| Ctmp Services Ltd | Professional & scientific | 2025 |
| CTN Consultancy Ltd | Professional & scientific | 2024 |
| CTN Group Limited | Professional & scientific | 2017 |
| CTR Mandatory Limited | Wholesale & retail | 2006 |
| Ctrl London Ltd | Administrative & support | 2016 |
| Ctrlb Limited | Other services | 2018 |
| CTS Langley Limited | Wholesale & retail | 2024 |
| CTU People Limited | Professional & scientific | 2013 |
| CTU Property Limited | Real estate | 2012 |
| CTW Catering Ltd | Hospitality | 2009 |
| Cube Education Limited | Education | 2021 |
| Cube Hospitality Crew Ltd | Administrative & support | 2025 |
| Cube Residential Ltd | Real estate | 2024 |
| CUBE8 Ltd | Transport & logistics | 2022 |
| Cubian Holdings Ltd | Real estate | 2018 |
| Cuckmere House Limited | Households | 2003 |
| Cuddles and Smiles Maternity Ltd | Other services | 2025 |
| Cuerden Grange Management Company Limited | Households | 2007 |
| Culham Court Residents Management Company Limited | Households | 2004 |
| Culshaw Services Ltd | Real estate | 2021 |
| Culshaw-Lacey Services Ltd | Real estate | 2021 |
| Cult of Curry Limited | Wholesale & retail | 2025 |
| Cultural Arts CIC | Education | 2023 |
| Culture & Community Empowerment Cabin CIC | Health & social care | 2025 |
| Culworth House Residents Limited | Households | 2001 |
| Cumberland Court RTM Company Limited | Households | 2011 |
| Cumberland Street Management Limited | Households | 2010 |
| Cummins Builders Limited | Construction | 2003 |
| Cupping Recovery Limited | Health & social care | 2025 |
| Cupps Consulting Limited | Administrative & support | 2016 |
| Cura Global Limited | Professional & scientific | 2019 |
| Curam Domi Education Limited | Real estate | 2026 |
| Curam Domi Property Management Company Limited | Real estate | 2026 |
| Curam Domi Residential Care Limited | Real estate | 2026 |
| Curedoc Limited | Health & social care | 2022 |
| Curls N Bundles Ltd | Wholesale & retail | 2026 |
| Currentra Wholesale Ltd | Wholesale & retail | 2026 |
| Curtain Creation by Sheila Ltd | Other services | 2007 |
| Curvd Studios Ltd | Arts & recreation | 2025 |
| Curzon Park House (Management Company) Limited | Households | 2008 |
| Curzon Solar Ltd | Construction | 2025 |
| Cusbox Hot Limited | Wholesale & retail | 2026 |
| Custer Limited | Households | 1981 |
| Custom Scaffolding Ltd | Construction | 2022 |
| Customised Cleaning Solutions (London) Limited | Administrative & support | 2018 |
| Customs Warehouse Management Company Limited | Households | 2005 |
| CUT Throat Barber Ltd | Other services | 2017 |
| Cuthbert Manuel Limited | Wholesale & retail | 2023 |
| Cutprice Express Ltd | Wholesale & retail | 2023 |
| CV Food & Drink Co Ltd | Hospitality | 2017 |
| CV Hydro Hoist Limited | Extraterritorial | 2017 |
| CVC Building Contractors Ltd | Construction | 2024 |
| CVC Decorators Ltd | Construction | 2013 |
| Cvmg Limited | Information & communication | 2020 |
| Cvpt Ltd | Wholesale & retail | 2026 |
| CVT CRO Limited | Wholesale & retail | 2023 |
| CW Land Holdings Ltd | Real estate | 2025 |
| CW1 Logistics Ltd | Construction | 2020 |
| CWD Consult Limited | Professional & scientific | 2022 |
| CWF & Partners (TWB Accountants) Ltd | Professional & scientific | 2023 |
| CWF & Partners Ltd | Professional & scientific | 2014 |
| CWF Group Ltd | Professional & scientific | 2021 |
| CWF Partners Limited | Professional & scientific | 2019 |
| Cworld Limited | Financial services | 2010 |
| CWS Home Improvements Ltd | Construction | 2025 |
| CWS Windows Ltd | Construction | 2014 |
| CY Bailey Enterprise Limited | Hospitality | 2022 |
| Cyber 8 Ltd | Information & communication | 2022 |
| Cyber OPS Ltd | Information & communication | 2023 |
| Cyber Secured Ltd | Information & communication | 2020 |
| Cybernet Emea Limited | Wholesale & retail | 2021 |
| Cyberval Consulting Limited | Information & communication | 2026 |
| Cyclecare Repairs Limited | Other services | 2026 |
| Cyclr Systems Limited | Information & communication | 2013 |
| Cygnet Grove Management Company Limited | Households | 2009 |
| Cynosure Metals Limited | Wholesale & retail | 2023 |
| Cypie Ltd | Wholesale & retail | 2021 |
| Cypress Lodge Management Company Limited | Households | 1981 |
| Cyrmax Ltd | Health & social care | 2016 |
| CZ Holidays Limited | Administrative & support | 2019 |
| D & L Capontes Ltd | Hospitality | 2020 |
| D & M Toiletries Ltd | Wholesale & retail | 2005 |
| D & N Marble Company Limited | Manufacturing | 2003 |
| D and P Iver Ltd | Transport & logistics | 2026 |
| D Brown Plumbing Ltd | Construction | 2022 |
| D C B Groundworks Ltd | Construction | 2023 |
| D C Builders & Sons (Coventry) Limited | Construction | 2001 |
| D C Builders & Sons (West Midlands) Ltd | Construction | 2023 |
| D D Plastering Limited | Construction | 2023 |
| D F W M Ltd | Hospitality | 2026 |
| D H Cosmetics Smartrepairs Ltd | Administrative & support | 2009 |
| D J Grab Services Limited | Transport & logistics | 2011 |
| D J Group of Companies Ltd | Financial services | 2022 |
| D K Mills Ltd | Other services | 2015 |
| D K Obeng Group Enterprise Limited | Hospitality | 2024 |
| D K Obeng Group of Companies Limited | Professional & scientific | 2019 |
| D K Obeng Group Properties Limited | Real estate | 2023 |
| D K Obeng Group Unisex Salon Limited | Hospitality | 2024 |
| D Logistics Ltd | Transport & logistics | 2016 |
| D London Creations Ltd | Other services | 2025 |