| Cappoquin Holdings Limited | Financial services | 2017 |
| Capri Pizza&Kebab House Ltd | Hospitality | 2019 |
| Capsaicin Limited | Professional & scientific | 2013 |
| Capsaicin Software Limited | Information & communication | 2015 |
| Capture the Curious Ltd | Information & communication | 2025 |
| Captured Collective Ltd | Information & communication | 2025 |
| Car Paint Kris Ltd | Wholesale & retail | 2024 |
| Car Trader ES Ltd | Wholesale & retail | 2016 |
| Car Trading Group Ltd | Wholesale & retail | 2018 |
| Caravan & Care Services (Lincolnshire) Ltd | Hospitality | 2025 |
| Carbon Focus Engineering Ltd | Construction | 2021 |
| Carboncoin Limited | Financial services | 2025 |
| Carconnect Finance Limited | Financial services | 2024 |
| Card Wise Ltd | Professional & scientific | 2023 |
| Cardiff Hernia Investments Ltd | Real estate | 2017 |
| Cardinal Supplies Limited | Wholesale & retail | 2013 |
| Cardinal Training Solutions Ltd | Education | 2024 |
| Cardinal W Ltd | Professional & scientific | 2025 |
| Cardioconsult Ltd | Education | 2015 |
| Cardiology Horizons LLP | | 2018 |
| Career Chimp Ltd | Administrative & support | 2020 |
| Career Prospects Limited | Administrative & support | 2017 |
| Careful Ideas Ltd | Construction | 2024 |
| Careology Clinic Ltd | Health & social care | 2023 |
| Carholme 2019 Ltd | Construction | 2019 |
| Carholme Food & Wine Ltd | Wholesale & retail | 2023 |
| Carholme Group Limited | Extraterritorial | 2025 |
| Carholme Lettings Ltd | Real estate | 2026 |
| Carholme Limited | Hospitality | 2025 |
| Carl Annable Trucking Ltd | Transport & logistics | 2024 |
| Carlburton Limited | Agriculture & fishing | 2020 |
| Carlburton Properties Ltd | Real estate | 2016 |
| Carlhorder Limited | Manufacturing | 2017 |
| Carline House Management Company Ltd | Administrative & support | 2013 |
| Carlisle Agnosco Limited | Professional & scientific | 2022 |
| Carlisle Bright Ltd | Construction | 2021 |
| Carlisle's Limited | Construction | 2006 |
| Carlton Electrical Services Limited | Construction | 2007 |
| Carlton Rise Management Company Limited | Households | 2002 |
| Carnell Consulting Ltd | Professional & scientific | 2015 |
| Carnell Investments Limited | Wholesale & retail | 2014 |
| Carole Wood Limited | Other services | 2022 |
| Caroline Writes Limited | Information & communication | 2016 |
| Carousel Equestrian Ltd | Manufacturing | 2022 |
| Carousel Huddersfield Limited | Hospitality | 2021 |
| Carousel Leeds Limited | Hospitality | 2023 |
| Carousel Worcester Limited | Hospitality | 2022 |
| Carptrix Products Ltd | Wholesale & retail | 2016 |
| Carr Farm Limited | Agriculture & fishing | 2017 |
| Carr Financial Limited | Financial services | 2006 |
| Carr Properties (Lincoln) Limited | Real estate | 2009 |
| Carrie Fuell Ltd | Other services | 2019 |
| Carrington Communications Limited | Professional & scientific | 2016 |
| Carruthers Capital Lincoln Ltd | Other services | 2019 |
| Cars Trading Group Lincoln Ltd | Wholesale & retail | 2025 |
| CAS Technical Solutions Ltd | Professional & scientific | 2007 |
| Casa Casa Limited | Real estate | 2019 |
| Casita Verde Property Management Ltd | Households | 2026 |
| Cask Creative Ltd | Information & communication | 2025 |
| Cass Collective Ltd | Other services | 2026 |
| Cassini Limited | Information & communication | 2014 |
| Castagna Services Ltd | Transport & logistics | 2024 |
| Castaway Retreats Limited | Hospitality | 2022 |
| Castiza Ltd. | Hospitality | 2022 |
| Castle Barber Ltd | Other services | 2020 |
| Castle Civils & Surfacing Limited | Construction | 2008 |
| Castle Consulting Associates Limited | Administrative & support | 2022 |
| Castle Environmental Services Ltd. | Construction | 2017 |
| Castle Exchange RTM Limited | Real estate | 2010 |
| Castle Hill Holdings Limited | Extraterritorial | 1963 |
| Castle Homes (Lincoln) Limited | Construction | 1998 |
| Castle Park Management Co. Ltd | Real estate | 2014 |
| Castle Print & Design Ltd | Manufacturing | 2018 |
| Castle Properties Lincoln Limited | Real estate | 2018 |
| Castle Square Developments Limited | Real estate | 1988 |
| Castle Square Properties Limited | Real estate | 1976 |
| Castle Square Securities Limited | Real estate | 2014 |
| Castlegate Construction (Lincoln) Limited | Construction | 2024 |
| Castlegate Homes Lincoln Limited | Construction | 2016 |
| Castlegate Roofing Services Limited | Construction | 2021 |
| Castlemaine Affiliates Ltd | Financial services | 2021 |
| Castlemaine Nominees Ltd | Professional & scientific | 2019 |
| Castlet EOT Limited | Other services | 2025 |
| Castlet Holdings Limited | Professional & scientific | 2013 |
| Cat Eyes Limited | Administrative & support | 2025 |
| Cat's Whisker Audio Limited | Information & communication | 2012 |
| Catalyst Delivery Ltd | Information & communication | 2026 |
| Cateriser Limited | Real estate | 1978 |
| Cathedral Air Conditioning Limited | Energy | 2020 |
| Cathedral Blinds Lincoln Limited | Wholesale & retail | 2022 |
| Cathedral City Brewing Limited | Hospitality | 2022 |
| Cathedral Developments Limited | Construction | 2025 |
| Cathedral Energy Surveys Ltd | Professional & scientific | 2024 |
| Cathedral Heights (Management) Limited | Hospitality | 2002 |
| Cathedral Masonry Contractors Limited | Construction | 2021 |
| Cathedral Property & Asset Management Limited | Real estate | 2025 |
| Cathedral Property Group Limited | Real estate | 2018 |
| Cathedral Quarter Holiday Lets Limited | Hospitality | 2022 |
| Cathedral Quarter Properties Ltd | Real estate | 2025 |
| Cathedral Quarter Risk Management Ltd | Other services | 2023 |