| Capital Tyres & Wheel Alignment Ltd | Wholesale & retail | 2025 |
| Capitax Financial Limited | Professional & scientific | 2010 |
| Caplet Pharma Limited | Wholesale & retail | 2020 |
| Caprent Limited | Real estate | 1990 |
| Capricorn Group UK Ltd | Administrative & support | 2015 |
| Capstone Developments Ltd | Construction | 2013 |
| Captains CUP Golf Events Ltd | Administrative & support | 2024 |
| Captar Vision Ltd | Information & communication | 2020 |
| CAPTIV8 Strategies Ltd | Professional & scientific | 2025 |
| Car Love Heart Ltd | Manufacturing | 2023 |
| Cararda Properties Limited | Real estate | 2023 |
| Carbon Integration Limited | Construction | 2023 |
| Care Shield Services Limited | Health & social care | 2017 |
| Careerplus Training Ltd | Education | 2022 |
| Carew Road Ltd | Real estate | 2024 |
| Caring Cleaning Services Ltd | Administrative & support | 2014 |
| Caring Hearts Fostering Ltd | Health & social care | 2017 |
| Caring Hearts Homes Ltd | Health & social care | 2019 |
| Caring Meadows Limited | Real estate | 2025 |
| Caring With a Difference Limited | Health & social care | 2013 |
| Carl Bignell Consultancy Ltd | Professional & scientific | 2023 |
| Carl Bignell Developments Limited | Construction | 2011 |
| Carl Bignell Ltd. | Real estate | 2007 |
| Carlive Limited | Financial services | 2025 |
| Carlton Price Ltd | Real estate | 2019 |
| Carma Ventures Ltd | Wholesale & retail | 2025 |
| Carnegie House RTM Company Limited | Households | 2022 |
| Carolina Carpaneda Interiors Limited | Professional & scientific | 2020 |
| Carpathian Carpentry Ltd | Construction | 2019 |
| Carr Properties Limited | Real estate | 2026 |
| Carrion Limited | Professional & scientific | 2008 |
| Carrus Chauffeurs Limited | Transport & logistics | 2013 |
| Cartan Properties Limited | Real estate | 2003 |
| Cartell Electrical Limited | Construction | 2004 |
| CAS Bridging & Commercial Finance Ltd | Financial services | 2014 |
| Casa FEZ Ltd | Real estate | 2026 |
| Casa Ynna Ltd | Real estate | 2025 |
| Casadivino Ltd | Wholesale & retail | 2024 |
| Cascades Konsult Limited | Professional & scientific | 2012 |
| Case Productions UK. Ltd | Professional & scientific | 2009 |
| Casey Homes Limited | Real estate | 2016 |
| Cask AID Limited | Hospitality | 2005 |
| Casper Mueller Kneer Ltd | Professional & scientific | 2010 |
| Casson Square Ltd | Real estate | 2019 |
| Castile View Properties LLP | | 2016 |
| Castle Kelly Holdings Limited | Financial services | 2023 |
| Castle Kelly Jointing Limited | Construction | 2019 |
| Castle Kelly Utilities Limited | Construction | 2009 |
| Castle Law Solutions Limited | Professional & scientific | 2017 |
| Castlekelly Property Limited | Real estate | 2018 |
| Cat Store Ltd | Wholesale & retail | 2025 |
| Catering and Events Ltd | Hospitality | 2023 |
| Cathartic Scents Ltd | Manufacturing | 2022 |
| Cavendish Assets Ltd | Real estate | 2012 |
| Cavendish Subco Limited | Real estate | 2018 |
| Caviar Group Limited | Wholesale & retail | 2026 |
| Cayca Medical Limited | Health & social care | 2013 |
| Cazilyer Hospitality Ltd | Hospitality | 2026 |
| Cazilyer Ltd | Information & communication | 2025 |
| Cazilyer Productions Ltd | Information & communication | 2026 |
| Cazilyer Technologies Ltd | Information & communication | 2026 |
| CB Gardening Limited | Administrative & support | 2024 |
| CB Retail Limited | Real estate | 2010 |
| CBS Energy Invest Ltd | Transport & logistics | 2022 |
| CBS Heating & Electricals Ltd | Construction | 2017 |
| Cbtc Signalling Limited | Real estate | 2018 |
| CC Hospitality Ltd | Hospitality | 2025 |
| CCA Holistic Ltd | Other services | 2025 |
| CCB Electrical & Lighting Ltd | Construction | 2023 |
| Ccjh Limited | Real estate | 2026 |
| CCN Store Ltd | Wholesale & retail | 2025 |
| CCT Driving Services Ltd | Transport & logistics | 2016 |
| CDL10 Ltd | Construction | 2024 |
| CDP Dent Limited | Health & social care | 2015 |
| Cedar Court Epping (Freehold) Limited | Real estate | 2006 |
| Cedar Court Epping Limited | Households | 1972 |
| Cedar Kingdom Limited | Real estate | 2022 |
| Cedars Catering ( Praed Street ) Limited | Hospitality | 2015 |
| Cedarstone Housing Ltd | Real estate | 2026 |
| CEL Management Limited | Professional & scientific | 2019 |
| Celestite Investment Holdings Ltd | Other services | 2024 |
| Centara Properties Limited | Real estate | 2017 |
| Centenary Sixes Ltd | Arts & recreation | 2025 |
| Central Flow Services Ltd | Construction | 2013 |
| Central House ( Slough) Ltd | Real estate | 2020 |
| Central Intelligence Security Solutions Ltd | | 2010 |
| Central London Portfolio Limited | Real estate | 2014 |
| Central Office and Commercial Properties Limited | Construction | 1973 |
| Central Place Ltd | Real estate | 2023 |
| Centrallis Consulting Limited | Information & communication | 2003 |
| Centre for Libyan Studies | Information & communication | 1996 |
| Centre of Culture and Learning CIC | Education | 2025 |
| Centrepoint Recycling Limited | Water & waste | 2017 |
| Centrix Healthcare Limited | Information & communication | 2024 |
| Centro Hotels Limited | Hospitality | 2015 |
| Century Partners NO 1 Limited | Real estate | 2006 |
| Cenz Tutors Ltd | Education | 2025 |
| Ceryx Ltd | Information & communication | 2008 |
| Cetn Limited | Health & social care | 2011 |
| CF Carpentry Limited | Construction | 2022 |