| Capital Shopfitting Services (Hemel Hempstead) Limited | Construction | 2000 |
| Capital Window Manufacturing (Commercial) Limited | Manufacturing | 1988 |
| Capital Window Manufacturing (Holdings) Ltd | Manufacturing | 2012 |
| Capital Window Manufacturing (Uxbridge) Limited | Manufacturing | 1984 |
| Captivating Classrooms CSR Community Interest Company | Education | 2022 |
| Carbon Fluids Limited | Administrative & support | 2010 |
| Cardiga Labs Limited | Information & communication | 2026 |
| Cardiga Limited | Wholesale & retail | 2024 |
| Carecloud Limited | Information & communication | 2013 |
| Carelab Healthcare Ltd | Administrative & support | 2022 |
| Careplex Limited | Health & social care | 2003 |
| Careplex Domiciliary Services (Sutton Coldfield) Limited | Health & social care | 2012 |
| Careplex Domiciliary Services Limited | Extraterritorial | 2012 |
| Cariad Kitchens Ltd | Wholesale & retail | 2024 |
| Carleton Limited | Extraterritorial | 1999 |
| Carleton Medical Limited | Other services | 2008 |
| Carleton Optical Equipment Ltd | Wholesale & retail | 1993 |
| Carlsburg College (UK) Limited | Education | 2013 |
| Carmastone Limited | Wholesale & retail | 2001 |
| Carrie Mano Ltd | Professional & scientific | 2022 |
| Cart and Beyond Limited | Wholesale & retail | 2025 |
| Cartforge UK Ltd | Information & communication | 2024 |
| Cartwheel UK Limited | Manufacturing | 2005 |
| Casaday 1 Ltd | Real estate | 2022 |
| Casaday 2 Limited | Real estate | 2024 |
| Casey Couriers Ltd | Wholesale & retail | 2025 |
| Casr Ltd | Hospitality | 2024 |
| Castle Hill Village Developments Limited | Construction | 2019 |
| Castle Radio Limited | Hospitality | 1961 |
| Castle Street Dance Studios Ltd | Arts & recreation | 2014 |
| Castlestone Investments Limited | Construction | 1965 |
| Cat's Back Cottages Ltd | Hospitality | 2026 |
| Catford Rhum Arrange Ltd | Manufacturing | 2021 |
| Cavendish Asset Management Limited | Professional & scientific | 2025 |
| Cavendish Construction Ltd | Administrative & support | 2002 |
| Cavendish Electrical & Plumbing Ltd | Construction | 2021 |
| Cavendish Group (London) Ltd | Financial services | 2023 |
| Cavendish Investment Management Limited | Extraterritorial | 2010 |
| Cavendish Network Services Limited | Information & communication | 2011 |
| Cavendish Property Maintenance Ltd | Construction | 2022 |
| CC Chesham Management Limited | Households | 2009 |
| CCD Renovations Limited | Manufacturing | 2018 |
| CCE Training Limited | Agriculture & fishing | 2019 |
| Ccel Ltd | Transport & logistics | 2025 |
| CD Commercial Services Ltd | Professional & scientific | 2025 |
| Cedarmore Limited | Extraterritorial | 2012 |
| Cellantenna Limited | Extraterritorial | 2004 |
| Cellsoc 40D Limited | Hospitality | 2025 |
| Centrix Solutions Limited | Professional & scientific | 1998 |
| Century 21 Films Limited | Arts & recreation | 2016 |
| Certax Accounting (S.Bucks) Limited | Other services | 2006 |
| Certifeye Limited | Wholesale & retail | 2016 |
| Cfonow Ltd | Administrative & support | 2016 |
| CG Design Ltd | Professional & scientific | 2004 |
| Chad Barrett Coaching Limited | Arts & recreation | 2023 |
| Chagonda Reid Limited | Real estate | 2022 |
| Chalfont Accounting Services Ltd | Professional & scientific | 2020 |
| Chalfont Financial Planning Limited | Financial services | 2013 |
| Chalfont Hearing Centre Limited | Health & social care | 2013 |
| Chanters Property Services Limited | Real estate | 2010 |
| Chantilly Communications Limited | Information & communication | 2014 |
| Charles Joseph Construction Ltd | Construction | 2021 |
| Charles Joseph Ltd | Construction | 2012 |
| Charleyrae Ltd | Wholesale & retail | 2020 |
| Charlo Architects Limited | Professional & scientific | 2012 |
| Charlotte Foley Limited | Health & social care | 2016 |
| Chartridge Holdings Ltd | Financial services | 2026 |
| Chartridge Park Limited | Other services | 1980 |
| Chartridge Surveying Limited | Professional & scientific | 2023 |
| Cheeld Plumbing and Heating Services Limited | Construction | 2024 |
| Chelsea Letting Services Limited | Real estate | 2011 |
| Cherry Hoggs Limited | Other services | 2019 |
| Cheryl Carlisle Consulting Limited | Information & communication | 2014 |
| Chesham & Little Chalfont PCN Ltd | Health & social care | 2023 |
| Chesham Alloy Wheel Refurbishment Repair and Powercoating Ltd | Wholesale & retail | 2019 |
| Chesham Control System Limited | Administrative & support | 2019 |
| Chesham Cottage Ltd | Hospitality | 2011 |
| Chesham Cricket Club Limited | Arts & recreation | 2013 |
| Chesham Diagnostics Limited | Manufacturing | 2018 |
| Chesham Food & Wine Limited | Wholesale & retail | 2020 |
| Chesham Foods Limited | Hospitality | 2019 |
| Chesham Fringe CIC | Arts & recreation | 2025 |
| Chesham Industrial Property Limited | Real estate | 2026 |
| Chesham Kitchens Ltd | Wholesale & retail | 2022 |
| Chesham Media and Performing Arts CIC | Arts & recreation | 2017 |
| Chesham Mobiles Limited | Wholesale & retail | 2024 |
| Chesham Podiatry Limited | Health & social care | 2015 |
| Chesham Preparatory School Trust Limited | Education | 1967 |
| Chesham Properties Limited | Real estate | 2013 |
| Chesham Renaissance Community Interest Company | Professional & scientific | 2017 |
| Chesham Rugs Gallery Ltd | Wholesale & retail | 2018 |
| Chesham Sports Company Limited | Arts & recreation | 1930 |
| Chesham Swimming Club Ltd | Arts & recreation | 2025 |
| Chesham Tyres Limited | Wholesale & retail | 2021 |
| Chesham United Association Football Club Limited | Arts & recreation | 1971 |
| Chesham Valeting Centre Ltd | Administrative & support | 2019 |
| Chesham Vision Limited | Wholesale & retail | 2018 |
| Chesham Youth Centre Ltd | Arts & recreation | 2011 |
| CHESHAM4X4 Ltd | Wholesale & retail | 2016 |
| Chess Construction Limited | Construction | 2013 |