| Byte Nest Solutions Ltd | Wholesale & retail | 2025 |
| Bäan Fabrics Ltd | Wholesale & retail | 2025 |
| C & D (Marchmont) Limited | Construction | 2007 |
| C & Z Elze LLP | | 2004 |
| C and D Pubs Limited | Hospitality | 2026 |
| C and S Tyres Limited | Wholesale & retail | 1998 |
| C C B (UK) Limited | Professional & scientific | 2002 |
| C C P M Limited | Administrative & support | 1997 |
| C Haddedou Holdings Ltd | Professional & scientific | 2020 |
| C Laud TM Limited | Construction | 2026 |
| C R Brown Electrical Limited | Construction | 2017 |
| C.W. Russell Ltd | Administrative & support | 2006 |
| C.W.Russell (Holdings) Ltd | Financial services | 2020 |
| Cabana Sports Ltd | Arts & recreation | 2024 |
| Cacique Capital Limited | Professional & scientific | 2009 |
| CAD4DESIGNERS Ltd | Professional & scientific | 2022 |
| Cafe Nano Ltd | Hospitality | 2022 |
| Cafe Salute Ltd | Wholesale & retail | 2023 |
| Cafe Sisi on the Park Ltd | Hospitality | 2014 |
| Cafe Tinto Limited | Hospitality | 2024 |
| Caffe Mamma Limited | Hospitality | 2015 |
| Caffe Millar Limited | Real estate | 2022 |
| CAH Sailing Ltd | Arts & recreation | 2013 |
| CAJ Estates Limited | Real estate | 2026 |
| Cakes by Chlobo Ltd | Manufacturing | 2012 |
| Calanca Ltd | Professional & scientific | 2019 |
| Calendar Competitons Limited | Administrative & support | 2025 |
| Call Control Technologies Limited | Manufacturing | 2012 |
| Callbean Limited | Financial services | 2018 |
| Calm Wellbeing Ltd | Health & social care | 2024 |
| Calton Group Ltd | Construction | 2018 |
| Calva Consulting Limited | Professional & scientific | 2017 |
| Calvert & Co Construction Limited | Construction | 2026 |
| Calvert & Jenkinson Limited | Construction | 2008 |
| Calvert PMC Ltd | Professional & scientific | 2021 |
| Cambrian Advisory Corporation Limited | Professional & scientific | 1982 |
| Cambrian Community Centre | Arts & recreation | 2012 |
| Cambrian Gate Research and Technologies Ltd | Professional & scientific | 2023 |
| Cambrian Holdings International Limited | Information & communication | 2021 |
| Campaign Nine Limited | Professional & scientific | 2012 |
| Camperio Legal & Fiduciary Services PLC | | 2023 |
| Canberra Place (UK) Limited | Professional & scientific | 2011 |
| Canberra Place Management Company Limited | Extraterritorial | 2004 |
| Candid Convo Ltd | Information & communication | 2021 |
| Candra Lighting Limited | Professional & scientific | 2014 |
| Cannaskope Ltd | Professional & scientific | 2020 |
| Cannon Mechanical Services Limited | Construction | 2006 |
| Cannon Property Investments Limited | Financial services | 2025 |
| Canopy KEW Limited | Wholesale & retail | 2022 |
| Canopy Vision Limited | Professional & scientific | 2024 |
| Cantell & Co Limited | Real estate | 2012 |
| Cantell Partnership Limited | Real estate | 2016 |
| Canterbury Law Ltd | Real estate | 2022 |
| Capital Block Maintenance Ltd | Construction | 2020 |
| Capital Block Management Ltd | Real estate | 2020 |
| Capital Block Plumbing Ltd | Construction | 2021 |
| Capital Credit Ratings Ltd | Information & communication | 2022 |
| Capital Facade Management Ltd | Professional & scientific | 2020 |
| Capsol Acquisitions PLC | Financial services | 2023 |
| Capsol Finance Limited | Financial services | 2021 |
| Capsol Investments Ltd | Financial services | 2012 |
| Capstone Consultancy Ltd | Professional & scientific | 2012 |
| Capstone Health Consultants Limited | Professional & scientific | 2015 |
| Captain Barney's Limited | Hospitality | 2012 |
| Capwell Limited | Construction | 2005 |
| Carbonite Challenge Coins Ltd | Professional & scientific | 2025 |
| Carbonite Clean Ltd | Administrative & support | 2011 |
| Carbonite Protect Ltd | Administrative & support | 2022 |
| Carbonite Screening Ltd | Administrative & support | 2025 |
| Carbonite Traffic Solutions Ltd | Administrative & support | 2020 |
| Cardigan House Limited | Real estate | 1994 |
| Care Nightingales Ltd | Extraterritorial | 2022 |
| Carebeans Limited | Health & social care | 2019 |
| Carebrain Limited | Health & social care | 2024 |
| Caribbean Expressions Limited | Extraterritorial | 1997 |
| Carkin Moor Farm Eggs Limited | Agriculture & fishing | 2018 |
| Carl Graham Interiors Ltd | Professional & scientific | 2016 |
| Carlo's Miniatures Ltd | Arts & recreation | 2021 |
| Carlucci Hairdressing Limited | Wholesale & retail | 2008 |
| Carmichael Brown Heating Ltd | Professional & scientific | 2016 |
| Caroline Gibson Limited | Administrative & support | 2025 |
| Carone Asset Holdings Ltd | Real estate | 2025 |
| Carp & Tree Ltd | Construction | 2015 |
| Carpenter Keen LLP | | 2006 |
| Carr & Company (London) Limited | Professional & scientific | 2015 |
| Carthage Medical Ltd | Health & social care | 2011 |
| Casa Latina Imports Ltd | Wholesale & retail | 2023 |
| Caseneuve Limited | Information & communication | 2020 |
| Casp Care Limited | Health & social care | 2024 |
| Castle Fisheries Richmond Ltd | Hospitality | 2019 |
| Castle Fleet Ltd | Wholesale & retail | 2025 |
| Castle Stone Property Limited | Real estate | 2016 |
| CASTLECOTTAGE2 Ltd | Hospitality | 2019 |
| Catalytic Knowhow Ltd | Real estate | 2015 |
| Catalyzd Limited | Professional & scientific | 2024 |
| Cattaneo Menswear Limited | Wholesale & retail | 2014 |
| Catterick Property Developments Limited | Real estate | 1983 |
| Catterick Property Holdings Limited | Financial services | 2006 |
| Catterick Racecourse Company Limited(The) | Arts & recreation | 1923 |
| Catterick Service Station Ltd. | Wholesale & retail | 1998 |