| Ashvale Haulage Co Down Ltd | Transport & logistics | 2015 |
| ASK I.T. (Northern Ireland) Ltd | Other services | 2007 |
| ATC Sales and Servicing Ltd | Wholesale & retail | 2026 |
| Athru Property Services Limited | Real estate | 2026 |
| Auspey Trading Limited | Manufacturing | 2017 |
| AVK Power Engineering Ltd | Professional & scientific | 2022 |
| AWC Consulting Ltd | Information & communication | 2025 |
| Axis Business Consulting Limited | Extraterritorial | 2012 |
| Aztec Chemicals (IRE) Limited | Wholesale & retail | 2023 |
| Bailiewood Management Company Limited | Households | 2007 |
| Ballyburren Limited | Agriculture & fishing | 2022 |
| Ballykine Stables Limited | Agriculture & fishing | 2024 |
| Ballymaglave Ltd | Professional & scientific | 2012 |
| Ballynahinch Business Park Limited | Other services | 2019 |
| Ballynahinch Creche Limited | Construction | 2010 |
| Ballynahinch Fuel Company Ltd | Mining & quarrying | 2000 |
| Ballynahinch Motor Factors Limited | Wholesale & retail | 2018 |
| Ballynahinch Property Services Limited | Real estate | 2013 |
| Ballynahinch Self Storage Ltd | Extraterritorial | 2024 |
| Ballynahinch Soft Play Limited | Hospitality | 2021 |
| Ballyowan Farm LLP | | 2019 |
| Bann Projects (NI) Ltd | Construction | 2025 |
| Barr Contracts Ltd | Administrative & support | 2020 |
| Bashfordsland Management Company Limited | Households | 2005 |
| BDF Mechanical Ltd | Construction | 2018 |
| Beau and Belle Kidswear Limited | Wholesale & retail | 2019 |
| BEC Electrical Ltd | Construction | 2012 |
| Beckett Hanlon Limited | Real estate | 2012 |
| Beechwood Exodus Limited | Financial services | 2024 |
| Beechwood Genesis Limited | Real estate | 2024 |
| BEL Catering Limited | Hospitality | 2019 |
| Bellamoon Limited | Manufacturing | 2016 |
| BEN and Hollys Little Play Village Ltd | Hospitality | 2025 |
| BES Contracts Ltd | Construction | 2016 |
| BH Farms Ltd | Financial services | 2025 |
| BH Paints & Hardware Ltd | Wholesale & retail | 2020 |
| Bible Quotes Belfast Limited | Manufacturing | 2017 |
| Blrc Limited | Wholesale & retail | 2004 |
| Blue Cedar Coffee Ltd | Hospitality | 2020 |
| Blue Cedar Garden Centre Ltd | Administrative & support | 2020 |
| Blue Cedar Landscaping Ltd | Administrative & support | 2023 |
| Bmpb Ltd | Information & communication | 2018 |
| Bowsie Electrical Limited | Construction | 2026 |
| Boxd Coffee Ltd. | Hospitality | 2025 |
| Branniff Construction Ltd | Construction | 2017 |
| Branniff Homes Ltd | Construction | 2017 |
| Branniff Property Letting and Sales Limited | Households | 2024 |
| Brian Dornan Ltd | Construction | 2026 |
| Brite Engineering Limited | Professional & scientific | 2020 |
| Broaghclough Holdings Ltd | Professional & scientific | 2015 |
| Brolly Aluminium Finishing Ltd | Manufacturing | 2006 |
| BRÓ38 Ltd | Hospitality | 2015 |
| Building IT Better NI Ltd | Education | 2025 |
| Burnpipe Ltd | Professional & scientific | 2019 |
| Bustaseed Limited | Wholesale & retail | 2017 |
| C & R Properties Limited | Construction | 1998 |
| C.F.C Ballynahinch Ltd | Hospitality | 2016 |
| Cafe 31 Downpatrick Ltd | Hospitality | 2019 |
| Cana Productions Ltd | Information & communication | 2018 |
| Candy Plus Ltd | Wholesale & retail | 2019 |
| Carnreagh Contracts Ltd | Construction | 2025 |