| Colloc Limited | Information & communication | 2026 |
| Colloco (Holdings) Limited | Financial services | 2020 |
| Colloco (Sheffield) Limited | Real estate | 2018 |
| Colloco Limited | Administrative & support | 2017 |
| Colmac Properties Limited | Real estate | 2021 |
| Colnago Property Limited | Real estate | 2025 |
| Colombo Street Food Orchard SQ Limited | Hospitality | 2021 |
| Colombo’S Trading (Private) Limited | Wholesale & retail | 2024 |
| Colour Kote Limited | Construction | 1998 |
| Colourcraft (Colours & Adhesives) Limited | Manufacturing | 1978 |
| Coloured Emotions Ltd | Information & communication | 2019 |
| Colourful CPD Ltd | Education | 2017 |
| Colourfull Arts Limited | Administrative & support | 2006 |
| Colroy Limited | Extraterritorial | 1966 |
| Colt UK Coaches Ltd | Transport & logistics | 2012 |
| Coltech Precision Engineering Limited | Manufacturing | 2010 |
| Colton Creative Ltd | Professional & scientific | 2021 |
| Colton Developments Limited | Real estate | 2005 |
| Colver Limited | Health & social care | 2017 |
| Colwill Services Limited | Construction | 2015 |
| Colwyn Convenience Limited | Wholesale & retail | 2025 |
| COM40TY Limited | Real estate | 2024 |
| Comagogo Limited | Professional & scientific | 2006 |
| Combes Services Ltd | Other services | 2019 |
| Combine Health Ltd | Administrative & support | 2020 |
| Combustion Inc Ltd | Wholesale & retail | 2016 |
| Come a Casa Restaurant Limited | Hospitality | 2021 |
| Comec Mechanical & Electrical Limited | Construction | 2019 |
| Comfort Care Bathrooms Limited | Wholesale & retail | 2024 |
| Comfort Lettings Limited | Real estate | 2025 |
| Comfort Touch Ltd | Health & social care | 2025 |
| COMFORT247 Ltd | Wholesale & retail | 2024 |
| Comfortable in Your Own Ltd | Health & social care | 2026 |
| Comfy@Homes Limited | Real estate | 2025 |
| Comheat Ltd | Construction | 2023 |
| Comitt Quality Services Ltd | Professional & scientific | 2024 |
| Comley Comms Solutions Ltd | Information & communication | 2019 |
| Commando Joes FUN and Fitness Ltd | Health & social care | 2009 |
| Commercecore Limited | Wholesale & retail | 2025 |
| Commercial Advice Hub Limited | Financial services | 2024 |
| Commercial Broker Directory Limited | Extraterritorial | 2024 |
| Commercial Deliveries (Europe) Limited | Transport & logistics | 1988 |
| Commercial Dowbusz Ltd | Real estate | 2025 |
| Commercial Laundry Rental Ltd | Manufacturing | 2022 |
| Commercial Leaseholders Ltd | Construction | 2023 |
| Commercial Property Partners Ltd | Real estate | 2020 |
| Commercial Property Ventures Ltd | Real estate | 2014 |
| Commercial ST (Residential) Limited | Real estate | 2012 |
| Common (Yorkshire) Ltd | Professional & scientific | 2019 |
| Common Burger Ltd | Hospitality | 2025 |
| Common Cowry Limited | Information & communication | 2022 |
| Common Ground Abbeydale Limited | Health & social care | 2012 |
| Common Ground Environmental Ltd | Agriculture & fishing | 2026 |
| Common Thing Clothing Co Ltd | Wholesale & retail | 2023 |
| Commonground Coventry C.I.C. | Manufacturing | 2018 |
| Commonplace Films Limited | Information & communication | 2025 |
| Commonwealth Human Ecology Council Limited | Administrative & support | 1969 |
| Commpound Ltd | Real estate | 2024 |
| Comms Electrical Limited | Construction | 2025 |
| Comms Installations Limited | Information & communication | 2015 |
| Comms Resale Ltd | Extraterritorial | 2012 |
| Commstec-It Ltd | Administrative & support | 2017 |
| Communi Link CIC | Education | 2024 |
| Communication House Developments Ltd | Construction | 2026 |
| Communications Resale Ltd | Extraterritorial | 2012 |
| Community Business Support Network CIC | Professional & scientific | 2021 |
| Community Companions Ltd | Health & social care | 2022 |
| Community Energy Association (England) Limited | Other services | 2014 |
| Community EYE Services Partnership (Cesp) LLP | | 2013 |
| Community Impact Partnership CIC | Other services | 2018 |
| Community Investment Services Limited | Professional & scientific | 2016 |
| Community Music Makers CIC | Education | 2024 |
| Community Outreach Ltd | Health & social care | 2012 |
| Community Recharge Limited | Administrative & support | 2023 |
| Community Recreation CIC | Professional & scientific | 2026 |
| Community Staffing Ltd | Administrative & support | 2024 |
| Community Training Services Limited | Education | 1999 |
| Community Wellbeing Restoration Point CIC | Health & social care | 2026 |
| Comp Tech (North West) Limited | Information & communication | 2008 |
| Compact Cars Limited | Wholesale & retail | 2015 |
| Compact Leisure Ltd | Hospitality | 2019 |
| Companion Mobility Limited | Transport & logistics | 2024 |
| Company Buyouts UK Ltd | Administrative & support | 2022 |
| Comparepmi Limited | Information & communication | 2025 |
| Compass Carpentry & Joinery Ltd | Construction | 2021 |
| Compass Driving School Ltd | Education | 2026 |
| Compass Trading Limited | Wholesale & retail | 2009 |
| COMPASS20 Ltd | Professional & scientific | 2020 |
| Compassionate TV Ltd | Information & communication | 2024 |
| Compelling Films and Television Limited | Information & communication | 2023 |
| Compelling Films and Television Limited | Information & communication | 2023 |
| Compelling Films Ltd | Information & communication | 2014 |
| Compelling Television Ltd | Information & communication | 2021 |
| Complete Accounting and Tax Solutions Ltd | Professional & scientific | 2015 |
| Complete Blasting Services Limited | Administrative & support | 2017 |
| Complete Build (Sheff) Ltd | Construction | 2024 |
| Complete Building Maintenance Ltd | Construction | 2025 |
| Complete Cafe Racer Limited | Wholesale & retail | 2013 |
| Complete Comtech Solutions Ltd | Information & communication | 2019 |
| Complete Construction Products Limited | Wholesale & retail | 2019 |