| Cosi Interiors Limited | Manufacturing | 2022 |
| Cosi Investments Ltd | Real estate | 2023 |
| Cosi Living (Radlett) Ltd | Manufacturing | 2023 |
| Cosi Living Ltd | Manufacturing | 2017 |
| Cosi Living Slough Ltd | Wholesale & retail | 2025 |
| Cosmetic Surgery Centre Ltd | Health & social care | 2025 |
| Cosmic String Limited | Information & communication | 2015 |
| Cosmin and Partener Design Ltd | Construction | 2024 |
| Cosmin and Partener Ltd | Construction | 2020 |
| Cosmin Drivers Ltd | Administrative & support | 2017 |
| Cosmo Property Holdings Limited | Real estate | 2025 |
| Cosmo Restaurant Group Ltd | Hospitality | 2019 |
| Cosmopolitan Limited | Professional & scientific | 2011 |
| Cosmos Freehold Property Ltd | Real estate | 2025 |
| Cosmos Property Development Ltd | Real estate | 2024 |
| Cosmoslinks Limited | Wholesale & retail | 2023 |
| Costa's Services Ltd | Transport & logistics | 2017 |
| Costcutter Express Slough Limited | Wholesale & retail | 2008 |
| Costless Food and Wine Ltd | Wholesale & retail | 2020 |
| Costy & Co. Logistics Ltd | Transport & logistics | 2016 |
| Costy & Nicoll Transport Ltd | Transport & logistics | 2022 |
| Cosy Corner Lets Ltd | Households | 2025 |
| Cosy Lounge Ltd | Hospitality | 2015 |
| Cosy Properties Investment Limited | Real estate | 2023 |
| Cotob Limited | Administrative & support | 2012 |
| Cotton Productions Limited | Arts & recreation | 2022 |
| Cottonstreet Limited | Real estate | 2022 |
| Coull Consulting Limited | Information & communication | 1999 |
| Counselling and Wellbeing Service Ltd | Health & social care | 2021 |
| Countersteer Limited | Administrative & support | 2008 |
| Counting on IT Ltd | Information & communication | 2026 |
| Country Snugs Ltd | Real estate | 2019 |
| Countrywide Design (Petersfield) Limited | Extraterritorial | 2023 |
| Countrywide Design Holdings Ltd | Extraterritorial | 2011 |
| Couple Bidco Limited | Administrative & support | 2017 |
| Couple Holdco Limited | Administrative & support | 2017 |
| Couple Midco Limited | Administrative & support | 2017 |
| Courdec UK Ltd | Construction | 2010 |
| Courexpress Ltd | Transport & logistics | 2024 |
| Courier App Ltd | Transport & logistics | 2014 |
| Courier Distribution Limited | Transport & logistics | 2019 |
| Courier MAX 24/7 Ltd | Transport & logistics | 2025 |
| Courier Worldwide Limited | Transport & logistics | 2020 |
| Couture Cargo Logistics Limited | Transport & logistics | 2016 |
| Couture Editions Limited | Manufacturing | 2014 |
| Couture Homes Limited | Real estate | 2018 |
| Cowley Builders Ltd | Construction | 2021 |
| COWLEY102 Ltd | Hospitality | 2025 |
| Cowtech IT Services Ltd | Information & communication | 2022 |
| Cozee Living Ltd | Wholesale & retail | 2025 |
| Cozee World Ltd | Wholesale & retail | 2025 |
| Cozy Homes Private Ltd | Real estate | 2021 |
| Cozy Nest Furniture Ltd | Wholesale & retail | 2024 |
| Cozyaura Limited | Wholesale & retail | 2026 |
| CP Berkshire Investment Ltd | Real estate | 2018 |
| Cpas Consulting Limited | Information & communication | 2025 |
| Cpsp Leak Detection Ltd | Construction | 2025 |
| Cpu-World-Uk Ltd | Wholesale & retail | 2017 |
| CQ and Co. Ltd. | Professional & scientific | 2022 |
| CR Cleaning Ltd | Administrative & support | 2018 |
| CR Restaurants Ltd | Hospitality | 2018 |
| Crafthome Solutions Limited | Construction | 2024 |
| Craftovator Ltd | Wholesale & retail | 2016 |
| Craftship Logistic Ltd | Transport & logistics | 2025 |
| Craftygx Ltd | Wholesale & retail | 2022 |
| Craighead Care Limited | Health & social care | 2019 |
| Craigthephysio Ltd | Wholesale & retail | 2026 |
| Crank Investments Ltd | Real estate | 2018 |
| Crank Start Limited | Wholesale & retail | 2020 |
| Cratecrasher Records Ltd | Wholesale & retail | 2019 |
| Crawley Clinic Ltd | Health & social care | 2024 |
| Crazy Grey Productions Ltd | Information & communication | 2019 |
| Crazy Moon Productions Limited | Other services | 2008 |
| CRC Consult Group Limited | Professional & scientific | 2020 |
| CRE8 Investments London Limited | Financial services | 2024 |
| CRE8 Productions Limited | Arts & recreation | 2021 |
| CRE8 Worldwide Limited | Extraterritorial | 2024 |
| Creasta Properties Ltd | Construction | 2025 |
| Create a TEE UK Limited | Wholesale & retail | 2026 |
| Create and Credit Limited | Information & communication | 2026 |
| Create Logic Limited | Health & social care | 2024 |
| Create Wealthy Life Ltd | Professional & scientific | 2019 |
| Creating Cadence Limited | Professional & scientific | 2025 |
| Creating Lifestyles Surbiton Limited | Health & social care | 2012 |
| Creative Background Ltd | Construction | 2018 |
| Creative Beanss Ltd | Information & communication | 2024 |
| Creative Business Change Limited | Professional & scientific | 2010 |
| Creative Design (Structural) Limited | Professional & scientific | 2013 |
| Creative Executions Limited | Arts & recreation | 2004 |
| Creative Limits Ltd | Information & communication | 2017 |
| Creative Trade Ltd | Wholesale & retail | 2023 |
| Creativedarts Ltd | Wholesale & retail | 2012 |
| Creativeurbanrecords Ltd | Information & communication | 2019 |
| Creativibe Limited | Information & communication | 2024 |
| Creator Group Limited | Construction | 2026 |
| Creatorforge Ltd | Professional & scientific | 2026 |
| Creed.C Ltd | Professional & scientific | 2021 |
| Creed.C Management Ltd | Households | 2022 |
| Crescent Bytes IT Solutions Limited | Information & communication | 2026 |
| Crescent Cart Limited | Wholesale & retail | 2025 |