| Clondalkin UK Newco Limited | Administrative & support | 2014 |
| Cloudomni Limited | Information & communication | 2020 |
| Cloudviz Solutions Ltd | Information & communication | 2025 |
| Cloudz Bar Limited | Hospitality | 2024 |
| Club 500 Italia Limited | Wholesale & retail | 2014 |
| Club Class Property Services Limited | Construction | 2020 |
| Club Design Limited | Professional & scientific | 2001 |
| Club-Alert Ltd | Other services | 2017 |
| Clubland Limited | Hospitality | 2020 |
| Cmcs Services Ltd | Administrative & support | 2018 |
| CME Driveways and Patios Limited | Administrative & support | 2019 |
| CMH2 Technologies Limited | Professional & scientific | 2022 |
| Cmms Solutions Ltd | Information & communication | 2025 |
| CMR Services Bury Ltd | Professional & scientific | 2024 |
| CMY Flooring Ltd | Construction | 2026 |
| CNM Security Ltd | Other services | 2012 |
| Co-Channel Electronics Limited | Extraterritorial | 1980 |
| Coach Consultancy Ltd | Professional & scientific | 2024 |
| Coach Emotion Ltd | Information & communication | 2026 |
| Coach Options Limited | Administrative & support | 2001 |
| Coaching and Career Consultancy Limited | Other services | 2012 |
| Coast to Coast Holidays Limited | Administrative & support | 2015 |
| Coatman Pepper Limited | Real estate | 2014 |
| Cobe Consulting Limited | Professional & scientific | 2000 |
| Cobe Properties Ltd | Real estate | 2015 |
| Cobwebs Tottington Ltd | Wholesale & retail | 2019 |
| Cocktiails and Cream Ltd | Hospitality | 2024 |
| Code 25 Ltd | Information & communication | 2013 |
| Code Security & Electrical Ltd | Construction | 2019 |
| Codexan International Ltd | Information & communication | 2018 |
| Coffee & Cake Cafe Ltd | Hospitality | 2026 |
| Coffee Grind and Pack Ltd | Manufacturing | 2025 |
| Coform Company Services Limited | Administrative & support | 2017 |
| Coformuk Limited | Administrative & support | 2022 |
| COG PR Limited | Professional & scientific | 2010 |
| Cognitive Space Ltd. | Wholesale & retail | 2020 |
| Cognitiveconsult Limited | Information & communication | 2019 |
| Colin Barker Accounting Services Ltd | Professional & scientific | 2012 |
| Collaber Technology Ltd | Information & communication | 2026 |
| Collabora Rise Ltd | Wholesale & retail | 2024 |
| College Road Dent Limited | Health & social care | 2021 |
| College Sewing Machine Parts Holdings Limited | Extraterritorial | 2016 |
| College Sewing Machine Parts Limited | Wholesale & retail | 1987 |
| Collyhurst Road Property Group Ltd | Real estate | 2023 |
| Colne P&S Ltd | Hospitality | 2026 |
| Colourwave Ltd | Construction | 2021 |
| Columba Property Investments Limited | Real estate | 2020 |
| Combination Investments Limited | Real estate | 2024 |
| Combro Technology Limited | Information & communication | 2011 |
| Comfort Nest Homes Limited | Real estate | 2025 |
| Commando Charlie Limited | Arts & recreation | 2020 |
| Commercial Energy Specialists Ltd | Administrative & support | 2025 |
| Commercial Options Limited | Wholesale & retail | 2025 |
| Commercial Survey Reports Limited | Administrative & support | 2008 |
| Commodore Capital Ltd | Real estate | 2019 |
| Common Sense Finance Limited | Professional & scientific | 2000 |
| Common Sense Lending Limited | Professional & scientific | 2002 |
| COMMUNIC8 Media Ltd | Information & communication | 2019 |
| Communitree Outdoor Education Ltd | Education | 2017 |
| Community Learning Centre Limited | Education | 2012 |
| Compass Homes Living Limited | Real estate | 2021 |
| Compendium Escape Rooms Ltd | Other services | 2026 |
| Compensation Today Limited | Professional & scientific | 2001 |
| Complete Business Finance Limited | Financial services | 2021 |
| Complete Care NW Limited | Other services | 2007 |
| Complete Hire & Supply Ltd | Administrative & support | 2017 |
| Complete Home Services Ltd | Other services | 2019 |
| Completely Conkers Limited | Manufacturing | 2017 |
| Complex Case Management Limited | Health & social care | 2014 |
| Compliment NOT Compete Limited | Wholesale & retail | 2023 |
| Composite Door Sales Limited | Wholesale & retail | 2013 |
| Compound Construction Limited | Construction | 2018 |
| Compound Developments Ltd | Real estate | 2018 |
| Compris Professional Services Limited | Professional & scientific | 2015 |
| Compufix (UK) Limited | Construction | 1998 |
| Concealnothing Ltd | Arts & recreation | 2019 |
| Concievelabs Ltd | Wholesale & retail | 2019 |
| Condar Properties Ltd | Real estate | 2009 |
| Connellme Ltd | Wholesale & retail | 2025 |
| Connor Ventures Ltd | Financial services | 2026 |
| Conroy Construction & Devolpments Ltd | Construction | 2019 |
| Consensus Creative Ltd | Information & communication | 2025 |
| Consilio Consulting Limited | Professional & scientific | 2026 |
| Constructancy Limited | Professional & scientific | 2020 |
| Constructive Solutions Ltd | Construction | 2019 |
| Consult Health and Safety Limited | Professional & scientific | 2015 |
| Consulta Home Group Ltd | Real estate | 2024 |
| Consultancy AB Limited | Financial services | 2021 |
| Consulvent Limited | Wholesale & retail | 2018 |
| Contact Fusion Limited | Information & communication | 2021 |
| Contract Blinds Ltd | Construction | 2018 |
| Controlled Data Ltd | Information & communication | 2016 |
| Convenience Corner Bury Ltd | Wholesale & retail | 2024 |
| Conversion Kings Group Ltd | Construction | 2025 |
| Conversion Kings NW Ltd | Construction | 2024 |
| Convertaspace Ltd | Construction | 2021 |
| Convertex Digital Limited | Professional & scientific | 2023 |
| Convertyourgarage (NW) Ltd | Construction | 2015 |
| Convertyourgarage Ltd | Construction | 2012 |
| Convey Transport Ltd | Transport & logistics | 2024 |