| CTN Investment Ltd | Real estate | 2024 |
| Ctr-Consult Ltd | Professional & scientific | 2025 |
| Ctri Services Ltd | Professional & scientific | 2025 |
| Ctrl Customs Limited | Wholesale & retail | 2024 |
| CTS Aesthetics Ltd | Health & social care | 2026 |
| CTS Medical Ltd | Health & social care | 2025 |
| Ctskies Limited | Agriculture & fishing | 2025 |
| CU Industries Ltd | Wholesale & retail | 2026 |
| Cube Air Conditioning & Renewables Ltd | Construction | 2026 |
| Cube CC Ltd | Professional & scientific | 2019 |
| Cube Dynamic Limited | Extraterritorial | 2012 |
| Cube Investments Ltd | Real estate | 2011 |
| Cube Music Space Limited | Arts & recreation | 2021 |
| Cube Shopfitters Limited | Construction | 2008 |
| Cube Upholstery Limited | Manufacturing | 2012 |
| Cubed Property 2.0 Ltd | Real estate | 2017 |
| Cubic FM Limited | Construction | 2010 |
| Cubic FOX Limited | Transport & logistics | 2025 |
| Cubic Studio (Holdings) Limited | Professional & scientific | 2020 |
| Cubic Studio Limited | Administrative & support | 2001 |
| Cubit Facilities Maintenance Ltd | Administrative & support | 2017 |
| Cubit Recordings Ltd | Information & communication | 2008 |
| Cubley Investments Limited | Real estate | 1999 |
| Cubone Ltd | Arts & recreation | 2015 |
| Cuca Ltd | Administrative & support | 2010 |
| Cuccio Europe Ltd | Wholesale & retail | 2024 |
| Cucina Beeston Ltd | Hospitality | 2026 |
| Cucina Pizza Hucknall Ltd | Hospitality | 2024 |
| Cucina Pizza Ltd | Hospitality | 2025 |
| Cuckoo Games Limited | Manufacturing | 2019 |
| Cuckoo Grill Limited | Hospitality | 2019 |
| Cuckoobag Ltd | Wholesale & retail | 2008 |
| Cuddlekins Limited | Wholesale & retail | 2025 |
| Cuego Limited | Information & communication | 2016 |
| Cuillin Sound Music | Arts & recreation | 2015 |
| CUK Clothing Limited | Manufacturing | 2006 |
| Cullen Civils Limited | Construction | 2016 |
| Cullum Holdings Ltd | Financial services | 2024 |
| Culshaw & Deering Limited | Real estate | 2025 |
| Cultivate Innovation Ltd | Professional & scientific | 2016 |
| Cultivate IT Limited | Information & communication | 2007 |
| Cultur Labs Ltd | Information & communication | 2022 |
| Cultural Heritage Limited | Professional & scientific | 2015 |
| Culture Care @ Home Ltd | Public administration | 2020 |
| Culture Crossings Limited | Extraterritorial | 2017 |
| Cumberland (2) Limited | Administrative & support | 2019 |
| Cumberland (3) Limited | Hospitality | 2019 |
| Cumberland Company Management Limited | Administrative & support | 2004 |
| Cumberland Healthcare Limited | Extraterritorial | 2003 |
| Cumberland Secretarial Limited | Administrative & support | 2004 |
| Cumbria Nursing Services (Millfield) Limited | Health & social care | 1997 |
| Cummins & Co Property Consultants Ltd | Construction | 2024 |
| Cummins & Co Property Lettings and Management Ltd | Real estate | 2024 |
| Cunningham (Nottingham) Limited | Administrative & support | 2019 |
| Cunningham Lettings Limited | Real estate | 2008 |
| CUP of Tea Ltd | Wholesale & retail | 2003 |
| Cura Clothing Limited | Wholesale & retail | 2014 |
| Cure IT Roofing Ltd | Construction | 2023 |
| Curify Limited | Information & communication | 2021 |
| Curious Nottingham Ltd | Arts & recreation | 2016 |
| Curran Legacy Estates Ltd | Households | 2025 |
| Curryholics Ltd | Hospitality | 2025 |
| Curryz to Go TAS Cottage Balti Ltd | Hospitality | 2026 |
| Curson Carpentry Ltd | Construction | 2014 |
| Curtains 2GO Limited | Extraterritorial | 2012 |
| Curtis E J Noble Ltd | Real estate | 2020 |
| Curtis U.N. Limited | Wholesale & retail | 2015 |
| Curve Capital Partners LLP | | 2009 |
| Cushion (Nottingham) Limited | Wholesale & retail | 2000 |
| Cushionology Ltd | Manufacturing | 2021 |
| Custodian Homes Limited | Households | 2020 |
| Custom Automated Systems Ltd | Professional & scientific | 2014 |
| Custom Builds UK Ltd | Construction | 2023 |
| Custom Care Limited | Health & social care | 1995 |
| Custom Denning (UK) Limited | Wholesale & retail | 2023 |
| Custom Design Interiors Limited | Wholesale & retail | 2003 |
| Custom Duct Holdings Ltd | Financial services | 2023 |
| Custom Duct Limited | Manufacturing | 1975 |
| Custom Facilities Limited | Transport & logistics | 2020 |
| Custom Homes Ravenshead Limited | Construction | 2018 |
| Custom Metal Solutions Limited | Manufacturing | 2003 |
| Custom Paintwerx Ltd | Wholesale & retail | 2005 |
| Custom Radiator Covers Limited | Manufacturing | 2014 |
| Custom Signs Ltd | Manufacturing | 2021 |
| Custom Upholstery Limited | Manufacturing | 2004 |
| Customwest Trading Limited | Wholesale & retail | 2003 |
| Custos Clavis Limited | Manufacturing | 2025 |
| CUT Above Landscapes and Garden Services Limited | Administrative & support | 2013 |
| CUT Flower Garden Limited | Agriculture & fishing | 2021 |
| CUT My Price Ltd | Wholesale & retail | 2025 |
| CUT Price Ltd | Wholesale & retail | 2024 |
| Cutler Funeral Directors Limited | Extraterritorial | 2009 |
| Cutler Group Holdings Limited | Extraterritorial | 2009 |
| Cutlers Court (2022) R T M Company Limited | Households | 2022 |
| Cutsize Ltd | Wholesale & retail | 2026 |
| Cutter Brooks Limited | Wholesale & retail | 2017 |
| Cutts Properties Ltd | Real estate | 2023 |
| Cuzina Limited | Hospitality | 2016 |
| Cvek Ltd | Wholesale & retail | 2024 |
| Cvel Limited | Construction | 2026 |