| Chem UK Expo Limited | Administrative & support | 2015 |
| Chemical Relations Limited | Professional & scientific | 2008 |
| Chennai Biryani Group Ltd | Hospitality | 2025 |
| Chepstow Business Park Limited | Real estate | 2025 |
| Cherished Minds EP Service Limited | Education | 2023 |
| Cheron Trading Limited | Construction | 2020 |
| Chestnuts TW1 Limited | Education | 2018 |
| Chevallier Coaching and Consulting Ltd | Professional & scientific | 2022 |
| Chevonion Limited | Administrative & support | 2014 |
| Chez Stones Ltd | Wholesale & retail | 2022 |
| CHG Consultancy Limited | Professional & scientific | 2010 |
| Chic Showdown Ltd | Wholesale & retail | 2024 |
| Chicken City Ltd | Hospitality | 2018 |
| Child Mental Health Clinic Limited | Health & social care | 2017 |
| Chillbox UK Ltd | Extraterritorial | 2012 |
| Chilvers Close Management Limited | Households | 2000 |
| Chiswick Pilates and Physio Ltd | Other services | 2021 |
| Chivale Limited | Real estate | 2025 |
| Chloe Gibb Coaching Limited | Professional & scientific | 2016 |
| Chloe Grindle Creative Limited | Professional & scientific | 2025 |
| Chris Carpentry KP Limited | Manufacturing | 2015 |
| Chris Zach Ltd | Health & social care | 2026 |
| Christian Lambelin Ltd | Administrative & support | 2008 |
| Christopher Harden Limited | Professional & scientific | 2014 |
| Christopher Tredway Architects Ltd | Professional & scientific | 2018 |
| Christopher Wright & Co LLP | | 2012 |
| Chrysalis CX Ltd | Professional & scientific | 2022 |
| Chungs 316 Ltd | Hospitality | 2023 |
| Cine Lighting Control Ltd | Arts & recreation | 2019 |
| Circe Beauty Studio Limited | Other services | 2024 |
| Citec International Limited | Administrative & support | 2004 |
| City of London Property Investment Corporation Limited | Real estate | 2014 |
| CKC Strategic Communications Ltd | Professional & scientific | 2008 |
| Claire Arnott Consulting Limited | Professional & scientific | 2025 |
| Claire Barrett Real Estate Limited | Real estate | 2025 |
| Claire Presents Limited | Extraterritorial | 2024 |
| Clairvoyance Services Limited | Professional & scientific | 2016 |
| Claremont Services Ltd | Administrative & support | 2022 |
| Clarendon Home Care Limited | Health & social care | 2001 |
| Claretuam Consulting Limited | Administrative & support | 2016 |
| Clarity Group Advisors Limited | Professional & scientific | 2024 |
| Clarityse Ltd | Professional & scientific | 2011 |
| Classic Pizzaria Ltd | Hospitality | 2025 |
| Claw Properties Ltd | Real estate | 2024 |
| Clean Concepts Limited | Administrative & support | 2002 |
| Clean Motion Limited | Administrative & support | 2025 |
| Clean Spaces - Property Services Ltd | Real estate | 2024 |
| Cleanin' Club Ltd | Other services | 2025 |
| Clear Bubble Solutions Ltd | Other services | 2019 |
| Clearwin Automation Limited | Information & communication | 2025 |
| Cleary Holdings Limited | Financial services | 2022 |
| Click Group IRL Ltd | Wholesale & retail | 2018 |
| Clicked Lens Limited | Administrative & support | 2024 |
| Clifden Court Management (Twickenham) Limited | Real estate | 1968 |
| Climatron Ltd | Real estate | 2021 |
| Clinging IVY Homes Ltd | Real estate | 2017 |
| Clive Ainsworth Carpentry Ltd. | Construction | 2015 |
| Clive Chapman Architects Ltd | Professional & scientific | 2023 |
| Clockwork Orchard Ltd | Information & communication | 2025 |
| Closed Loop Environmental Solutions UK Limited | Administrative & support | 2007 |
| Cloth and Clay Limited | Manufacturing | 2020 |
| Cloud Rides Ltd | Transport & logistics | 2026 |
| Clovenstone Consulting Limited | Professional & scientific | 2020 |
| Cloverdawn Property Management Limited | Real estate | 2004 |
| Clowders Limited | Wholesale & retail | 2012 |
| CLT Consulting Limited | Professional & scientific | 2025 |
| CLV Marketing Ltd | Information & communication | 2025 |
| CM Home Services Limited | Real estate | 2024 |
| CMG Research Limited | Information & communication | 2007 |
| CMJ Builders & Construction Limited | Construction | 2014 |
| Cnet Consultancy Ltd | Information & communication | 2011 |
| CNS Aesthetics Ltd | Other services | 2020 |
| Co-Opts Limited | Information & communication | 2020 |
| Coast Road Systems Limited | Information & communication | 2014 |
| Coax Connectors Limited | Wholesale & retail | 2001 |
| Coax Direct Ltd | Manufacturing | 2015 |
| Coburns Party Wall Ltd | Professional & scientific | 2016 |
| Cochin Restaurant Limited | Hospitality | 2018 |
| Codefuse Technology Limited | Information & communication | 2013 |
| Codelity Ltd | Information & communication | 2018 |
| Codex Informatics Limited | Professional & scientific | 2003 |
| Codexo Limited | Administrative & support | 2025 |
| Coffee Knightsbridge Ltd | Other services | 2023 |
| Coffee Mill Deli Cafe Limited | Hospitality | 2018 |
| Cole Park Construction Ltd | Hospitality | 2012 |
| Collaboration Coach Limited | Information & communication | 2017 |
| Colombus Limited | Real estate | 2024 |
| Colonial PUB Company Limited | Hospitality | 2014 |
| Colum & Rowe Ltd | Professional & scientific | 2023 |
| Comexwise Ltd | Information & communication | 2026 |
| Commercial DRY Cleaning Limited | Administrative & support | 2016 |
| Commercial Utility Limited | Administrative & support | 2017 |
| Commercial X Limited | Professional & scientific | 2024 |
| Companies in Motion Ltd | Professional & scientific | 2008 |
| Companions in Joy Limited | Real estate | 2022 |
| Compass Advisors Limited | Real estate | 2025 |
| Complete Hi-Fi Sound & Vision Limited | Extraterritorial | 2014 |
| Computers Help Limited | Information & communication | 2008 |
| Coningsby Estates Limited | Real estate | 2026 |
| Conleth Ltd | Real estate | 2015 |