| Care Vending Services Limited | Hospitality | 1998 |
| Careroom Limited | Education | 1998 |
| Carl Falck Associates Limited | Professional & scientific | 2024 |
| Carline Limited | Transport & logistics | 1995 |
| Carlino Collective Limited | Professional & scientific | 2026 |
| Carlton Tractors (Wales) Limited | | 1978 |
| Carmine Finance Limited | Professional & scientific | 2023 |
| Carol Paddison HR Ltd | Administrative & support | 2023 |
| Caroline High Consultancy Ltd. | Professional & scientific | 2021 |
| Carpits Brand Limited | Manufacturing | 2024 |
| Carter Trading Ltd | Hospitality | 2021 |
| Casa Padre Vico Limited | Real estate | 2011 |
| Casa Rica Ltd | Hospitality | 2026 |
| Casalux Group Ltd | Real estate | 2025 |
| Cascade Water Services Ltd | Construction | 2023 |
| Case Matters Group Limited | Financial services | 2024 |
| Casethatnow Limited | Wholesale & retail | 2020 |
| Castle Taxis Limited | Transport & logistics | 2023 |
| Castleshane Consulting Ltd | Professional & scientific | 2022 |
| Cat-Aviation Limited | Manufacturing | 2014 |
| Catalina Consulting Limited | Professional & scientific | 2015 |
| Catalise Limited | Professional & scientific | 2013 |
| Catech. CTS Limited | Manufacturing | 2019 |
| Categorise and Contain Limited | Wholesale & retail | 2022 |
| Catering Workspace Creations Ltd | Professional & scientific | 2024 |
| Cathay Birchen Holdings Limited | Other services | 2019 |
| Catherine Land Design Limited | Information & communication | 2011 |
| Catherine Noden Associates Limited | Professional & scientific | 2013 |
| Cathy Ogilvie Design Limited | Professional & scientific | 2017 |
| Cavaleiro Moraes Ltd. | Real estate | 2017 |
| Cawdex Carpentry Ltd | Construction | 2018 |
| Caws on Tours Ltd | Hospitality | 2024 |
| Cawsburger Limited | Hospitality | 2020 |
| CB Design London Ltd | Wholesale & retail | 2021 |
| CCS Contractors Limited | Construction | 2009 |
| Ccsl Contracts Ltd | Professional & scientific | 2020 |
| Ccsp Holdings Ltd | Real estate | 2020 |
| Ccsp Management Ltd | Real estate | 2020 |
| Cctv and Property Maintenance Ltd | Administrative & support | 2023 |
| Cctv Outlet Limited | Wholesale & retail | 2017 |
| CDF Surgery Matters Limited | Real estate | 2007 |
| CDL Properties (Herts) Ltd | Real estate | 2020 |
| Cedar Place (Kimpton) Management Company Limited | Households | 2015 |
| Celiac Junkey Limited | Hospitality | 2025 |
| Cella Global Limited | Financial services | 2026 |
| Cella Software Limited | Information & communication | 2026 |
| Cellar Group Limited | Extraterritorial | 2020 |
| CEM Emek Ltd | Hospitality | 2017 |
| Center Developments Limited | Construction | 2007 |
| Centime Trading Ltd | Administrative & support | 2021 |
| Centos Digital Ltd | Information & communication | 2025 |
| Centre for Cognitive Behaviour Therapy Ltd | Health & social care | 2007 |
| Centre for Neuroscience Limited | Extraterritorial | 2016 |
| Centre for Rational Emotive Behaviour Therapy Ltd | Health & social care | 2007 |
| Centres of Expertise Ltd | Extraterritorial | 2008 |
| Centrex Print Services Ltd | Other services | 2014 |
| Centrex Support Services Limited | Administrative & support | 2021 |
| Centri Group Ltd | Financial services | 2023 |
| Centroheat Limited | Construction | 2011 |
| Cepheus Properties Limited | Real estate | 1987 |
| Cerenity Healthcare Services Ltd | Health & social care | 2025 |
| Cero Holdings Ltd | Financial services | 2026 |
| Cerulean Productions Limited | Information & communication | 2024 |
| CFB Property Ltd | Real estate | 2025 |
| CG Editorial Limited | Information & communication | 2026 |
| CG Services (Hitchin) Ltd | Manufacturing | 2024 |
| CH Care and Quality Consultancy Limited | Health & social care | 2026 |
| CH Homes Group Ltd | Real estate | 2025 |
| Chace Legal Limited | Professional & scientific | 2011 |
| Chai Stall (Indian Street Food) Limited | Hospitality | 2021 |
| Chalk Stream Learning LLP | | 2023 |
| Challenge Life Club Ltd | Health & social care | 2020 |
| Chamberlins Sols Ltd | Administrative & support | 2020 |
| Chameleon Integrated Project Services Ltd | Professional & scientific | 2008 |
| Chancellers LLP | | 2012 |
| Chandos Holdings Limited | Other services | 2017 |
| Chansol Limited | Manufacturing | 1999 |
| Charles River (Hitchin) Limited | Wholesale & retail | 2019 |
| Charless Ltd | Arts & recreation | 2026 |
| Charlie Puffin Corporate Ventures Limited | Financial services | 2026 |
| Charlie Puffin Digital Ltd | Professional & scientific | 2020 |
| Charlie Puffin Group Limited | Professional & scientific | 2022 |
| Charlie Puffin Limited | Administrative & support | 2019 |
| Charlie Puffin Wealth Limited | Financial services | 2024 |
| Charlie Short Limited | Real estate | 2024 |
| Charlotte and Olivia Limited | Real estate | 2020 |
| Charlotte Dujardin Limited | Arts & recreation | 2013 |
| Charlwood Projects Ltd | Professional & scientific | 2015 |
| Charmit Limited | Hospitality | 2025 |
| Chartfield Consultants Limited | Information & communication | 1999 |
| Chartr Boats Ltd | Transport & logistics | 2025 |
| Chater LEA Plant Ltd | Administrative & support | 2025 |
| Chattel Lease Limited | Professional & scientific | 2004 |
| Check Prop Holdings Limited | Real estate | 2019 |
| Checkley Novillo Ltd | Financial services | 2021 |
| Cheeky Ideas Limited | Arts & recreation | 1991 |
| Cheeky Productions Ltd. | Information & communication | 1990 |
| Cheffinz Ltd | Hospitality | 2023 |
| Chelsea Foods Ltd | Wholesale & retail | 1975 |
| Chem Superweld Private Limited | Manufacturing | 2023 |