| Brightwave Ventures Limited | Real estate | 2023 |
| Brindlex LLP | | 2025 |
| Bring Your Own Bartender Ltd | Hospitality | 2025 |
| British Georgian Association | Other services | 2011 |
| Brixsom Ltd | Mining & quarrying | 2019 |
| BRP & Associates Ltd | Construction | 2008 |
| Bryan Traders Ltd | Other services | 2025 |
| BSE Construction Ltd | Construction | 2015 |
| Btransforms Limited | Information & communication | 2023 |
| Buddy Moon Ltd | Professional & scientific | 2023 |
| Budgefrownie Ltd | Information & communication | 2026 |
| Build Master Construction Ltd | Manufacturing | 2016 |
| Building Refurbishment Solutions Ltd | Construction | 2025 |
| Buildwise Construction Limited | Construction | 2008 |
| Bujrum Limited | Hospitality | 2024 |
| Bulgari Developments Limited | Construction | 2006 |
| Bulls IT Services Ltd | Information & communication | 2019 |
| Bullseye Interiors Ltd | Construction | 2016 |
| Burcoo Ltd | Transport & logistics | 2019 |
| Bush Boake Allen Australia Limited | | 1994 |
| BUX Estate Ltd | Real estate | 2021 |
| BUZ Recruitment Limited | Administrative & support | 2026 |
| BY Maev Limited | Wholesale & retail | 2020 |
| Byhasanat Ltd | Other services | 2020 |
| C and L Collections Ltd | Extraterritorial | 2015 |
| C S (Norwich) Limited | Information & communication | 2005 |
| C&N Constructions Limited | Construction | 2013 |
| C&R Recovery Clinic Limited | Health & social care | 2025 |
| C-Horse Games Limited | Information & communication | 2021 |
| C. GUO Investments Ltd | Real estate | 2026 |
| C.P.C. UK Limited | Construction | 1998 |
| C55 Productions Limited | Wholesale & retail | 2019 |
| C8PES Limited | Real estate | 2017 |
| Cadogan Mcqueen Limited | Real estate | 2015 |
| Cafe Sashka Limited | Hospitality | 2025 |
| CAL & Co Group Ltd | Professional & scientific | 2024 |
| Cale Harrison Ltd | Professional & scientific | 2024 |
| Calf and Hoof Ltd | Hospitality | 2026 |
| Caliber Engineering Services UK Ltd | Construction | 2021 |
| Caligo Group Ltd | Financial services | 2024 |
| Caligo London Ltd | Wholesale & retail | 2024 |
| Call ME a Plumber Ltd | Construction | 2024 |
| Calling Bell UK Limited | Administrative & support | 2021 |
| Cameleye Ltd | Professional & scientific | 2021 |
| Canal Crest Limited | Households | 2012 |
| Cancri Jewellers Ltd | Wholesale & retail | 2025 |
| Capacious Consulting Limited | Professional & scientific | 2021 |
| Capacity House Services Ltd | Professional & scientific | 2026 |
| Capital Coatings Group Ltd | Wholesale & retail | 2026 |
| Capital Rugs Limited | Wholesale & retail | 2013 |
| Capital Spray Ltd | Administrative & support | 2016 |
| Capital Trading Partners LLP | | 2023 |
| Capitalix Consultancy (UK) Ltd | Professional & scientific | 2013 |
| Captivate Ltd | Wholesale & retail | 2023 |
| Care Clue Services Limited | Health & social care | 2023 |
| Care Quest Group Ltd | Hospitality | 2024 |
| CARE2CARE Children's Home Ltd | Health & social care | 2018 |
| Career Oasis Limited | Information & communication | 2013 |
| Carermart Limited | Professional & scientific | 2023 |
| Casa Coco Ltd | Real estate | 2025 |
| Casa DI Santo Limited | Manufacturing | 2016 |
| Cassys Consulting Ltd | Professional & scientific | 2017 |
| Castlehaven Holdings Limited | Real estate | 2005 |
| Castlehaven Properties Limited | Professional & scientific | 2011 |
| Catarsis Solutions Ltd | Administrative & support | 2022 |
| Catarsis Solutions Pro Ltd | Administrative & support | 2024 |
| Cave Grill Bar Ltd | Hospitality | 2026 |
| CB Coaching Consulting LLP | | 2023 |
| Cbkfashyto & Co Ltd | Health & social care | 2010 |
| CC Design Limited | Professional & scientific | 2012 |
| Ccha Holdings Ltd | Real estate | 2022 |
| Ccjm Consulting Limited | Professional & scientific | 2019 |
| CE Trade Limited | Transport & logistics | 2026 |
| Cedars Corporate Services Limited | Extraterritorial | 2013 |
| Celestial Reality Ltd | Information & communication | 2018 |
| Centertel Ltd | Information & communication | 2018 |
| Central Chief Kitchen Limited | Manufacturing | 2023 |
| Ceremonies by Eunice Ltd | Other services | 2026 |
| Cextech Cheltenham Limited | Other services | 2008 |
| Cextech Slough Limited | Other services | 2009 |
| CG Green Solutions Ltd | Information & communication | 2020 |
| Chaarco Ltd | Wholesale & retail | 2013 |
| Champ Systems Limited | Information & communication | 2012 |
| Champion Trading Limited | Wholesale & retail | 2023 |
| Champions Martial Arts CIC | Arts & recreation | 2025 |
| Charlie Books Ltd | Wholesale & retail | 2020 |
| Charly Publishing Limited | Information & communication | 1981 |
| Charly Records Limited | Information & communication | 2022 |
| Chau & Co. Realty Ltd | Real estate | 2025 |
| Cheers & Gone Ltd | Information & communication | 2019 |
| Cheerscheers Limited | Wholesale & retail | 2011 |
| Cherrylazar Limited | Arts & recreation | 2023 |
| Chetana Infotech Limited | Information & communication | 2020 |
| Chez Building Services Limited | Construction | 2016 |
| Chez Logos Ltd | Other services | 2022 |
| Chibici Ltd | Information & communication | 2023 |
| Chic Diamond Atelier Ltd | Wholesale & retail | 2025 |
| CHIC4U Ltd | Wholesale & retail | 2025 |
| Children & Young People Services Ltd | Health & social care | 2023 |
| Children & Young People's Services CIC | Wholesale & retail | 2025 |