| Cells Studio Ltd | Professional & scientific | 2023 |
| CEM Cladding & Roofing Limited | Construction | 2020 |
| Cemre Properties Ltd | Real estate | 2025 |
| Centego Logistics Ltd | Transport & logistics | 2023 |
| Certirep UK Limited | Professional & scientific | 2015 |
| CES M & E Services Limited | Construction | 2013 |
| CES Reactive Limited | Construction | 2015 |
| Ceylon Legacy UK Ltd | Wholesale & retail | 2025 |
| CH Media Associates Limited | Information & communication | 2013 |
| Chalkdene Limited | Real estate | 2006 |
| Chapter House Group Ltd | Real estate | 2024 |
| Chardi Kala Ventures Ltd | Hospitality | 2025 |
| Charles Peter & Co Limited | Professional & scientific | 2002 |
| Charles Peter Accountancy Tutors Limited | Education | 2019 |
| Charles Peter Accountants Limited | Professional & scientific | 2019 |
| Charley Handyman UK Ltd | Construction | 2021 |
| Charlie Pack Finance Limited | Financial services | 2023 |
| Charlotte Grace Real Estate Limited | Extraterritorial | 2014 |
| Charterhouse Investments Group Limited | Real estate | 2009 |
| Charterhouse Whittenbury Associates Limited | Professional & scientific | 2017 |
| Charterhouse Whittenbury Group Limited | Real estate | 2021 |
| Chartwell (UK) Limited | Real estate | 2006 |
| Chase Capital Group Ltd | Financial services | 2026 |
| Chase Electrical Services Ltd | Construction | 2023 |
| Chase Projects Limited | Construction | 1993 |
| Chase Property Portfolio Ltd | Construction | 2026 |
| Chattanooga Ltd | Hospitality | 2025 |
| Cheney Development Ltd | Real estate | 2024 |
| Chengetai Limited | Health & social care | 2010 |
| Cheshunt Carpets and Flooring Ltd | Construction | 2026 |
| Cheshunt Red COW Ltd | Hospitality | 2026 |
| Chewgum Boys Limited | Wholesale & retail | 2022 |
| Chingford Driving School Ltd | Education | 2020 |
| Chivas Technology Ltd | Information & communication | 2020 |
| Chomes Ltd | Real estate | 2026 |
| Chris Morrison Stunts Limited | Information & communication | 2019 |
| Christ Ambassadors Limited | Professional & scientific | 2008 |
| Ciara Drums Ltd | Education | 2023 |
| Cibi Cojo Ltd | Construction | 2023 |
| Cioj Services Limited | Administrative & support | 2025 |
| CIP (Cromwell Road) LLP | | 2019 |
| CIP (Mill Road Development) LLP | | 2016 |
| CIP Orchard Park L2 LLP | | 2019 |
| CIS Rebate Specialist Limited | Professional & scientific | 2017 |
| Citi Locations Ltd | Real estate | 2026 |
| City Fire Expert Ltd | Construction | 2024 |
| City Fish @ Pearce Farm Limited | Wholesale & retail | 2025 |
| City Fish Brokers Limited | Wholesale & retail | 2023 |
| City Fish Holdings Limited | Financial services | 2024 |
| City Reach Properties Limited | Other services | 2016 |
| Cityb Limited | Construction | 2023 |
| Civic Key Properties Ltd | Real estate | 2025 |
| CJ SAX Live Events Ltd | Hospitality | 2019 |
| CJP Media Ltd | Information & communication | 2025 |
| CJS Exteriors Limited | Administrative & support | 1999 |
| CKE Health Care Ltd | Health & social care | 2020 |
| Clanfield Grill Ltd | Hospitality | 2025 |
| Clarc Commercial Fleet Services Limited | Manufacturing | 2025 |
| Clarity Comms Ltd | Information & communication | 2024 |
| Clarity Property Consultants Ltd | Real estate | 2026 |
| Clarity Secure Ltd | Information & communication | 2026 |
| Clarke Estate Agents Ltd | Real estate | 2015 |
| Classiflora Imports Limited | Wholesale & retail | 1987 |
| Classiflora Limited | Extraterritorial | 2025 |
| Claybrook Group Limited | Wholesale & retail | 1991 |
| Clean 4 Today Limited | Water & waste | 2017 |
| Clean Hub and Maintenance Ltd | Administrative & support | 2025 |
| Cleaning & Maintaining Limited | Administrative & support | 2018 |
| Cleankube Ltd | Administrative & support | 2024 |
| Cleanlines Paving Ltd | Administrative & support | 2025 |
| Cleanux Chemicals Ltd | Manufacturing | 2017 |
| Clear Finish Property Maintenance Services Ltd | Administrative & support | 2019 |
| Clear Finish UK Ltd | Administrative & support | 2022 |
| Clear Vista Cleaning Ltd | Administrative & support | 2024 |
| Clementsbury Holdings Ltd | Financial services | 2019 |
| Clementsbury Ross Ltd | Administrative & support | 2019 |
| Clerks Academy UK Limited | Education | 2024 |
| Clerks Associates Consultancy Limited | Education | 2024 |
| Clerks Associates Group Limited | Education | 2024 |
| Clerks Associates Recruitment Limited | Education | 2024 |
| Clerks Associates UK Limited | Education | 2012 |
| Clermont Electrical Engineers & Contractors Ltd | Construction | 2003 |
| CLG Construction Ltd | Construction | 2016 |
| Climate Zone AC Ltd | Construction | 2026 |
| Climate Zone Heating Ltd | Construction | 2026 |
| Cloud Nine Clothing Co Limited | Wholesale & retail | 1994 |
| Clouds (London) Ltd | Wholesale & retail | 2021 |
| Cluster Limited | Real estate | 2006 |
| CM Group Loughton Limited | Real estate | 2018 |
| Cmyk Print Solutions Limited | Manufacturing | 2018 |
| Cmyz Limited | Wholesale & retail | 2020 |
| Coast Tacos Ltd | Hospitality | 2020 |
| Coban UK Properties Limited | Real estate | 2022 |
| Cobbs Investments Limited | Real estate | 2022 |
| Cobmead Management Company Ltd | Real estate | 2018 |
| Coconet TWG Ltd | Professional & scientific | 2023 |
| Cognitrix Limited | Information & communication | 2003 |
| Cohen Griffin Limited | Wholesale & retail | 2015 |
| Coldroomsdirect Ltd | Manufacturing | 2024 |
| Cole Realty Limited | Real estate | 2025 |