| Choyce David Enterprises Limited | Wholesale & retail | 2015 |
| Chris Adams Perfumes Ltd | Wholesale & retail | 2009 |
| Chris Top Services Ltd | Administrative & support | 2025 |
| Christ Centrl Ltd | Information & communication | 2026 |
| Chroniclers Ltd | Administrative & support | 2026 |
| Chuan FU Xiao CHU Ltd | Hospitality | 2025 |
| Chug Ltd | Manufacturing | 2025 |
| Chunky Junk Ltd | Water & waste | 2018 |
| Church Group Limited | Manufacturing | 2023 |
| Churchill PIR Limited | Agriculture & fishing | 2019 |
| Churchill Transfers and Tours Ltd | Transport & logistics | 2018 |
| Cinedream UK Limited | Information & communication | 2019 |
| Cinematic Productions Ltd | Information & communication | 2023 |
| Cintrinsic IT Solutions Limited | Information & communication | 2013 |
| Cipher Networks Ltd | Information & communication | 2013 |
| Citadel Enterprises Limited | Real estate | 2020 |
| Citi Housing Marketing Global Ltd | Professional & scientific | 2025 |
| Citispot Ltd | Real estate | 2024 |
| Citrus News & Wine Ltd | Wholesale & retail | 2020 |
| City Accountants and Tax Practitioners Ltd | Professional & scientific | 2019 |
| City Elegance Limited | Administrative & support | 2022 |
| City Homes Investments Limited | Real estate | 2024 |
| City Place Gatwick Management Company Limited | Real estate | 1997 |
| City Pro Transport Car Ltd | Transport & logistics | 2020 |
| City Sky Building Ltd | Construction | 2018 |
| City West Property Investments Ltd | Real estate | 2019 |
| Citylink Taxi Limited | Transport & logistics | 2026 |
| Citysoft Technologies Ltd | Information & communication | 2011 |
| Citywest Estate Agents Limited | Hospitality | 2017 |
| Citywide Auto Ltd | Wholesale & retail | 2026 |
| Citywide Care Agency Ltd | Other services | 2017 |
| Civstru Architects & Engineers Ltd | Construction | 2025 |
| CK Grill Limited | Hospitality | 2024 |
| CK Staffing UK Limited | Administrative & support | 2022 |
| Ckmprs Limited | Professional & scientific | 2022 |
| CL Law Corporate Limited | Professional & scientific | 2016 |
| CL Law LLP | | 2009 |
| Clairx Limited | Information & communication | 2026 |
| Clancy Services Limited | Information & communication | 2026 |
| Clarence Simar Group Ltd | Manufacturing | 2025 |
| Clarimond Ltd | Wholesale & retail | 2025 |
| Claritypro Associates Ltd | Professional & scientific | 2021 |
| Class 1 Personnel (Airside) Ltd | Administrative & support | 2021 |
| Class 1 Personnel (Aviation) Ltd | Administrative & support | 2014 |
| Class 1 Personnel Limited | Administrative & support | 1999 |
| Class Mark Ltd | Wholesale & retail | 2022 |
| CLASS1 Windows and Doors Limited | Construction | 2016 |
| Classic Barber Ltd | Other services | 2025 |
| Classic Signature Limited | Wholesale & retail | 2023 |
| Classy Builders Ltd | Construction | 2025 |
| Classy Cruise Limited | Transport & logistics | 2025 |
| Clavius Consultants Ltd | Information & communication | 2019 |
| CLD Finance Ltd | Professional & scientific | 2021 |
| Clean Angel Limited | Wholesale & retail | 2025 |
| Clean Home London Ltd | Other services | 2017 |
| Clean My DPF Ltd | Manufacturing | 2026 |
| Cleaning and Maintenance Solutions Ltd | Administrative & support | 2019 |
| Cleans 4 U Limited | Administrative & support | 2025 |
| Cleanzat Ltd | Construction | 2025 |
| Clear Path Driving School Ltd | Education | 2025 |
| Clear Star Limited | Real estate | 2019 |
| Clearscan Environmental Ltd | Professional & scientific | 2024 |
| Clearview Homes Group Limited | Construction | 2021 |
| Clearway Courier Services Ltd | Transport & logistics | 2026 |
| Clearway Movers Ltd | Transport & logistics | 2025 |
| Clements Realty Limited | Real estate | 2021 |
| Cleto Auto Repair Ltd | Wholesale & retail | 2025 |
| Clevercasa Ltd | Wholesale & retail | 2024 |
| Click Haulage Express Ltd | Transport & logistics | 2014 |
| Click Technologies Limited | Information & communication | 2015 |
| Clickkart Hub Limited | Wholesale & retail | 2025 |
| Clik N Buy Ltd | Hospitality | 2019 |
| Climaire Prestige Ltd | Construction | 2025 |
| Climery Ltd | Administrative & support | 2025 |
| Climpland Limited | Households | 1982 |
| Clip of Fayyaz PVT Ltd | Administrative & support | 2016 |
| Clipboard Films Ltd | Information & communication | 2026 |
| Clipman Ltd | Wholesale & retail | 2025 |
| Cloisters Business Management Limited | Real estate | 2026 |
| Closetory Ltd | Wholesale & retail | 2026 |
| Cloud Architectures Ltd | Information & communication | 2018 |
| Cloud Export Services Limited | Administrative & support | 2020 |
| Cloud Investments Ltd | Real estate | 2025 |
| Cloude IT Limited | Information & communication | 2019 |
| Cloudice Technology Solutions Ltd | Information & communication | 2023 |
| Club Pure Ltd | Wholesale & retail | 2025 |
| Clubclass Ltd | Transport & logistics | 2025 |
| CLW Luxline Limited | Administrative & support | 2025 |
| CLX Europe Media Solution Ltd | Manufacturing | 1988 |
| CM Multiservices Limited | Construction | 2020 |
| CM Phones & Foods Limited | Wholesale & retail | 2016 |
| Cmap Services Ltd | Wholesale & retail | 2017 |
| CMP Building Construction Ltd | Construction | 2022 |
| CMP London Ltd | Real estate | 2020 |
| CMS Squared Limited | Professional & scientific | 2022 |
| Cnblink Limited | Information & communication | 2012 |
| CNC Machine Services Ltd | Manufacturing | 2023 |
| Cndeducationservices Ltd | Education | 2023 |
| COB Recruitment Ltd | Administrative & support | 2019 |
| Cobalt Ground Solutions Limited | Transport & logistics | 1995 |