| Cairn College Ltd | Education | 2025 |
| Cakealicious LDN Ltd | Administrative & support | 2017 |
| Cakesnpastries World Ltd | Hospitality | 2016 |
| Calcor Building Contractors Ltd | Construction | 2020 |
| Calcor Exteriors Ltd | Construction | 2022 |
| Call Cleaning Services Ltd | Administrative & support | 2022 |
| Call JIM Ltd | Construction | 2020 |
| Call Property Services Ltd | Households | 2023 |
| Call Property Solutions Ltd | Administrative & support | 2021 |
| Camara Care Services Ltd | Health & social care | 2012 |
| Cambridge Broadband Networks Africa Ltd | Information & communication | 2020 |
| Campus Tuition Limited | Education | 2023 |
| Canary Wharf Academy Ltd | Education | 2019 |
| Capex Consultants Ltd | Real estate | 2024 |
| Capra Transport Limited | Transport & logistics | 2024 |
| Car Defiant Ltd | Wholesale & retail | 2022 |
| Car Shield Hire London Ltd | Wholesale & retail | 2024 |
| Car Trade Mart Limited | Wholesale & retail | 2018 |
| Care Compass Consulting Ltd | Professional & scientific | 2025 |
| Care Outreach Ltd | Health & social care | 2023 |
| Career Crafters Limited | Education | 2025 |
| Careph Consulting Ltd | Professional & scientific | 2026 |
| CAREUK247 Norfolk Ltd | Health & social care | 2023 |
| Carez Ltd | Health & social care | 2022 |
| Caring Crest Limited | Public administration | 2022 |
| Cart in Mart Ltd | Wholesale & retail | 2021 |
| Caruniverslondon Ltd | Wholesale & retail | 2019 |
| Casa Reformers Limited | Real estate | 2023 |
| Castingthemoment Ltd | Wholesale & retail | 2026 |
| Catch a Deal Limited | Wholesale & retail | 2024 |
| Catchpol Limited | Real estate | 2025 |
| Catermaster Equipment Ltd | Wholesale & retail | 2025 |
| Catherine Investments Ltd | Real estate | 2021 |
| Cave Building Construction Limited | Construction | 2021 |
| Cave Construction Limited | Construction | 2001 |
| CB Technology Xsports & Accounting Ltd | Wholesale & retail | 2013 |
| Cbhh Limited | Real estate | 2016 |
| CBR23 Ltd | Transport & logistics | 2024 |
| CCK Styling Ltd | Wholesale & retail | 2021 |
| CCS Removals Limited | Transport & logistics | 2019 |
| CD Property Management Ltd | Real estate | 2025 |
| Cedarise Limited | Professional & scientific | 2002 |
| Cedarnest Ltd | Administrative & support | 2025 |
| Ceennissi Limited | Health & social care | 2013 |
| Celia Apeagyei International Ltd | Professional & scientific | 2020 |
| Celvora London Ltd | Wholesale & retail | 2025 |
| Ceme Enterprise Limited | Hospitality | 2010 |
| Centenary Works Management Company Limited | Extraterritorial | 2010 |
| Centre for Engineering and Manufacturing Excellence Ltd | Real estate | 2001 |
| Centre Point Healthcare Services Ltd | Health & social care | 2023 |
| Centrepoint Care Services Limited | Health & social care | 2020 |
| Centrepoint Printing Services Limited | Manufacturing | 2025 |
| Ceramic Tile Holdings Limited | Financial services | 2022 |
| Cerberus Security Services Limited | Administrative & support | 2022 |
| CGM Building Ltd | Construction | 2021 |
| Cgsd UK Limited | Professional & scientific | 2019 |
| Chai Baby Ltd | Hospitality | 2023 |
| Chair Exercise Limited | Arts & recreation | 2020 |
| Challacombe Development Ltd | Construction | 2025 |
| Charles James Trew Limited | Transport & logistics | 2019 |
| Charlie Caine Holdings Ltd | Financial services | 2024 |
| Charlotte Mews Rainham (Management) Limited | Extraterritorial | 2016 |
| Charlyestate Limited | Real estate | 2024 |
| Charlytec Ltd | Information & communication | 2015 |
| Charsea Cargo Limited | Other services | 2025 |
| Chattyfox Ltd | Wholesale & retail | 2025 |
| Chaucer International Limited | Transport & logistics | 2010 |
| Cheddar Homes Ltd | Real estate | 2021 |
| Cheeky Getaways Ltd | Administrative & support | 2024 |
| Cheeseymoments Ltd | Hospitality | 2026 |
| Cheeta Lifestyle Solutions Ltd | Information & communication | 2024 |
| Chef KAY Catering Limited Ltd | Hospitality | 2026 |
| Chek Chek Plug UK Ltd | Hospitality | 2025 |
| Chelsea Transport Services Ltd | Transport & logistics | 2012 |
| Chelvam International Ltd | Construction | 2003 |
| Chelwick Design & Consultancy Ltd | Construction | 2018 |
| Cherry Red Limited | Manufacturing | 2024 |
| Cherry Red Studio Limited | Manufacturing | 2024 |
| Cherrytree Convenience Ltd | Wholesale & retail | 2023 |
| Cherubim and Seraphim Movement Church Ninth Hour Surulere District Ltd | Other services | 2024 |
| Chiazoka Consulting Limited | Public administration | 2026 |
| Chicken Hub (Rainham) Ltd | Hospitality | 2026 |
| Chidan Enterprises Ltd | Wholesale & retail | 2021 |
| Child and Family Social Care Services Limited | Health & social care | 2016 |
| Chilli Tree Limited | Hospitality | 2012 |
| China Health Spa Treatment Ltd | Other services | 2024 |
| Chixlux Limited | Other services | 2022 |
| Chmeleon Limited | Wholesale & retail | 2012 |
| Chmeleon Online Limited | Manufacturing | 2022 |
| Chop Chop Kitchen Ltd | Hospitality | 2026 |
| Chowdhury & Choudhury Ltd | Real estate | 2026 |
| Chris Forwood Limited | Information & communication | 2010 |
| Chris Theokli Ltd | Health & social care | 2018 |
| Chrisby Divine Ltd | Health & social care | 2026 |
| Christ Charles Enterprise (UK) Ltd | Wholesale & retail | 2026 |
| Christ the Resurrection Church Cherubum and Seraphim Limited | Other services | 2009 |
| Christabel Healthcare Ltd | Health & social care | 2022 |
| Christine Court Residents Association Limited | Households | 1991 |
| Chronos CIS Ltd | Construction | 2025 |
| Chronos Group Ltd | Information & communication | 2018 |