| Butts ASH Wood Residents Association Limited | Households | 1984 |
| Buzzflare Ltd | Professional & scientific | 2026 |
| Bybrook Management Company Limited | Households | 1994 |
| Byron Johnston Ltd | Arts & recreation | 2014 |
| C & J Godden Limited | Construction | 2007 |
| C B Dimensions Limited | Wholesale & retail | 2012 |
| C C H Build Solutions Limited | Construction | 2011 |
| C-Logik Ltd | Professional & scientific | 2021 |
| C.A.F. Europe Limited | Other services | 2025 |
| C.A.F. Holding Europe Limited | Other services | 2025 |
| C.S Hair Studio Ltd | Other services | 2021 |
| C88 Beheer IBC Limited | Other services | 2022 |
| C88 Holding Limited | Other services | 2022 |
| C88 Offshore Co. Limited | Other services | 2022 |
| Cafe Deco Limited | Hospitality | 2025 |
| Calima Software Ltd | Information & communication | 2017 |
| Cambion Limited | Professional & scientific | 2010 |
| Canefield Group Holding Limited | Other services | 2024 |
| Canefield ICT Nederland Limited | Other services | 2024 |
| Capt Emiel Verhoeven Limited | Other services | 2022 |
| Carpathian Properties Ltd | Real estate | 2026 |
| Carpentronix Ltd | Manufacturing | 2025 |
| Cashflow Entrepreneurs Ltd | Information & communication | 2017 |
| Castelsarrasin Limited | Professional & scientific | 2011 |
| Castle Glen Management Co. Ltd | Households | 1997 |
| Cavell Care Home Ltd | Health & social care | 2024 |
| CB Catering Ltd | Hospitality | 2019 |
| CB Planning Agent Ltd | Professional & scientific | 2019 |
| CC Media Productions Ltd | Professional & scientific | 2025 |
| CCH Rental Properties Limited | Real estate | 2021 |
| Cecom IBC Limited | Other services | 2024 |
| Cettuk Limited | Information & communication | 2015 |
| Cgeuk Ltd | Manufacturing | 2025 |
| Chalet Heating Limited | Other services | 2026 |
| Channelports Ltd | Transport & logistics | 1974 |
| Chanters Limited | Health & social care | 2005 |
| Charlier (Hythe) Limited | Real estate | 1936 |
| Charlier Construction Limited | Construction | 1974 |
| Charlier Mews Management Company Limited | Households | 2018 |
| Charlier Properties Limited | Real estate | 2011 |
| Charlie’S Logs Limited | Wholesale & retail | 2020 |
| Chens Garden Ltd | Hospitality | 2024 |
| Cherry Video Ltd | Professional & scientific | 2010 |
| Choosesport Ltd | Professional & scientific | 2023 |
| Church Rise Property Owners Ltd | Other services | 2012 |
| Cinque Hythe Limited | Information & communication | 2011 |
| Citi Nests Limited | Construction | 2014 |
| City Hotel Reservations Limited | Administrative & support | 2003 |
| CJA Contracting & Consulting Ltd | Manufacturing | 2025 |
| CJM Builders Ltd | Administrative & support | 2018 |
| Clean Air Adventures CIC | Administrative & support | 2022 |
| Clear Reach Solutions Limited | Administrative & support | 2015 |
| Cleland Buildings Ltd | Real estate | 2026 |
| Click Trick Media Limited | Information & communication | 2014 |
| CLICK2(UK) Ltd | Other services | 2017 |
| Cliff House Limited | Real estate | 2018 |
| Cliff Road Residents Association Limited | Households | 2000 |
| Clinargo Ltd | Information & communication | 2024 |
| Clubsconnect Ltd | Administrative & support | 2026 |
| Co-Unity HR Limited | Administrative & support | 2025 |
| Co-Unity Ltd | Administrative & support | 2023 |
| Coadjoint Limited | Information & communication | 2012 |
| Cocktails in the City London Limited | Wholesale & retail | 2014 |
| Coldwell & Shawyer Ltd | Construction | 2015 |
| Comchip Europe International Holding Limited | Other services | 2024 |
| Comchip Europe International Limited | Other services | 2024 |
| Comiclouds Limited | Professional & scientific | 2019 |
| Comotrade Sugar Limited | Other services | 2024 |
| Complete Garage Doors Limited | Construction | 2007 |
| Concept Camper Hire Limited | Administrative & support | 2010 |
| Concept Multi Car Limited | Manufacturing | 1998 |
| Confundo Ltd | Information & communication | 2025 |
| Connaught Management Ltd | Real estate | 2018 |
| Connect Upcycling Limited | Other services | 2020 |
| Contact One Office Limited | Professional & scientific | 2018 |
| Conyer Quay (Management) Limited | Households | 2001 |
| Copperlux Ltd | Manufacturing | 2024 |
| Copperplate Research Ltd | Other services | 2004 |
| Corporate and Executive Solutions Limited | Professional & scientific | 2006 |
| Corvo Jobs Ltd | Information & communication | 2026 |
| Country and Coast Properties Ltd | Construction | 2025 |
| Courtley Technical Consultancy Limited | Education | 2022 |
| Coverford Limited | Professional & scientific | 2008 |
| Crabble Mill Estate Management Company Ltd | Households | 2015 |
| Cream Directors Limited | Arts & recreation | 2008 |
| Creative Hub Events Ltd | Wholesale & retail | 2022 |
| Crest & Loom IBC Limited | Other services | 2025 |
| Crest & Loom Limited | Other services | 2025 |
| CS. Contractors Ltd | Construction | 2021 |
| Cured and Smoked Ltd | Manufacturing | 2023 |
| Curry in a Hurry Limited | Hospitality | 2023 |
| CVS Services BV Holding Limited | Other services | 2025 |
| CVS Services BV Limited | Other services | 2025 |
| Cyber Simplicity Ltd | Information & communication | 2009 |
| Cyril Orchard Management Ltd | Professional & scientific | 1999 |
| D P Vehicles Limited | Wholesale & retail | 2010 |
| D&A the Cleaning Radar Beheer Limited | Other services | 2025 |
| D&A the Cleaning Radar Limited | Other services | 2025 |
| D. W. Russell Limited | Construction | 1984 |
| DAB Rail Consultancy Ltd | Administrative & support | 2019 |