| Conuprel Ltd | London | 2026 |
| Convenient Education Limited | London | 2024 |
| Convergence Trust | Wembley | 2020 |
| Convergent Intelligentia Limited | Hitchin | 2015 |
| Conversation and Culture Ltd | Bolton | 2026 |
| Conversation Guide Technologies Ltd | Winchester | 2025 |
| Conversation of Money Ltd | London | 2020 |
| Conversation Over Borders CIC | Brighton | 2021 |
| Conversation Works CIC | Buckfastleigh | 2022 |
| Conversation-Ally Ltd | London | 2025 |
| Conversational German Ltd | London | 2021 |
| Converse to Create Ltd | London | 2025 |
| Conversebsl Ltd | Watford | 2024 |
| Convertibles Driving School Limited | Wembley | 2023 |
| Convex Umbrella Ltd | London | 2021 |
| Conveyancing Excellence Training Hub Ltd | Nottingham | 2024 |
| Convo Zone Limited | Addlestone | 2023 |
| Convoy Academy Ltd | London | 2025 |
| Convoy Education Limited | London | 2013 |
| Conway Construction & Training Limited | Cannock | 2013 |
| Conway Education Centre Limited | Belfast | 1995 |
| Conway Merchant Navy Trust(The) | London | 1963 |
| Conwy Music Co-Operative Ltd | Denbigh | 2025 |
| Conzsec Security Training and Facilities Management Ltd | Brighouse | 2023 |
| COO Apps Ltd. | London | 2016 |
| Coogee Nursery School Limited | Birmingham | 2004 |
| Cook Academy Limited | Winchester | 2007 |
| Cook and Grow Together CIC | Malvern | 2019 |
| Cook Better EAT Well Ltd | Welwyn | 2024 |
| Cook Stars Doncaster South Ltd | Doncaster | 2022 |
| Cook Stars Limited | Cardiff | 2014 |
| Cook Stars MID Hants Limited | Alresford | 2020 |
| Cook Start CIC | Leicester | 2023 |
| Cookie Club 23 UK Ltd | Nottingham | 2021 |
| Cookie Girl Limited | London | 2017 |
| Cookies Kitchen Limited | Norwich | 2005 |
| Cooking 4 Life Skills Ltd | London | 2024 |
| Cooking and Crafts Limited | Edgware | 2025 |
| Cooking With LIZ C.I.C. | Liverpool | 2025 |
| Cooking With Noodles Limited | Harrogate | 2013 |
| COOKING4LIFE Limited | Gateshead | 2009 |
| Cookpal Ltd | Barnet | 2025 |
| Cooks Driving Success Ltd | Spalding | 2025 |
| Cookschool Futures CIC | Chipping Norton | 2026 |
| Cookschool Gregg Brown Limited | Banbury | 2025 |
| Cooky Limited | Manchester | 2023 |
| Cool APE Labs DI Jjmm | London | 2026 |
| Cool Ascents Limited | Bibury | 2008 |
| Cool Blue College Ltd | Consett | 1993 |
| Cool Brains Limited | Ascot | 2022 |
| Cool Cats Driving School Ltd | Basingstoke | 2021 |
| Cool for School Ltd | Leatherhead | 2020 |
| Cool Geography Limited | North Shields | 2025 |
| Cool IT World Limited | Croydon | 2009 |
| Cool Kidz Ltd | Belfast | 2026 |
| Cool Rowings Ltd | Romford | 2024 |
| Cool Running Technology Limited | Lancashire | 2000 |
| Cool Water Surf Adventure Ltd | Haverfordwest | 2025 |
| Coolam | London | 2009 |
| Coolearth Limited | Chester | 2006 |
| Coolkids Computing Ltd | Porthcawl | 2014 |
| Coolsportz Holiday Clubs Limited | Aston Cantlow | 2023 |
| Coombe Academy Trust | New Malden | 2012 |
| Coombe Valley Nursery (Callington) Limited | Callington | 2014 |
| Coombersewell Training CIC | Broadstairs | 2023 |
| Coombswood Education Limited | Guildford | 2023 |
| Cooper Aviation Training Limited | Kenilworth | 2017 |
| Cooper Winford Ltd | Manchester | 2020 |
| Cooperative Learning Consultants Limited | Birkhill | 2015 |
| Coopercloud Limited | Kington | 2022 |
| Cooperhay Ltd | London | 2002 |
| Coopers Driving School Ltd | Larkhall | 2022 |
| Coopersale Pre-School Ltd | Ongar | 2026 |
| COOPERSK9S Ltd | Chelmsford | 2024 |
| Coordinated Training Services Limited | Worcester | 1989 |
| Coorie Psychology Ltd | Paisley | 2026 |
| Copage Educational Services Ltd | Shrewsbury | 2006 |
| Copcraft Limited | Seaford | 2026 |
| Copdock & Washbrook Preschool | Ipswich | 2007 |
| Cope Consultants Limited | Cardiff | 2017 |
| Cope Consults Limited | Fareham | 2009 |
| Cope Ltd. | Lerwick | 1998 |
| Cope on the Road Ltd | Bolton | 2024 |
| Copeland Performing Arts Limited | London | 2024 |
| Coping Together CIC | Stoke-On-Trent | 2023 |
| Coping With Joy Ltd | Liverpool | 2026 |
| Copious Global Trading Ltd | Ballymena | 2019 |
| Copper Flame Software Ltd | Wallasey | 2016 |
| Copper Learning Ltd | Northampton | 2023 |
| Copper Sky Limited | Derby | 2023 |
| Copperfield Communication Ltd | London | 2011 |
| Copperfields Day Nursery Limited | Eastbourne | 2003 |
| Coppergate Training Limited | Hull | 2024 |
| Coppice Care Club and Pre-School Limited | Birmingham | 2012 |
| Coppice Childcare UK Limited | Rugby | 2013 |
| Coppice Primary Partnership | Maidstone | 2018 |
| Coppull St.John's Pre-School CIC | Chorley | 2021 |
| Copster Ventures Limited | Sheffield | 2026 |
| Copthall School | London | 2012 |
| Copthill School Limited | Grantham | 1997 |