| Calibre Commercial Partnerships Ltd | Professional & scientific | 2022 |
| Calker Ltd | Real estate | 2015 |
| Calypso Search LLP | | 2024 |
| Cancer Active | Other services | 2003 |
| Cape Delivery Solutions Ltd | Transport & logistics | 2022 |
| Capehouse Development Consultancy Ltd | Other services | 2023 |
| Capehouse Investments Two Ltd | Real estate | 2025 |
| Capital Flow Ltd | Professional & scientific | 2023 |
| Cappo Search Ltd | Administrative & support | 2019 |
| Card Game Nexus Limited | Wholesale & retail | 2023 |
| Care Management Associates Ltd | Professional & scientific | 2023 |
| Carlins Software Solutions Ltd | Information & communication | 2008 |
| Carlus Acquisitions Limited | Financial services | 2020 |
| Carlus Limited | Financial services | 2018 |
| Carnatter Ltd | Administrative & support | 2020 |
| Caroline Massey Ltd | Administrative & support | 2011 |
| Cars RENT2BUY Ltd | Wholesale & retail | 2026 |
| Cartwright Landscapes Limited | Administrative & support | 2004 |
| Casa Zanna Ltd | Households | 2021 |
| Cash Hound Competitions Ltd | Wholesale & retail | 2025 |
| Cassia Health Ltd | Public administration | 2020 |
| Castle and Niall Veterinary Services Limited | Professional & scientific | 2002 |
| Castlemount Limited | Other services | 1987 |
| Cat 5 Communication Limited | Information & communication | 2009 |
| Catena Industries Ltd | Manufacturing | 2021 |
| Cattle Cleaning Ltd | Hospitality | 2024 |
| CAW Plumbing & Heating Limited | Construction | 2011 |
| Cbit Limited | Extraterritorial | 2010 |
| Cbrennan Engineering Ltd | Construction | 2016 |
| CBS Building Contractors Ltd | Construction | 2017 |
| Ccsf Group Limited | Wholesale & retail | 2019 |
| CDM Construction Ltd | Construction | 2021 |
| CDS Consultancy (UK) Ltd | Information & communication | 2013 |
| CED Accountancy Services Limited | Professional & scientific | 1999 |
| CED Auditing Services Limited | Extraterritorial | 2022 |
| Cedar Systems (MK) Limited | Information & communication | 1994 |
| CEM Trade Supplies Ltd | Wholesale & retail | 2025 |
| Central Exhibitions Ltd | Administrative & support | 2005 |
| Centreforce Limited | Wholesale & retail | 1987 |
| Centreforce Properties Limited | Professional & scientific | 2007 |
| Centric IT Solutions Limited | Information & communication | 2011 |
| Cfowers Ltd | Professional & scientific | 2026 |
| CGM Limited | Extraterritorial | 2021 |
| CGR Car Sales Ltd | Wholesale & retail | 2008 |
| Chalk Lion Distillery Limited | Manufacturing | 2025 |
| Champions of the Future Limited | Professional & scientific | 2001 |
| Chancery Nominees (Data One) Limited | Extraterritorial | 2009 |
| Chancery Nominees (Data Two) Limited | Extraterritorial | 2009 |
| Chancery Nominees (HFD 3) Limited | Extraterritorial | 2009 |
| Chancery Nominees (HFD 4) Limited | Extraterritorial | 2009 |
| Chancery Nominees (HFD 5) Limited | Extraterritorial | 2009 |
| Chancery Nominees (Plot 30 a) Limited | Extraterritorial | 2009 |
| Chancery Nominees (Plot 30 B) Limited | Extraterritorial | 2009 |
| Chapman-Nix Ltd | Other services | 2022 |
| Charismatic Classic Cars Limited | Construction | 2018 |
| Charles Wigley Brand Consulting Limited | Administrative & support | 2021 |
| Charlotte Bradley Film & TV Ltd | Information & communication | 2016 |
| Chennells Accounting Limited | Professional & scientific | 2026 |
| Cherished Vehicle Logistics Ltd | Transport & logistics | 2024 |
| Cherwell Doors Limited | Extraterritorial | 2006 |
| Cherwell Garage Doors Limited | Extraterritorial | 2007 |
| Cherwell Industrial Doors Limited | Construction | 2006 |
| Chesca Ventures Ltd | Information & communication | 2025 |
| Chestnut Rise (Gayton) Management Company Limited | Households | 2026 |
| Chilli's Dog Zone Ltd | Wholesale & retail | 2026 |
| Chilly Billy Limited | Manufacturing | 2025 |
| Chosen Arrow Ltd | Information & communication | 2019 |
| Chris Gilbert Services Limited | Administrative & support | 2008 |
| Christopher Hobson Limited | Professional & scientific | 1986 |
| Christopher Jones Antiques Limited | Wholesale & retail | 2021 |
| Christopher Long Limited | Transport & logistics | 2016 |
| Christopher Pallet Professional Services LLP | | 2005 |
| Christopher Pallet Wendover Limited | Real estate | 2021 |
| Churchill Waste Management Limited | Water & waste | 1996 |
| Circuit 2 Circuit Ltd | Transport & logistics | 2003 |
| City Quests Media Ltd | Information & communication | 2011 |
| CJM Consultancy UK Ltd | Administrative & support | 2009 |
| CJM Search Associates Ltd | Administrative & support | 2019 |
| Ck.Hada Limited | Arts & recreation | 2021 |
| CKT Consulting Ltd | Professional & scientific | 2021 |
| Clapham Waters (UK) Limited | Real estate | 2020 |
| Claremont Financial Planning Limited | Financial services | 1999 |
| Clarity Health Limited | Health & social care | 2013 |
| Clarkesburg Ltd | Hospitality | 2019 |
| Clarks Jewellers Ltd | Wholesale & retail | 2000 |
| Classic Sourcing Solutions Limited | Financial services | 2023 |
| Clayborne Developments Limited | Real estate | 2015 |
| Clayden Precision Engineering Limited | Professional & scientific | 2015 |
| Claydon Cycling Club CIC | Arts & recreation | 2021 |
| CLE Caravan Holidays Ltd | Hospitality | 2026 |
| Clean and Test Ltd | Administrative & support | 2025 |
| Cleaned IT Ltd | Administrative & support | 2020 |
| Clearpath Mortgage Services Ltd | Financial services | 2026 |
| Clickbuy.Ai Limited | Information & communication | 2024 |
| Clinical Trials Corporation Ltd | Health & social care | 2026 |
| Clinical Trials International Ltd | Health & social care | 2026 |
| Clinton PM Limited | Information & communication | 2005 |
| Clive Aldrich Limited | Health & social care | 2003 |
| Cloth & Cleaver Ltd | Administrative & support | 2025 |
| Cloud 9 Bookkeeping Limited | Professional & scientific | 2013 |