| Canford Healthcare Limited | Administrative & support | 2006 |
| Canford Nominee Co 1 Limited | Extraterritorial | 2014 |
| Canford Nominee Co 2 Limited | Extraterritorial | 2014 |
| Canine Assisted Learning Limited | Education | 2016 |
| Canine Solutions Ltd | Administrative & support | 2023 |
| Canning Dental Clinic Ltd | Health & social care | 2022 |
| Cantaserv Ltd | Transport & logistics | 2025 |
| Cantcam Ltd | Construction | 2025 |
| CAP Investment Group Ltd | Construction | 2024 |
| CAP Management Group Ltd | Real estate | 2016 |
| CAP Management Ltd | Real estate | 2024 |
| CAP Property Group Ltd | Real estate | 2015 |
| Capinance Limited | Financial services | 2025 |
| Capital Bridge Group Limited | Financial services | 2025 |
| Capital Commercial FM Ltd | Construction | 2017 |
| Capital Commercials Ltd | Manufacturing | 2020 |
| Capital Housing Developments Ltd | Real estate | 2026 |
| Capital Ikon Ltd | Wholesale & retail | 2023 |
| Capital Investments (Langley) Ltd | Real estate | 2002 |
| Capital One Properties Ltd | Real estate | 2023 |
| Capital One Services Solicitors Ltd | Professional & scientific | 2017 |
| Capital Renovations & Extensions Ltd | Construction | 2019 |
| Capitalone Removals Limited | Transport & logistics | 2014 |
| Capitalwave Global Ltd | Real estate | 2014 |
| Capra Capital Ltd | Financial services | 2020 |
| Capri Recruitment Ltd | Administrative & support | 2019 |
| Capsugel UK Ltd | Other services | 2025 |
| Captain Real Estate Investments Limited | Real estate | 2025 |
| Captain School of Motoring Limited | Education | 2025 |
| Car Accident Repair Centre Limited | Wholesale & retail | 2014 |
| Car Body FIX Ltd | Wholesale & retail | 2024 |
| Car Leasing Made Simple Limited | Administrative & support | 2018 |
| Car Solution Slough Ltd | Wholesale & retail | 2025 |
| Car Therapy Centre Ltd | Wholesale & retail | 2020 |
| Car Transport Service Ltd | Administrative & support | 2015 |
| Car Valley Ltd | Wholesale & retail | 2021 |
| Car Wash & Valeting Centre Spartacus Ltd | Wholesale & retail | 2024 |
| Cara Homes Ltd | Construction | 2016 |
| Carasecurity Limited | Manufacturing | 2018 |
| Caraway House Care Limited | Health & social care | 2021 |
| Carbon Craze Ltd | Wholesale & retail | 2023 |
| Carbon Neutral Ltd | Professional & scientific | 2024 |
| Carbon Reduction Grants Ltd | Wholesale & retail | 2025 |
| Carbonara Crew Ltd | Wholesale & retail | 2022 |
| Carbongrip UK Ltd | Wholesale & retail | 2025 |
| Carco Motors Ltd | Transport & logistics | 2021 |
| Cardiac Care UK Ltd | Health & social care | 2023 |
| Care 247 on Call Limited | Administrative & support | 2023 |
| Care Advanced Limited | Health & social care | 2017 |
| Care Amaryllis at Home UK Ltd | Health & social care | 2023 |
| Care Cafe Ltd | Health & social care | 2023 |
| Care Concern Andover Limited | Health & social care | 2015 |
| Care Concern Fife Ltd | Health & social care | 2014 |
| Care Concern Limited | Health & social care | 2002 |
| Care Concern Management EA Limited | Health & social care | 2017 |
| Care Concern Management OA Limited | Financial services | 2007 |
| Care Concern Management TA Limited | Health & social care | 2013 |
| Care Concern Management WT Limited | Health & social care | 2023 |
| Care Concern Octo Limited | Financial services | 2016 |
| Care for Lives Ltd | Health & social care | 2026 |
| Care Solutions 4U Limited | Health & social care | 2026 |
| Care Staff Support Services Ltd | Health & social care | 2021 |
| Care Stars Services Ltd | Public administration | 2025 |
| Care Transformations International Ltd | Professional & scientific | 2021 |
| Care With YOU Ltd | Health & social care | 2025 |
| Careful Choices Ltd | Health & social care | 2020 |
| Carelifeline Ltd | Public administration | 2021 |
| Carelifeline Recruitment & Training Ltd | Public administration | 2025 |
| Carelifeline-Carers Ltd | Health & social care | 2026 |
| Careline Solutions Ltd | Administrative & support | 2015 |
| Carenet Traders LLC Ltd | Wholesale & retail | 2025 |
| Careonix Group Ltd | Health & social care | 2019 |
| Careoon Ltd | Health & social care | 2025 |
| CARERS4CARING Ltd | Public administration | 2023 |
| Caretarctica Ltd | Health & social care | 2024 |
| Cargo Express Worldwide Ltd | Transport & logistics | 2007 |
| Cargogogo Limited | Transport & logistics | 2023 |
| Caring Corner Limited | Health & social care | 2024 |
| Caring Hands United Ltd | Health & social care | 2024 |
| Caring Journeys Ltd | Transport & logistics | 2025 |
| Caring Professionals Healthcare Ltd | Health & social care | 2018 |
| Carless & Adams Limited | Professional & scientific | 2018 |
| Carley Harrison Bespoke Health Ltd | Health & social care | 2024 |
| Carlisle Management Ltd | Information & communication | 2023 |
| Carmen Service Ltd | Transport & logistics | 2017 |
| Carnegie Cowie Associates Limited | Administrative & support | 1995 |
| Carnoustie Construction Limited | Construction | 2022 |
| Carobar Ltd | Wholesale & retail | 2026 |
| Carol Services Ltd | Administrative & support | 2024 |
| Caroline Cutliffe Consultancy Services Ltd | Administrative & support | 2012 |
| Carpet Cleaning Services Experts Ltd | Administrative & support | 2022 |
| Carpet Trend Limited | Construction | 2015 |
| Carpol Limited | Wholesale & retail | 2011 |
| Carra Globe Ltd | Transport & logistics | 2025 |
| Carramac Limited | Mining & quarrying | 2022 |
| Cars Club Limited | Wholesale & retail | 2026 |
| Cars Club Traders Limited | Wholesale & retail | 2021 |
| Cart Quick Ltd | Wholesale & retail | 2025 |
| Cartcollection Ltd | Wholesale & retail | 2025 |
| Carter Sutton Group Ltd | Real estate | 2025 |