| BSD Corporation Ltd | Wholesale & retail | 2024 |
| BSD Supermarket Limited | Wholesale & retail | 2012 |
| BSM Social Care Limited | Health & social care | 2016 |
| Bsupplied Limited | Professional & scientific | 2003 |
| Bubbly Gems Ltd | Education | 2018 |
| Buckley & Wallace Executive Search Ltd | Administrative & support | 2019 |
| Buckley Consultancy Services Limited | Professional & scientific | 2024 |
| Buddy's Cleaning Services Ltd | Administrative & support | 2026 |
| Budget Mattress Company Ltd | Wholesale & retail | 2023 |
| Budget Used Cars Ltd | Wholesale & retail | 2025 |
| Bufd Boards Limited | Wholesale & retail | 2026 |
| Building Design (Northern) Limited | Professional & scientific | 1983 |
| Building Design Northern Developments Limited | Construction | 2022 |
| Building Design Solutions (N.E.) Limited | Professional & scientific | 2011 |
| Building Solutions (Northern) Ltd | Professional & scientific | 2021 |
| Building Top Companies Limited | Administrative & support | 2010 |
| Bulan Burger Joint Ltd | Hospitality | 2023 |
| Bump, Baby & YOU Ltd | Information & communication | 2014 |
| Bumpy Design Limited | Extraterritorial | 2011 |
| Burdon Investments Limited | Real estate | 2019 |
| Burdon LEA Maintenance Limited | Households | 1998 |
| Burger 8 Franchise Ltd | Hospitality | 2024 |
| Burger Blitz Limited | Hospitality | 2024 |
| Burger One Sunderland Ltd | Hospitality | 2019 |
| BURGER8 Limited | Hospitality | 2022 |
| Burgham Park Leisure Limited | Hospitality | 2015 |
| Burgin Enterprise Limited | Real estate | 2017 |
| Buris Supplies Ltd | Wholesale & retail | 2026 |
| Burlace Ltd | Health & social care | 2023 |
| Burma Tresor Ltd | Wholesale & retail | 2025 |
| Bursa Pizza Ltd | Hospitality | 2017 |
| Burton Leisure Limited | Hospitality | 2012 |
| Bushi's Ltd | Hospitality | 2024 |
| Business Energy Pros Ltd | Financial services | 2017 |
| Business Insider Newcastle Limited | Information & communication | 2025 |
| Butcherboybars Limited | Hospitality | 2018 |
| Buur Property Development and Management Services Ltd | Real estate | 2018 |
| BWC UK Ltd | Professional & scientific | 2009 |
| Byjen Academy Ltd | Other services | 2024 |
| Byron Property Management Ltd | Households | 2009 |
| C & F Financial Services Limited | Financial services | 2019 |
| C & G Fabrication and Welding Ltd | Manufacturing | 2024 |
| C & K Consultants Limited | Professional & scientific | 2024 |
| C & R Properties NE Ltd | Real estate | 2023 |
| C Academy Ltd | Education | 2024 |
| C Bestford Limited | Information & communication | 2015 |
| C Briton Wind Solutions Ltd | Professional & scientific | 2026 |
| C C Event Catering Ltd | Wholesale & retail | 2024 |
| C G Owen Engineering Limited | Manufacturing | 2018 |
| C J Waters Wind Energy Ltd | Construction | 2024 |
| C Jarvis Ltd | Manufacturing | 2014 |
| C K Afrique Ltd | Wholesale & retail | 2025 |
| C M Bar Ltd | Hospitality | 2019 |
| C M Indian Ltd | Hospitality | 2019 |
| C MED Spa Ltd | Other services | 2026 |
| C Solutions (NE) Ltd | Construction | 2008 |
| C TAN NE Ltd | Other services | 2025 |
| C&C Layton DMP Limited | Wholesale & retail | 2004 |
| C&F Property Solutions Ltd | Real estate | 2020 |
| C&F UK Solutions Ltd | Administrative & support | 2019 |
| C&G Property Group Ltd | Real estate | 2022 |
| C.A. Richardson Limited | Wholesale & retail | 2005 |
| C.B Gardening Services Sunderland Ltd | Administrative & support | 2026 |
| C.I.A. Training Limited | Information & communication | 1987 |
| C.J Engineering Services Ltd | Construction | 2019 |
| C.M. Electrical & Construction Ltd | Construction | 2011 |
| C.S. Caterers Limited | Administrative & support | 1994 |
| C.W. Partitions & Floors Limited | Manufacturing | 2008 |
| C/A Services ( North East) Ltd | Administrative & support | 2019 |
| C2C Northumberland Ltd | Administrative & support | 2017 |
| C3 Property Group Limited | Real estate | 2026 |
| C3 Roofing Ltd | Construction | 2026 |
| C33 Properties Ltd | Real estate | 2024 |
| Cabinet Colour Switch Ltd | Manufacturing | 2020 |
| Cable Basher Ltd | Construction | 2023 |
| Cable Jointing Services Limited | Construction | 1981 |
| Cactuspizza Ltd | Hospitality | 2025 |
| Cade Access Ltd | Construction | 2024 |
| Cadman and Forrest Ltd | Construction | 2024 |
| Caecias Limited | Information & communication | 2016 |
| Caesar Pizza Ltd | Hospitality | 2025 |
| Caesar Pizza Sunderland Ltd | Hospitality | 2025 |
| Caesar Takeaway Ltd | Hospitality | 2017 |
| CAF Audio Limited | Other services | 2026 |
| Cafe Farah Limited | Hospitality | 2017 |
| CAFE420 Ltd | Hospitality | 2019 |
| Caffe 207 Ltd | Hospitality | 2021 |
| Cairns Parcel Courier Services Limited | Transport & logistics | 2020 |
| Caius Property Limited | Real estate | 2023 |
| Cake Talk Limited | Manufacturing | 2024 |
| Cakebox Sunderland Limited | Wholesale & retail | 2021 |
| Calico Consultancy Services Limited | Administrative & support | 2021 |
| California Foods Ltd | Hospitality | 2024 |
| Callupcompany Ltd | Information & communication | 2019 |
| Calmtoken Limited | Manufacturing | 1986 |
| Calva View Limited | Mining & quarrying | 2024 |
| CAM Construction and Maintenance Ltd | Construction | 2026 |
| CAM Construction Group Ltd | Construction | 2024 |
| Cambridge Leadership Development Limited | Professional & scientific | 2012 |
| Cambuild North East Limited | Construction | 2011 |