| BFD BEE Shop Ltd | Wholesale & retail | 2010 |
| Bfte Solutions Ltd | Wholesale & retail | 2014 |
| BH & B Limited | Real estate | 2016 |
| Big Balance Theory Limited | Administrative & support | 2021 |
| Big Red Rigs Ltd | Transport & logistics | 2021 |
| Bing Building Ltd | Construction | 2018 |
| Biodiversity Limited | Professional & scientific | 1989 |
| Bitwise Developments Ltd | Education | 2023 |
| Bkjg Property Ltd | Real estate | 2025 |
| Black Honey Tattoos Limited | Other services | 2024 |
| Blestium Financial Services Ltd. | Financial services | 2020 |
| Blockshare Resident Management Limited | Households | 1987 |
| Blooms and Rooms Ltd | Administrative & support | 2021 |
| Blossom Group Limited | Information & communication | 1999 |
| Blue Balloon Property Holdings Ltd | Real estate | 2021 |
| Bluebird Marketing & Communications Limited | Professional & scientific | 2024 |
| Blueprint Digital Media Limited | Information & communication | 2015 |
| Bluestone Construction Limited | Construction | 2021 |
| BMH Services Limited | Other services | 2016 |
| BNR Agency Ltd | Health & social care | 2014 |
| Border Bookkeeping Services Ltd | Professional & scientific | 2019 |
| Border Surfacing Plant & Property Ltd | Administrative & support | 2012 |
| Borderbuild Construction Ltd | Extraterritorial | 2023 |
| Borderlands Outdoor Instruction Ltd | Education | 2019 |
| Boulton Electricals Limited | Construction | 2025 |
| Bourton Vale Equestrian Centre Ltd | Education | 2024 |
| BOW Urban Development Ltd | Construction | 2025 |
| Bowers Parks Limited | Real estate | 2018 |
| Bowland Fabrics Limited | Wholesale & retail | 2013 |
| Brad Jarvis Ltd | Transport & logistics | 2015 |
| Brandfish Limited | Professional & scientific | 2006 |
| Braymeare Property Group Limited | Real estate | 2023 |
| Breakthrough Mortgage & Financial Services Limited | Financial services | 2014 |
| Bridges Centre | Arts & recreation | 1999 |
| Bris Electrical Ltd | Construction | 2020 |
| Bristol Business College Ltd | Education | 2007 |
| Bristol Drylining South West Limited | Construction | 2018 |
| Brocks Property Ltd | Real estate | 2025 |
| Brogan Business Development Services Limited | Professional & scientific | 2009 |
| Brooke Estate Management Ltd | Other services | 2012 |
| Brown Car Films Limited | Professional & scientific | 2004 |
| Brucey and Family Limited | Real estate | 2025 |
| Buckholt Bryngaer CIC | Other services | 2023 |
| Buckingham Gardens Limited | Administrative & support | 2024 |
| Buckland Dartford Limited | Real estate | 2007 |
| Buildabillity Ltd | Construction | 2020 |
| Building Services Solutions (Western) Limited | Professional & scientific | 1998 |
| Buildupp Ltd | Information & communication | 2016 |
| Burnett Commercial Ltd | Professional & scientific | 2015 |
| Burnham Phillips Ltd | Professional & scientific | 2003 |
| Burtt-Jones & Brewer Limited | Professional & scientific | 2018 |
| Bush House Osteopathic Practice Limited | Health & social care | 2003 |
| Bushes Farm Limited | Financial services | 2016 |
| Business and Technical Languages Limited | Education | 2012 |
| Busy Bodies Playgroup Ltd | Education | 2019 |
| BWC Groundworks Ltd | Construction | 2016 |
| C & N Facilities Limited | Construction | 2018 |
| C & N Holdings Limited | Professional & scientific | 2001 |
| C 3 Property Limited | Hospitality | 2000 |
| C G Edwards Construction Ltd | Construction | 2025 |
| C H Stokes Tree Surgery and Fencing Ltd | Agriculture & fishing | 2017 |
| C L Holme Limited | Professional & scientific | 2017 |
| C&N Birchgrove Ltd | Health & social care | 2025 |
| C&N Cardiff and Vale Ltd | Health & social care | 2026 |
| C&N Dental Ltd | Health & social care | 2019 |
| C&N Freehold Ltd | Real estate | 2023 |
| C&N Smile Ltd | Health & social care | 2023 |
| C.R. Gough Electrical Services Limited | Construction | 2024 |
| C3 Communications Ltd | Professional & scientific | 2023 |
| C3 Services Consulting Ltd | Professional & scientific | 2024 |
| Caenog Holdings LLP | | 2022 |
| Calahans Developments Limited | Construction | 2012 |
| Callisto Style LLP | | 2015 |
| Callow Woods Limited | Agriculture & fishing | 1997 |
| Cambridge Health Sciences Limited | Manufacturing | 2019 |
| Cameron Leigh Limited | Professional & scientific | 2011 |
| Campfire Convention Ltd | Wholesale & retail | 2014 |
| Canning Swann Consult Ltd | Professional & scientific | 2025 |
| Cardiff Exchange and Office Company Limited(The) | Construction | 1883 |
| Carilo Limited | Professional & scientific | 2015 |
| Carlos Construction & Management Ltd | Construction | 2025 |
| Carte Blanche Wines Limited | Wholesale & retail | 2009 |
| Casework Support Ltd. | Administrative & support | 2021 |
| Casl Management Development Ltd | Professional & scientific | 2007 |
| Cathays Cottage Company Limited(The) | Construction | 1885 |
| CB Construction Services Limited | Wholesale & retail | 2007 |
| CCR Consultancy Ltd | Professional & scientific | 2024 |
| Celliwig Limited | Transport & logistics | 2013 |
| Celtic Care (Monmouth) Limited | Health & social care | 2024 |
| Celtic Hire Ltd | Construction | 2012 |
| Celtic Pathways Limited | Real estate | 2021 |
| Celyn Childcare C.I.C. | Health & social care | 2024 |
| Central Civils & Groundworks Limited | Construction | 2022 |
| Certraq Ltd | Financial services | 2018 |
| Cetl Ltd | Agriculture & fishing | 2021 |
| Cfsgbi Ltd | Health & social care | 2001 |
| CH Property Maintenance Ltd | Households | 2017 |
| Chainwave Limited | Information & communication | 2020 |
| Charlie Lester Limited | Arts & recreation | 2025 |
| Charliemax Music Productions Limited | Arts & recreation | 2019 |