| Careden HW Limited | Health & social care | 2026 |
| Careflex Limited | Manufacturing | 1991 |
| Carelton Consulting Limited | Professional & scientific | 2007 |
| Carersplus Limited | Health & social care | 2020 |
| Carib Bean Cafe Ltd | Hospitality | 2025 |
| Caribbean Gummy’S Ltd | Wholesale & retail | 2025 |
| Caring Hearts Services Ltd | Health & social care | 2025 |
| Carl Care & Support Ltd | Health & social care | 2018 |
| Carla Lloyd Event Management Ltd | Extraterritorial | 2024 |
| Carly Martin Limited | Real estate | 2024 |
| Carnelian Creative Studio Ltd | Information & communication | 2024 |
| Carnyx Services Ltd | Other services | 2024 |
| Caroline Banham Limited | Health & social care | 2024 |
| Carpathian Ltd | Wholesale & retail | 2026 |
| Carpendale EV Consulting Ltd | Professional & scientific | 2017 |
| CARPETS2U Sussex Limited | Wholesale & retail | 2025 |
| Carpi Limited | Wholesale & retail | 2021 |
| Carrera Construction London Ltd | Construction | 2018 |
| Carrick E-Commerce Ltd | Wholesale & retail | 2024 |
| Carrington House Right to Manage Company Limited | Households | 2009 |
| Carrion Cleaning Services Ltd | Administrative & support | 2025 |
| Carron Media Ltd | Information & communication | 2009 |
| CARS2CASH Ltd | Wholesale & retail | 2026 |
| Carter-Sneijder Ltd | Wholesale & retail | 2020 |
| Cartridge Atelier Ltd | Arts & recreation | 2023 |
| Carvalet Venko Fentazy Ltd | Administrative & support | 2025 |
| Carvi Holding Ltd | Financial services | 2023 |
| Carvi Living Ltd | Real estate | 2023 |
| CAS PT Limited | Arts & recreation | 2015 |
| Casa Latina Studio Ltd | Administrative & support | 2013 |
| Casaire Limited | Construction | 1973 |
| Casavent Limited | Wholesale & retail | 2019 |
| Case Communications Limited | Manufacturing | 2000 |
| Casegen Technologies Ltd | Information & communication | 2012 |
| Casella Holdings Limited | Manufacturing | 2022 |
| Casey Clothier Limited | Information & communication | 2018 |
| Cash and Keys Ltd | Real estate | 2025 |
| Cash Converters (UK) Limited | Wholesale & retail | 1995 |
| Cash Converters (UK) Stores Limited | Wholesale & retail | 2003 |
| Cash Converters UK Holdings Ltd | Wholesale & retail | 1996 |
| Cask and Crew Limited | Hospitality | 2025 |
| Caske Solutions Limited | Information & communication | 2022 |
| Caspian Hayes Ltd | Other services | 2024 |
| Cass Enterprises Ltd | Construction | 2023 |
| Cassinian Ltd | Professional & scientific | 2016 |
| Cast Studio Ltd | Professional & scientific | 2018 |
| Castle Cash & Carry Ltd | Wholesale & retail | 2014 |
| Castle Garden Design and Build Limited | Administrative & support | 2018 |
| Castle Landscapes Ltd | Administrative & support | 2014 |
| Castle Street Domus (55B) Ltd | Real estate | 2023 |
| Castle Street Domus (55C) Ltd | Real estate | 2023 |
| Cat Dragged in Films Limited | Information & communication | 2014 |
| Cat SAT on the MAT Limited | Administrative & support | 2010 |
| Catac Products UK Limited | Wholesale & retail | 2006 |
| Catalina Restructuring and Trading Advisory Ltd | Professional & scientific | 2026 |
| Catalyst Group Holdings Limited | Wholesale & retail | 2024 |
| Cater for YOU Limited | Wholesale & retail | 2003 |
| Catering Machinery Limited | | 1983 |
| Catherine Lowe Tuition Ltd | Education | 2024 |
| Catlin Motor Services Ltd | Wholesale & retail | 2020 |
| Cavam Partners Limited | Information & communication | 2016 |
| Caverstone Limited | Information & communication | 2016 |
| CAW Healthcare Limited | Health & social care | 2018 |
| Cayla Collective Ltd | Other services | 2026 |
| Cazador Consulting Ltd | Administrative & support | 2014 |
| Cazco Limited | Extraterritorial | 2024 |
| CB Finishes Limited | Wholesale & retail | 2024 |
| CBD and Build Services Ltd | Information & communication | 2024 |
| CBS Marlow Ltd | Construction | 2015 |
| CBUK26 | Education | 1994 |
| CC FIX Ltd | Manufacturing | 2023 |
| CC Franchising Worldwide Ltd | Hospitality | 2017 |
| CC Hydrodynamics Ltd | Professional & scientific | 2018 |
| CC Meeting Support Ltd | Administrative & support | 2018 |
| CC Warehouse Limited | Wholesale & retail | 2024 |
| CCB Evolution Limited | Extraterritorial | 2000 |
| CCS Building Services Limited | Construction | 2007 |
| CCS Facades Holdings Limited | Financial services | 2025 |
| CCS Facades Ltd | Construction | 2007 |
| CD Consulting Engineers Limited | Professional & scientific | 2018 |
| CD75781 Ltd | Wholesale & retail | 2021 |
| CDH Rentals Limited | Real estate | 2025 |
| CDK Plumbing & Heating Limited | Construction | 2019 |
| CDT (Group) Limited | Administrative & support | 2010 |
| Cdvi Ltd | Manufacturing | 1999 |
| Ceam Ltd. | Construction | 2014 |
| Cedar Stone Recruitment Limited | Information & communication | 2025 |
| Celebration Sales Ltd | Wholesale & retail | 2016 |
| Celestial Luxe Ltd | Wholesale & retail | 2024 |
| Celine K PVT Ltd | Professional & scientific | 2019 |
| Cellpipe Limited | Information & communication | 2004 |
| Celtstone Construction Limited | Construction | 2014 |
| Cementum Properties Ltd | Real estate | 2025 |
| Cemgate Ltd | Transport & logistics | 2007 |
| Centauro Gardens (High Wycombe) Management Company Limited | Households | 2016 |
| Centimax Limited | Manufacturing | 2020 |
| Central Chilterns Farmer Cluster CIC | Agriculture & fishing | 2023 |
| Central Turning Services Limited | Manufacturing | 2003 |
| Centralizin Soundz Limited | Arts & recreation | 2019 |
| Centre for Digital Education Ltd | Education | 2025 |