| Costline Commercial Services Ltd | Professional & scientific | 2026 |
| Costplan (East) Limited | Professional & scientific | 2021 |
| Costplan Group Limited | Other services | 2023 |
| Costplan Safety Services Ltd | Professional & scientific | 2022 |
| Costplan Services (South East) Limited | Professional & scientific | 2014 |
| Cosy Cuisine Lounge and Bar Ltd | Hospitality | 2023 |
| Cotton Creates Limited | Professional & scientific | 2022 |
| Coty Brands Group Limited | Financial services | 1988 |
| Coty Export UK Limited | Professional & scientific | 1980 |
| Coty Holdings UK Limited | Administrative & support | 2018 |
| Coty Manufacturing UK Limited | Manufacturing | 1947 |
| Coty Services UK Limited | Administrative & support | 1937 |
| Coty UK Limited | Administrative & support | 1935 |
| Coty Uk&I Ltd | Wholesale & retail | 1932 |
| Coulten Locations Limited | Information & communication | 2014 |
| Country & Club Limited | Manufacturing | 2013 |
| Country Cosmetics Ltd | Wholesale & retail | 2014 |
| Country Cottage Gardens Limited | Administrative & support | 2013 |
| Country Funerals Limited | Other services | 2014 |
| Country Homes (Surrey) Limited | Construction | 2017 |
| Country Homes France LLP | | 2007 |
| Country Homes Limited | Real estate | 1979 |
| Country Pursuits Limited | Extraterritorial | 2021 |
| Countryside Security & Automations Ltd | Construction | 2022 |
| Countryside Security Group Ltd | Construction | 2022 |
| Countryside Security Solutions Ltd | Construction | 2022 |
| Countrystyle Energy Ltd. | Extraterritorial | 2008 |
| Countrystyle Group Limited | Water & waste | 2006 |
| County Clothes LLP | | 2014 |
| County Development (Company (Canterbury) Limited | Construction | 1960 |
| County Development Co.(Tankerton)Limited | Construction | 1964 |
| Countytrac Limited | Manufacturing | 1965 |
| Countywide Access Scaffolding Limited | Construction | 2021 |
| Couple Fit ND Ltd | Health & social care | 2022 |
| Courage Healthcare Ltd | Health & social care | 2021 |
| Court Lodge (the Wickets) Management Limited | Households | 2011 |
| Courteous Couriers Ltd | Transport & logistics | 2019 |
| Courthope Farming Limited | Real estate | 2010 |
| Cousins Auto Trading Ltd | Wholesale & retail | 2025 |
| Coutours Ltd | Administrative & support | 2019 |
| Cover Security Ltd | Administrative & support | 2023 |
| COX Freight and Logistics Ltd | Transport & logistics | 2021 |
| COX Training Ltd | Education | 2005 |
| Coypu Property Company Limited | Real estate | 1963 |
| CPC (Real Estate) Limited | Information & communication | 2009 |
| CPL Properties (Appledore) Ltd | Real estate | 2020 |
| CPL Transport Services (UK) Limited | Transport & logistics | 2001 |
| Cplt Companies Limited | Financial services | 2014 |
| Cplt Property Limited | Real estate | 2014 |
| CPM Sourcing Limited | Professional & scientific | 2008 |
| CPS Interiors London Limited | Professional & scientific | 2024 |
| CPS Maintenance and Electrical Limited | Other services | 2020 |
| CPS Renovations Limited | Other services | 2020 |
| CPS Scaffold Ltd | Construction | 2025 |
| Cpsw Consultancy Ltd | Health & social care | 2020 |
| Cpwise Developments Limited | Construction | 2012 |
| Crabtree & Crabtree Limited | Construction | 2003 |
| Craft Machine Ltd | Information & communication | 2011 |
| Crafted Deals Ltd | Wholesale & retail | 2025 |
| Crafts & Stitched Designs Ltd | Wholesale & retail | 2011 |
| Craftship Enterprise CIC | Arts & recreation | 2018 |
| Crafty Laser Creations Kent Ltd | Manufacturing | 2025 |
| Craig Gigg Consulting Ltd | Information & communication | 2025 |
| Crammond Properties Ltd | Real estate | 2023 |
| Cranbourne Hall Freehold Ltd | Households | 2022 |
| Crane Properties Limited | Real estate | 2008 |
| Crane Property Services Limited | Real estate | 2013 |
| Cranford Capital Ltd | Hospitality | 2018 |
| Cranmorians Ltd | Professional & scientific | 2024 |
| Crannis Design & Build Limited | Construction | 1999 |
| Craving House Ltd | Hospitality | 2025 |
| Crawley Insulations Limited | Construction | 2000 |
| Crawley Investment Management Ltd | Extraterritorial | 2017 |
| Crazypariscabaret Limited | Arts & recreation | 2011 |
| CRC Heating Solutions Ltd | Construction | 2022 |
| CRE Estates Ltd | Real estate | 2023 |
| CRE Holdings U.K. Limited | Financial services | 2022 |
| CRE8TIVEPLAY @ Sharen Jane's Limited | Health & social care | 2016 |
| Create Cadence Limited | Professional & scientific | 2020 |
| Create HC Limited | Professional & scientific | 2012 |
| Creativault Limited | Information & communication | 2026 |
| Creative Contractors Ltd | Construction | 2022 |
| Creative Development Services Limited | Real estate | 2014 |
| Creative Ironworks Limited | Manufacturing | 2017 |
| Creative Land and New Homes Limited | Real estate | 2019 |
| Creative Newsroom Limited | Information & communication | 2012 |
| Creative Planet London Ltd | Real estate | 2024 |
| Creative Planet Ltd | Professional & scientific | 2003 |
| Creative Property Portfolio Limited | Real estate | 2017 |
| Creative Relocations Limited | Real estate | 2017 |
| Credible Technologies Limited | Professional & scientific | 2012 |
| Creighton Sourcing Ltd | Administrative & support | 2024 |
| Creo Ground & Shell Works Limited | Construction | 2017 |
| Crescent Court (Staines) Management Limited | Real estate | 1967 |
| Cressingham Meville & Co Limited | Manufacturing | 1985 |
| Crest Care Services Ltd | Health & social care | 2014 |
| Crestford Development Ltd | Real estate | 2026 |
| Cresvix Ltd | Financial services | 2025 |
| CRG Carpentry Limited | Real estate | 2023 |
| Crichton Contracts Ltd | Construction | 2017 |