| Capernwray Parkland Farm Limited | Carnforth | 1998 |
| Capes Farms Limited | Andover | 2021 |
| Capestone Organic Poultry Limited | Haverfordwest | 1999 |
| Capiscan Limited | Kirkby Stephen | 2014 |
| Capital Agri International Ltd | Cambridge | 2017 |
| Capital CP Europe Limited | Haywards Heath | 2016 |
| Capital Dog Care Ltd | Canterbury | 2016 |
| Capital Furniture Components Limited | Alfreton | 2023 |
| Capital Hardwood & Components Limited | Alfreton | 2013 |
| Capital Softwood (Northern) Limited | Waterlooville | 2008 |
| Capital Softwood (Southern) Limited | Waterlooville | 2008 |
| Capital Softwood Ltd. | Waterlooville | 1998 |
| Capital Tree Services Ltd | Edinburgh | 2016 |
| Capitum Nature Limited | Moffat | 2025 |
| Capontoft Associates Limited | Spalding | 2015 |
| Cappagh Farms Ltd | Omagh | 2021 |
| Capplebarrow Limited | Kendal | 2022 |
| Capps Farming Partnersnip Ltd | East Grinstead | 2022 |
| Capreolus Ecology Ltd | Minehead | 2023 |
| Caprivi Limited | London | 2018 |
| Caps&Gills Limited | Westcliff-On-Sea | 2025 |
| Capsocket Holdings Limited | London | 2026 |
| Capsocket Limited | London | 2026 |
| Captain Haddock's Seafood Ltd | Liverpool | 2021 |
| Captains Hill Farm Ltd | Maghera | 2016 |
| Capture Specialist Baits Limited | Preston | 2024 |
| Capulford Ltd. | Ellon | 2003 |
| Capybean Ltd | London | 2025 |
| CAR124697 Ltd | London | 2026 |
| Caran Ltd | Trillick | 2016 |
| Carawal Shellfish Ltd | Perth | 2021 |
| Carbeth Clydesdales Ltd | Helmsdale | 2025 |
| Carbeth Fishery Limited | Hamilton | 2022 |
| Carbomap Limited | Edinburgh | 2012 |
| Carbon C-Questa C.I.C. | Saffron Walden | 2020 |
| Carbon Calling CIC | Stamford | 2023 |
| Carbon Community Trading Limited | Windsor | 2020 |
| Carbon Converters Ltd | Ormskirk | 2025 |
| Carbon Farming Limited | Cambs. | 2004 |
| Carbon Forestry & Land Management Ltd | Edinburgh | 2026 |
| Carbon Forestry Ltd | Market Harborough | 2006 |
| Carbon Forests Limited | Carlisle | 2020 |
| Carbon Keepers Ltd | Manchester | 2019 |
| Carbon Neutral Investors (UK) Limited | Cardiff | 2022 |
| Carbon Neutral Solutions Limited | York | 2006 |
| Carbon Neutral Wood Fuels Limited | Hereford | 2010 |
| Carbon Plantations 2 Limited | Thetford | 2022 |
| Carbon Plantations 3 Ltd | London | 2024 |
| Carbon Plantations Limited | Thetford | 2020 |
| Carbon Tree Care Ltd | Stevenage | 2025 |
| Carbon Ventures Africa Limited | London | 2022 |
| Carbon Zero Farm Enterprises Limited | Gorebridge | 2020 |
| Carbon Zero Organic Seaweed Ltd | Gorebridge | 2020 |
| Carbon Zero Reforesting Ltd | Gorebridge | 2020 |
| Carbon's Partnership Ltd | Reading | 2023 |
| Carboon Ltd | Newbury | 2023 |
| Carbost Pier | Carbost | 2007 |
| Carbrooke Farm Ltd | Newmarket | 2024 |
| Carbutts Turf Limited | Sandbach | 2003 |
| Carcant Estates Limited | Midlothian | 1954 |
| Carcini Hill Farm Ltd | Waterlooville | 2023 |
| Carclew Barton Ltd | Truro | 2023 |
| Carden Livestock Limited | Tayside | 2005 |
| Cardiff City Farm Limited | Cardiff | 2018 |
| Cardiff Friends for Pets Limited | Cardiff | 2017 |
| Cardiff Salad Garden C.I.C. | Cardiff | 2017 |
| Cardiff Tree Surgery Limited | Cardiff | 2021 |
| Cardinham & Rifle Range Commons Ltd | Bodmin | 2005 |
| Cardium Shellfish Limited | Port Of Boston | 2002 |
| Cardno Fishing Ltd | Fraserburgh | 2025 |
| Cardrona Fishings Limited | Tarbert | 2009 |
| Cardross Forestry Limited | Stirling | 2016 |
| Cardsmill Dairy Limited | Taunton | 2025 |
| Cardwell Farms Limited | Blackpool | 2003 |
| Care Farm Trust | Washington | 2009 |
| Care in the Garden CIC | Ryde | 2012 |
| Carewell Pest Control Limited | Banbury | 2025 |
| Cargill Cotton Limited | London | 2005 |
| Carglow Limited | Pershore | 1997 |
| Carines Farm Ltd. | Newquay | 1937 |
| Caring Locals Limited | Glasgow Central | 2026 |
| Caring Sharing Project Ltd. | Halesowen | 2017 |
| CARING4CRITTERS CIC | Scarborough | 2023 |
| Carisbrooke Stud Estate Limited | Hungerford | 2024 |
| Carish Central European Corp. Ltd | Cardiff | 2024 |
| Carisma Seafood Limited | Dundee | 2020 |
| Carkin Moor Farm Eggs Limited | Richmond | 2018 |
| Carl Austin Ltd. | Chathill | 2023 |
| Carl Butler Limited | Hockley | 2002 |
| Carl Hester Limited | Newent | 2015 |
| Carl LEE & Sons Limited | Royston | 1949 |
| Carl Mears Limited | Lichfield | 2010 |
| Carlburton Limited | Lincoln | 2020 |
| Carleton Farming Limited | Girvan | 2006 |
| Carleton Kennels Limited | Skipton | 2003 |
| Carleton Rode Farms Limited | Norwich | 1982 |
| Carley Tree Surgery and Groundworks Limited | Battle, | 2023 |
| Carlin Contracts Ltd | Ballymena | 2021 |
| Carlin Farms Limited | Holmfirth | 2000 |
| Carlingford Oyster Company (N.I.) Limited | Newry | 2019 |