| Chris Fingas and SON Property Facilities Ltd | Construction | 2019 |
| Chris Fingas General Building Services Ltd | Construction | 2013 |
| Chris Leaver Carpentry Ltd | Manufacturing | 2018 |
| Chris Wall Limited | Professional & scientific | 1976 |
| Christ's Hospital | Education | 2007 |
| Christ's Hospital Enterprises Limited | Hospitality | 1988 |
| Christal House Contracts Limited | Construction | 2001 |
| Christine Charman Consulting Limited | Professional & scientific | 2020 |
| Christmas Candle Productions Limited | Information & communication | 2012 |
| Christos Interior Designs Ltd | Professional & scientific | 2019 |
| Chroma Dental Limited | Health & social care | 2013 |
| Chroma Nima Limited | Manufacturing | 2019 |
| Chrysalis Partners Franchising Limited | Professional & scientific | 2018 |
| Chrysalis Partners Limited | Professional & scientific | 2017 |
| Chrysalis Partners South Ltd | Professional & scientific | 2019 |
| Church Farm Courtyard (Residents Association) Limited | Extraterritorial | 1993 |
| Church Schoolmasters and Schoolmistresses Benevolentinstitution | Other services | 1894 |
| Churcher's Care Limited | Health & social care | 2018 |
| Churches Osteopathic Practice Limited | Health & social care | 2006 |
| Churchlands Christ's Hospital Limited | Construction | 2009 |
| Churchlands Peel House Limited | Construction | 2018 |
| Churchlands Property Services Limited | Construction | 2001 |
| Churchlands Q H Limited | Construction | 2018 |
| Churchlands Springfield Limited | Construction | 2016 |
| Cidermill Farm Partnership | | 1996 |
| Cinch Drinks Ltd | Manufacturing | 2024 |
| Cinnamon Construction Limited | Construction | 2017 |
| Cintegra Limited | Information & communication | 2003 |
| Circa 10 Limited | Construction | 2017 |
| Circa 1885 Limited | Real estate | 1984 |
| Circle Biodynamics Limited | Education | 2021 |
| Cirlo Crafts Ltd | Wholesale & retail | 2020 |
| Cissbury Motors Limited | Wholesale & retail | 2002 |
| Citadel Business Services Ltd | Professional & scientific | 2021 |
| Citadel Ministries | Other services | 1990 |
| Citizens Advice in West Sussex (North, South, East) | Information & communication | 2005 |
| City Geomatics Limited | Professional & scientific | 2016 |
| City Wide Window Cleaning Specialists Limited | Administrative & support | 2025 |
| Civil Worx Limited | Construction | 2015 |
| CJA Property Management Limited | Other services | 2015 |
| CJC Carpentry & Joinery Ltd | Manufacturing | 2022 |
| CJL Care Services Limited | Health & social care | 2018 |
| CJR Carpentry, Joinery & Refurbishments Ltd | Manufacturing | 2018 |
| Cjsl Consulting Ltd | Information & communication | 2024 |
| CJW Management Limited | Other services | 2014 |
| Claire Ford Am&C Ltd | Professional & scientific | 2016 |
| Claire Phillips Art LLP | | 2011 |
| Clairthorpe Processes Limited | Administrative & support | 2013 |
| Clarema Services Ltd | Health & social care | 2022 |
| Clarity Through Numbers Limited | Professional & scientific | 2023 |
| Clark Agricultural Services UK Ltd | Administrative & support | 2015 |
| Clark Consultancy & Design Services Limited | Construction | 2021 |
| Clarke Consumer Credit Advisory Ltd | Professional & scientific | 2024 |
| Clarke Inventories Limited | Real estate | 2007 |
| Class ACT Solutions Limited | Wholesale & retail | 2009 |
| Class Technology Solutions Ltd | Information & communication | 2006 |
| Classic Historic Racing Limited | Administrative & support | 2009 |
| Classtech Solutions Limited | Extraterritorial | 2012 |
| Classy Canines Ltd | Other services | 2015 |
| CLEANERS1 Limited | Administrative & support | 2024 |
| Cleanstore Limited | Extraterritorial | 2005 |
| Clear Cctv Solutions Limited | Administrative & support | 2014 |
| Clearsight Consulting Ltd | Professional & scientific | 2016 |
| Click Click Boom Ltd | Information & communication | 2026 |
| Clickmymove.Com Limited | Real estate | 2024 |
| Clifton Africa Limited | Wholesale & retail | 2011 |
| Clifton Charterhouse Securities Limited | Arts & recreation | 1974 |
| Clifton Resources Ltd | Professional & scientific | 2018 |
| Clockhouse Podiatry Limited | Health & social care | 2004 |
| Cloudcasting Corporation Limited | Information & communication | 2017 |
| Cloudcasting LLP | | 2012 |
| Cloudswood Limited | Professional & scientific | 2018 |
| Cloudy and Belle Ltd | Wholesale & retail | 2024 |
| Clover Construction & Decorating Ltd | Construction | 2005 |
| CLS Groundworks & Construction Limited | Construction | 2009 |
| Club Inc Ltd | Professional & scientific | 2014 |
| Clubworks Golf Limited | Extraterritorial | 2017 |
| Cluj Inc Limited | Wholesale & retail | 2024 |
| CM & HR Chapman Ltd | Professional & scientific | 2012 |
| CM Autogroup Ltd | Wholesale & retail | 2024 |
| CM Finance Consulting Limited | Professional & scientific | 2018 |
| Cmas Resolve | Administrative & support | 1990 |
| CMP Building & Roofing Limited | Construction | 2019 |
| CNR Holdings Ltd | Financial services | 2024 |
| CNR Services Ltd | Wholesale & retail | 2026 |
| Co-Save Limited | Professional & scientific | 2003 |
| Coach House Mews (Cowfold) Limited | Households | 2018 |
| Coachcp Limited | Administrative & support | 2024 |
| Coast Networks Limited | Information & communication | 2006 |
| Coast to Coast Roofing Limited | Construction | 2013 |
| COCO2020 Ltd | Professional & scientific | 2023 |
| Cocoa Sisters Ltd | Manufacturing | 2025 |
| Cocoon Health Limited | Arts & recreation | 2018 |
| Code Care Ltd | Information & communication | 2026 |
| Codebright Limited | Information & communication | 2016 |
| Codical Limited | Information & communication | 2024 |
| Codingbadger Creative Limited | Information & communication | 2025 |
| Coeus Technologies Limited | Extraterritorial | 2014 |
| Coffee Jobs Limited | Professional & scientific | 2016 |
| Coffee Real Limited | Manufacturing | 2009 |