| Cmec Environmental Limited | Nottingham | 2006 |
| Cmec Skips Limited | Nottingham | 2022 |
| CMI Waste Management Limited | | 1987 |
| CML Skip Hire Ltd | London | 2026 |
| CMO Waste Clearance Limited | Sidcup | 2025 |
| CMP Ground Limited | Luton | 2024 |
| CMR Demolitions Limited | Crewe | 2001 |
| CMS Environmental Limited | Colchester | 2025 |
| CMS Waste & Recycling Ltd | Gravesend | 2025 |
| CMS Waste Management Limited | Porth | 2024 |
| Cmsi Limited | Kilmacolm | 2002 |
| CNA Construction Limited | Ruislip | 2023 |
| CNC Waste Ltd | London | 2024 |
| Cnmcl Ltd | Marlborough | 2025 |
| CNS Waste Ltd | Wakefield | 2022 |
| Co Waste Ltd | Bexley | 2024 |
| CO2 Compliance Limited | Dalry | 2007 |
| Coast Environmental Limited | Hailsham | 2024 |
| Coast Function Ltd | Tredegar | 2024 |
| Coast to Coast Recycling Limited | York | 2005 |
| COAST2COAST Clearance Ltd | Yeovil | 2025 |
| Coastal C&I Limited | High Wycombe | 2025 |
| Coastal Clear Water Limited | Belfast | 1995 |
| Coastal Clearances Ltd | Hove | 2025 |
| Coastal Drainage Solutions Ltd | Prestatyn | 2010 |
| Coastal OIL Tank Services Ltd | Littlehampton | 2018 |
| Coastal Recycling Ltd | Great Yarmouth | 2022 |
| Coastal Recycling Services Limited | Exeter | 2011 |
| Coastal Transport Site Services Limited | Waterlooville | 2002 |
| Coastal UK Group Limited | Exeter | 2006 |
| Coastal Waste Recycling Limited | Exeter | 2007 |
| Coben Distribution Ltd | Liverpool | 2017 |
| Cobra Environmental Services Limited | Hendon | 2025 |
| Cock Robin Residents Limited | Rugby | 1994 |
| Cockerills UK Drilling Ltd | Pickering | 2014 |
| Cococo&Co Ltd | Sheffield | 2024 |
| Codag SMT Limited | Somerset | 1990 |
| Cody Gardener Ltd | Edgware | 2025 |
| Coffee Coal Ltd | Esh Winning | 2019 |
| Coffee&Collect Ltd | London | 2026 |
| Coffey's Waste Management Ltd | Westerham | 2021 |
| Cofton Drainage and Jetting Services Ltd | Birmingham | 2020 |
| Cogan Pacific Ltd | East Ham | 2025 |
| Cognition Land and Water Limited | Enfield | 2005 |
| Cohart Asbestos Disposal Limited | Loughton | 2005 |
| Coinford Central Ltd | Horley | 2009 |
| Coinford Construction Limited | Burstow | 1990 |
| Coinford Limited | Burstow | 2004 |
| Colbrans Home Solutions Ltd | Feltham | 2023 |
| Colchester Asbestos Surveying Ltd | Colchester | 2025 |
| Colchester Waste Collection Limited | Colchester | 2021 |
| Cold Planing Ltd | Witney | 2014 |
| Coldcarr Recycling Limited | Ashbourne | 2002 |
| Coldstream Recycling Limited | Coldstream | 2013 |
| Cole Contractors Cardiff Limited | Cardiff | 2000 |
| Colebrooke Cleansing Ltd | Taunton | 2024 |
| Coleman Cabinets Limited | Leeds | 1998 |
| Coleman Remediation Services Limited | Birmingham | 2002 |
| Coleraine Skip Hire & Recycling Limited | Garvagh | 2003 |
| Coleshill Building Materials Ltd | Sutton Coldfield | 2025 |
| Coley and Wilkes Limited | Birmingham | 1976 |
| Coley Limited | Potters Bar | 1994 |
| Colin a. Robbie Partners Limited | Dundee | 2015 |
| Colin Corless Bolton Ltd | Bolton | 2017 |
| Colin's Property Clearance Limited | Ferndown | 2020 |
| Colinglen Contractors Limited | Belfast | 2002 |
| Colins Transport Ltd | South Ockendon | 2015 |
| Collard Environmental Limited | Hook | 2018 |
| Collect and Recycle Ltd | Sleaford | 2019 |
| Collect My Clothes Ltd | Widnes | 2018 |
| Collectclearclean Ltd | London | 2025 |
| Collecteco Limited | Bristol | 2008 |
| Collectmywaste Ltd | Telford | 2008 |
| Collectors & Recycling Ltd | Leigh-On-Sea | 2025 |
| Collier Industrial Waste Limited | Manchester | 1980 |
| Collins Cartons (Essex) Limited | Hornchurch | 2003 |
| Collins Containers Limited | Standish | 2010 |
| Collins Ross Ltd | London | 2018 |
| Collis Home Group Ltd | Reading | 2025 |
| Collison Skip Hire Ltd | London | 2026 |
| Colloidal Matters Limited | Quorn | 2022 |
| Colloide Engineering Systems Ltd | Magherafelt | 2002 |
| Colloide Site Services Ltd | Magherafelt | 2017 |
| Colne Valley Metals & Skip Hire Limited | Scammonden | 2001 |
| Colordesigns Limited | West Midlands | 1998 |
| Colt Contractors Limited | London | 2025 |
| Colt Garden & Waste Ltd | Swansea | 2024 |
| Colt Transport Ltd | Ruislip | 2022 |
| Colton & SON Utility Contractors Limited | Caernarfon | 2018 |
| Colton Drainage Services Limited | Caernarfon | 2015 |
| Columa Water Limited | Nottingham | 2013 |
| Columba Water Engineering Ltd | Cardiff | 2026 |
| Colwick Ltd | Langer | 2014 |
| Colwood Commercial Property Services Ltd | Eastbourne | 2017 |
| Colwood Grab Hire Ltd | Glasgow | 2025 |
| Combat Waste Solutions Ltd | London | 2023 |
| Combined Drier Technology Limited | Bristol | 2016 |
| Combined Power & Heat (Highlands) Ltd | Manchester | 2007 |
| Comfort Toilet Hire Limited | Luton | 2021 |
| Comfort Water Hygiene Limited | Witham | 2016 |