| Boldcustoms&Crafts Ltd | Professional & scientific | 2025 |
| Bonita Ltd | Wholesale & retail | 2026 |
| Bonon Luck Ltd | Wholesale & retail | 2025 |
| Bool IT Ltd | Information & communication | 2013 |
| Boom Z Limited | Manufacturing | 2024 |
| Borderline Productions Limited | Information & communication | 1998 |
| BOS Restaurant NI Ltd | Hospitality | 2017 |
| Bostreshuihuaderetail Ltd | Wholesale & retail | 2025 |
| Boult ISE Limited | Wholesale & retail | 2024 |
| Boyce Accounts Ltd | Professional & scientific | 2026 |
| Boyce Estates Ltd | Real estate | 2024 |
| Boyd & Henry Ltd | Professional & scientific | 2016 |
| Boyd Rice Solicitors Limited | Professional & scientific | 2017 |
| BPH Ltd | Real estate | 2021 |
| Braggart Limited | Wholesale & retail | 2025 |
| Braille Limited | Wholesale & retail | 2025 |
| Braise Limited | Wholesale & retail | 2025 |
| Bramble Services Ltd | Information & communication | 2019 |
| Branch OUT Community Group Ltd | Education | 2021 |
| Braniel Park Apartments Limited | Households | 2023 |
| Brassiere Limited | Wholesale & retail | 2025 |
| Brave ME Ltd | Wholesale & retail | 2025 |
| Breeches Limited | Wholesale & retail | 2025 |
| Breezemount Electrical & Hydraulics Limited | Professional & scientific | 1976 |
| Breneithical Ltd | Wholesale & retail | 2023 |
| Brethren Limited | Wholesale & retail | 2025 |
| Brian Boyle Ltd | Wholesale & retail | 2025 |
| Brian Darragh Ltd | Wholesale & retail | 2025 |
| Brian Johnston Ltd | Construction | 2022 |
| Brian Mcknight Ltd | Wholesale & retail | 2025 |
| Brian Taylor Management Services Ltd | Professional & scientific | 2015 |
| Brian Urquhart Limited | Wholesale & retail | 2025 |
| Bridewell Coffee Ltd | Hospitality | 2024 |
| Brite Spark Electrical Ltd | Construction | 2019 |
| Broanaderetail Ltd | Wholesale & retail | 2025 |
| Bronzing Room N.I Ltd | Other services | 2025 |
| Bsclaire Ltd | Wholesale & retail | 2024 |
| BTH Couriers Ltd | Transport & logistics | 2025 |
| Bulong Ltd | Wholesale & retail | 2025 |
| Burch Autos Limited | Wholesale & retail | 2021 |
| Buri Shopbar Limited | Wholesale & retail | 2025 |
| Burr Point Management Company Ltd | Households | 2014 |
| Business Micro Systems Ltd | Information & communication | 2018 |
| Butterfly Ireland Limited | Other services | 2023 |
| Butterlump Cottage Ltd | Hospitality | 2023 |
| Button Your Beak Productions Ltd | Information & communication | 2015 |
| BY Caitlyn Collection Ltd | Other services | 2023 |
| BY S. Property Limited | Households | 2025 |
| Byrne Peter Ltd | Wholesale & retail | 2025 |
| C and C Chairs Limited | Other services | 2016 |
| C R Mcgready & Co Limited | Professional & scientific | 2002 |
| C&D Family Homes Ltd | Real estate | 2026 |
| C&S (Ballynahinch) Limited | Construction | 2023 |
| C&S (Glasgow) Limited | Real estate | 2021 |
| C&S (Newtownards) Limited | Real estate | 2021 |
| C&S (Quarry Heights 2) Limited | Construction | 2023 |
| C&S (Quarry Heights) Limited | Construction | 2022 |
| C&S(Green Road) Limited | Construction | 2024 |
| C.T. Andrews Medical Legal Ltd | Health & social care | 2015 |
| CA Engineering Consultancy Ltd | Professional & scientific | 2017 |
| CAB Ground Engineering Limited | Construction | 2020 |
| CAB Plant Ltd | Construction | 2016 |
| Cabcrete Limited | Manufacturing | 2024 |
| Cabra Agencies Limited | Financial services | 2004 |
| CAD by Contract Ltd | Professional & scientific | 2014 |
| Cadew Point Slipway Association Limited | Transport & logistics | 1964 |
| CAFE2U North Down Limited | Hospitality | 2023 |
| Cafollas Ltd | Hospitality | 2016 |
| Cahn Building Services Ltd | Construction | 2024 |
| Cairnduff Property Developments Ltd | Construction | 2022 |
| Cairns Paving and Stone Veneer Ltd | Construction | 2026 |
| Caldwell Convenience Store Limited | Wholesale & retail | 2015 |
| Caleb Evans Limited | Wholesale & retail | 2025 |
| Calebbai AIN Limited | Wholesale & retail | 2025 |
| Call ME Crazy Ltd | Information & communication | 2025 |
| Callacab Ards Limited | Transport & logistics | 2022 |
| Calliopeyan Felixien Limited | Wholesale & retail | 2024 |
| Calmspace Holdings Limited | Information & communication | 2023 |
| Campbell International Trade Limited | Wholesale & retail | 2023 |
| Camphor Digital Limited | Information & communication | 2021 |
| Canavan Painting Contracts Ltd | Construction | 2019 |
| Cancricta Pro Ltd | Wholesale & retail | 2025 |
| Canning Developments Limited | Construction | 2013 |
| Cantley Developments Limited | Construction | 2021 |
| Cape of the Sea Ltd | Wholesale & retail | 2024 |
| Carannac Ltd | Wholesale & retail | 2024 |
| Caravan Blue Limited | Financial services | 2022 |
| Caravan Financial Services Limited | Extraterritorial | 1985 |
| Caricati Tella Ltd | Wholesale & retail | 2024 |
| Carnesure Investments Limited | Real estate | 2018 |
| Carolyn Edgar Homes Ltd | Real estate | 2016 |
| Carrington Terrace Ltd | Real estate | 2023 |
| Carrowdore Autos Ltd | Wholesale & retail | 2022 |
| Carrowdore Shooting Club Ltd | Arts & recreation | 2012 |
| Carrowdore Social and REC Community Interest Company | Hospitality | 2017 |
| Carsons Ices Limited | Hospitality | 2026 |
| Carvale Developments Limited | Construction | 2007 |
| CAS Coachworks Ltd | Wholesale & retail | 2025 |
| Casa Sakura Limited | Real estate | 2025 |
| Cast Residential Ltd | Real estate | 2021 |