| Clean Combustion Ltd | Professional & scientific | 2020 |
| Clean CUT Contracts Ltd | Construction | 2022 |
| Clean Environment Holdings UK Ltd | Financial services | 2023 |
| Clear CUT Ltd | Financial services | 2023 |
| Clear Design Consultancy Limited | Information & communication | 2002 |
| Clearbrew Essex Ltd | Administrative & support | 2019 |
| Cleartone Communications U.K. Limited | Information & communication | 2006 |
| Cleaverbay Limited | Wholesale & retail | 2003 |
| Clever Olive Limited | Financial services | 2026 |
| Cleverwoof Limited | Manufacturing | 2015 |
| Click Finder Limited | Professional & scientific | 2024 |
| Click International Ltd | Wholesale & retail | 2025 |
| Cliffe Rural Limited | Real estate | 2026 |
| Clifford Gardens (Skipton) Management Company Limited | Real estate | 2023 |
| Clifton Court (Avenue) Management Company Limited | Households | 2003 |
| Climatemp Limited | Construction | 2016 |
| Clinovo Health Ltd | Information & communication | 2025 |
| Clip Strips Ltd | Professional & scientific | 2024 |
| Clip-Lok Simpak (GBE) UK Limited | Administrative & support | 2004 |
| Clive Cadman Limited | Agriculture & fishing | 2003 |
| Clive Pugh Funeral Directors Limited | Professional & scientific | 2004 |
| Clivewood Investments Ltd | Real estate | 2019 |
| Clmw Limited | Professional & scientific | 2018 |
| Clock Walk (Flats) Management Limited | Households | 1988 |
| Clockwork Organisation Limited | Professional & scientific | 1983 |
| Clorley Holdings Limited | Real estate | 2020 |
| Cloud 9 Horizons Ltd | Wholesale & retail | 2025 |
| Cloud Control Solutions Limited | Administrative & support | 2014 |
| Cloud Global Services Limited | Professional & scientific | 2021 |
| Cloudnostics Ltd | Information & communication | 2021 |
| Clun Forest Sheep Breeders Society Limited(The) | Agriculture & fishing | 1947 |
| CM Lifestyle LLP | | 2019 |
| CMC Manufacturing Ltd | Manufacturing | 2018 |
| CMC Retail Ltd | Wholesale & retail | 2016 |
| CML Express Delivery Limited | Transport & logistics | 2017 |
| Cmle Ltd | Professional & scientific | 2018 |
| CMS JAW Limited | Construction | 1977 |
| CMS Tennis Limited | Arts & recreation | 2026 |
| CMV Holdings Limited | Administrative & support | 2024 |
| CNL Fuels Limited | Wholesale & retail | 2023 |
| CNS Physio Ltd | Health & social care | 2023 |
| Coach Kayleigh Limited | Arts & recreation | 2024 |
| Cobholm Business Park Limited | Real estate | 2023 |
| Cochrane Coaching and Development Ltd | Professional & scientific | 2012 |
| Coco Marketing Limited | Financial services | 2022 |
| Cocothom Consulting Ltd | Professional & scientific | 2019 |
| Codebreak Group Limited | Administrative & support | 2015 |
| Coed Castell Management Company Limited | Households | 2005 |
| Coffee Plus One Limited | Hospitality | 2022 |
| Cogent Consultancy Limited | Professional & scientific | 2009 |
| Cogitor Limited | Information & communication | 2017 |
| Cognitive Designs Limited | Wholesale & retail | 2026 |
| Cognoscentus Limited | Professional & scientific | 2017 |
| Coin & Medal Fairs Limited | Wholesale & retail | 2005 |
| Colander Technology Limited | Wholesale & retail | 2017 |
| Cold Mercury Ltd | Professional & scientific | 2024 |
| Cole Hall Mews Management Company Limited | Hospitality | 2015 |
| Coleham Craft Works Ltd | Wholesale & retail | 2020 |
| Coleham Sandwich Bar & Deli Limited | Hospitality | 2005 |
| Coles Catering Ltd | Hospitality | 2019 |
| Colin Sharp Associates Limited | Professional & scientific | 2024 |
| Coliseum Capital Industrial Limited | Financial services | 2015 |
| Coliseum Capital Limited | Financial services | 2014 |
| College Fields (Bridgnorth) Management Company Limited | Households | 2012 |
| College Fields (Widnes) Residents Association Limited | Households | 2005 |
| Collier ROW Builders Limited | Administrative & support | 2015 |
| Collingwood Richardson and Co Limited | Financial services | 1984 |
| Collingwood Richardson Properties Ltd | Real estate | 2025 |
| Collison Electrical Services Limited | Construction | 2015 |
| Colnbrook Court Management Company Limited | Households | 1967 |
| Colourmart Holdings Ltd | Financial services | 2022 |
| Colourmart Software Ltd | Financial services | 2023 |
| Colours of Shrewsbury Limited | Professional & scientific | 2023 |
| Coltman-Bland Holdings Limited | Financial services | 2024 |
| Combined Physio Ltd | Professional & scientific | 2013 |
| Comfort Crew Ltd | Hospitality | 2014 |
| Comfort House Ltd | Households | 2016 |
| Comgro Limited | Professional & scientific | 2013 |
| Commercial Edge Ltd | Professional & scientific | 2022 |
| Commercial Enterprises Ltd | Hospitality | 2004 |
| Commercial Renovations Limited | Construction | 2024 |
| Community @ in Good Hands CIC | Health & social care | 2021 |
| Community Accounting Services Ltd | Professional & scientific | 2013 |
| Community Athletic Solutions Ltd | Professional & scientific | 2021 |
| Community Energy Twemlows 2 C.I.C. | Energy | 2015 |
| Community Energy Twemlows C.I.C. | Energy | 2015 |
| Community Money Advice Ltd | Health & social care | 2004 |
| Compact Crushers & Screeners Limited | Wholesale & retail | 2025 |
| Comparemobiles UK Limited | Information & communication | 2019 |
| Compass (Shropshire) Ltd | Professional & scientific | 2011 |
| Compass Land Surveys Limited | Professional & scientific | 1997 |
| Compl-X Ltd | Professional & scientific | 2013 |
| Complete Bike Training Limited | Professional & scientific | 2012 |
| Complete Property Service (UK) Limited | Transport & logistics | 2002 |
| Complete Social Work Limited | Health & social care | 2012 |
| Complete Sound Service Limited | Wholesale & retail | 2002 |
| Complete Tree Care Limited | Agriculture & fishing | 2001 |
| Compliance-Science Limited | Professional & scientific | 2024 |
| Compton Court (Four Oaks) RTM Company Limited | Households | 2006 |
| Compton Management Company Limited | Households | 2006 |