| Cool Beanz Limited | Hospitality | 1997 |
| Cool Breeze Solutions Ltd | Manufacturing | 2024 |
| Cool Digital Limited | Information & communication | 2017 |
| Cool Girl Ltd | Other services | 2013 |
| Cool Hand MAN Productions Ltd | Real estate | 2012 |
| Cool Travel Ltd | Information & communication | 2012 |
| Cooleven Limited | Professional & scientific | 1998 |
| Coolmere Limited | Real estate | 1987 |
| Coolrainkk Trading Ltd | Wholesale & retail | 2025 |
| Cooper Quantity Surveying Limited | Administrative & support | 2002 |
| Coopers (Great Yarmouth) Limited | Wholesale & retail | 1938 |
| Coopers Close Management Co (Aslacton) Ltd | Households | 2022 |
| Coopers Country Limited | Arts & recreation | 2003 |
| Coopwells Trustees Limited | Professional & scientific | 2012 |
| Copdock & Washbrook Preschool | Education | 2007 |
| Copdock and Old Ipswichian Cricket Club Limited | Arts & recreation | 2020 |
| Copdock Enterprise Park Ltd | Real estate | 2020 |
| Copdock Hall Ltd | Real estate | 2014 |
| Copdock Holdings Limited | Real estate | 2017 |
| Copdock Mill Limited | Extraterritorial | 1983 |
| Copdock Motorcycle Events Ltd | Arts & recreation | 2014 |
| Copdock Transport Limited | Transport & logistics | 2015 |
| Copdock Valeting Ltd | Other services | 2020 |
| Copper Beech Medical Limited | Health & social care | 2019 |
| Copper Developments Ltd | Construction | 2025 |
| Copper Industries Ltd | Information & communication | 2006 |
| Copperbottom Properties Holdings Limited | Real estate | 2025 |
| Coppieters Consulting Limited | Information & communication | 2025 |
| Copping Holdings Limited | Financial services | 2025 |
| Copy Clik Copiers Ltd | Manufacturing | 2014 |
| Copywrighting & Creative Communications Limited | Information & communication | 2013 |
| Cora Holdings Limited | Financial services | 2025 |
| Cora HR and Employment Law Ltd | Professional & scientific | 2015 |
| Cora Legal Services Ltd | Professional & scientific | 2022 |
| Cora Whitstable Ltd | Real estate | 2025 |
| Coralgraph Inc Limited | Wholesale & retail | 2012 |
| Coralita Ariedales Ltd | Construction | 2016 |
| Coram Estates Limited | Households | 2023 |
| Coravin UK Ltd | Wholesale & retail | 2021 |
| Corbel Holdings Limited | Professional & scientific | 2015 |
| Corbel Solutions Limited | Wholesale & retail | 1998 |
| Cordale Spinney Limited | Households | 1959 |
| Cordless Phone World Limited | Wholesale & retail | 2008 |
| Core 10 Group Limited | Construction | 2019 |
| Core Cognitics Limited | Information & communication | 2019 |
| Core Design Limited | Information & communication | 2019 |
| Core Training Group Ltd | Wholesale & retail | 2025 |
| Corecraft Academics Ltd | Extraterritorial | 2026 |
| Corelance Ltd | Information & communication | 2026 |
| Corevista IT Ltd | Information & communication | 2026 |
| Corindale Properties & Land Limited | Construction | 2022 |
| Corinthian Developments East Anglia Ltd | Real estate | 2018 |
| Corittan Limited | Hospitality | 2026 |
| Corkhill Properties Ltd | Real estate | 2025 |
| Corner One Shop Ltd | Wholesale & retail | 2025 |
| Corner Plot Housing Ltd | Real estate | 2026 |
| Cornerhouse Furniture Limited | Wholesale & retail | 2018 |
| Cornerstone (Ipswich) Property Management Limited | Real estate | 2020 |
| Cornerstone Building Solutions Ltd | Construction | 2025 |
| Corness Consultancy Ltd | Information & communication | 2025 |
| Cornhill Bury Limited | Real estate | 2015 |
| Corps Protection Ltd | Administrative & support | 2024 |
| Corriere Veloce SRL Ltd | Professional & scientific | 2025 |
| Cory Brothers Limited | Transport & logistics | 2003 |
| COS Team Limited | Construction | 2023 |
| Coskcorp Limited | Information & communication | 2020 |
| Cosmetek Limited | Construction | 2008 |
| Cosmetica Natural Oils Ltd | Wholesale & retail | 2017 |
| Cosmic Coincidences Limited | Other services | 2020 |
| Cosmos Bathroom Distributors Limited | Transport & logistics | 1987 |
| Cosmos Trans Limited | Transport & logistics | 2023 |
| Cost Effective Accounting Limited | Professional & scientific | 2009 |
| Costykamy Ltd | Transport & logistics | 2025 |
| Cosy Club Furniture Ltd | Wholesale & retail | 2024 |
| Cosydoor Residential Estates Limited | Real estate | 2025 |
| Cotect Limited | Construction | 2003 |
| Coterie Vaults Holdings Limited | Real estate | 2021 |
| Coterie Vaults Limited | Transport & logistics | 2003 |
| Cotswold Retail Limited | Professional & scientific | 2021 |
| Cottrell Moore Limited | Administrative & support | 2009 |
| Coulters Limited | Agriculture & fishing | 2006 |
| Countora Limited | Professional & scientific | 2025 |
| Country Maids Anglia Limited | Other services | 2014 |
| Countrywide Accident Assistance Limited | Administrative & support | 2004 |
| County Property Maintenance Limited | Construction | 1997 |
| Court PIE Catering Limited | Hospitality | 1970 |
| Courtyard Cafe (Alder Carr Farm) Ltd | Hospitality | 2020 |
| Courtyard Estates (Suffolk) Limited | Extraterritorial | 1994 |
| Covedale Developments Limited | Real estate | 2019 |
| Coveted Events Co Ltd | Administrative & support | 2025 |
| Coward Holdings Ltd | Financial services | 2020 |
| Cowleaze Court Limited | Construction | 2023 |
| Coworth Estates Ltd | Construction | 2020 |
| Coworth London Ltd | Construction | 2024 |
| Coworth Property Limited | Construction | 2017 |
| Cowslip Valley Farms Limited | Arts & recreation | 1985 |
| COX Carpentry Limited | Construction | 2018 |
| COX Property Group Ltd | Financial services | 2023 |
| CP Creative Ltd. | Professional & scientific | 2010 |
| CP Industrial Electrical Limited | Construction | 2018 |