| Cognition Partners Employee Trustee Limited | Cambridge | 2022 |
| Cognition Training Ltd | Norwich | 2021 |
| Cognitive Behavioural Therapist Ltd | Egham | 2010 |
| Cognitive Dissonance Limited | Eastbourne | 2013 |
| Cognitive Therapy London Ltd | London | 2025 |
| Cognitor Ltd | Cardiff | 2017 |
| Cognitte Limited | Barnet | 2019 |
| Cognizant Consultancy Ltd | Southampton | 2012 |
| COH Consulting Services Ltd | London | 2017 |
| Cohen & Lockey Limited | Mansfield | 2013 |
| Coherence Enhancement Training Systems Limited | Surrey | 2004 |
| Cohesion Better Together Ltd | Birmingham | 2025 |
| Cohesion Consultancy Limited | London | 2018 |
| Cohesion Hair Limited | Bristol | 2001 |
| Cohiba Concepts Ltd | Birmingham | 2019 |
| Cohn Consulting Limited | Ramsgate | 2024 |
| Cohort Film Services Limited | Amersham | 2012 |
| Cohorted Communications Limited | Norwich | 2019 |
| Cohousing Scotland | Cupar | 2007 |
| Coia Hairdressing Limited | Glasgow | 2013 |
| Coiffure (Irchester) Limited | Wellingborough | 2019 |
| Coiffure Ltd | Somerset | 1988 |
| Coigach Community Development Company | Ullapool | 2010 |
| Coign Properties Limited | Woking | 2007 |
| Coil Slitting Letchworth Limited | Letchworth Garden City | 1993 |
| Coils N Curls Ltd | Ipswich | 2024 |
| Coimhearsnachd Bharraidh Agus Bhatarsaidh (Barra and Vatersay Community) Ltd | Isle Of Barra | 2005 |
| Coin - Laundrette and Wash Ltd | London | 2021 |
| Coin OP by Card Ltd | Fleet | 2023 |
| Coin OP Launderette (Yorkshire) Ltd | Bradford | 2025 |
| Coin OP Laundrette Limited | Newport | 2025 |
| Coin OP Laundry & DRY Cleaners Limited | London | 2026 |
| Coin OP Washeteria Ltd | Accrington | 2017 |
| Coin Street Community Builders Limited | London | 1984 |
| Coin Vault Ltd | London | 2025 |
| Coin-Op Launderette Ltd | Leicester | 2019 |
| Coinbridge Limited | Northleach | 2015 |
| Coiste NA N-Iarchimi | Belfast | 1999 |
| Cojam Limited | Poole | 2016 |
| Cojep UK | Lewisham | 2019 |
| Cojo 4 Limited | Nuneaton | 2020 |
| COK Services Limited | Dagenham | 2025 |
| Coker Services Ltd | Canvey Island | 2022 |
| COL Barb Ltd | Colchester | 2026 |
| COL Financial Services Ltd. | Northampton | 2014 |
| COL Wellness Ltd | London | 2024 |
| Col-Reno Limited | London | 1977 |
| Colab London Ltd. | London | 2012 |
| Colabella Hair Team Limited | Wolverhampton | 2013 |
| Coland Limited | London | 2012 |
| Colbeck - Hemsell Family Funeral Directors Ltd | London | 2025 |
| Colbert Capital Partners Ltd | Isleworth | 2020 |
| Colbert Consultancy Services Limited | Helston | 1995 |
| Colby Consulting Ltd | Whitehills Business Park | 2013 |
| Colch CUTZ1 Ltd | Colchester | 2026 |
| Colchester (T) Hairdressing Limited | Alton, Hampshire | 1998 |
| Colchester Archaeological Trust Limited | Colchester | 1981 |
| Colchester Barbers Limited | Colchester | 2024 |
| Colchester Canine Creche Ltd | Colchester | 2019 |
| Colchester Community Debt Support CIC | Abberton, Colchester | 2025 |
| Colchester Dog Field Ltd | Colchester | 2023 |
| Colchester DRY Cleaners Ltd | Colchester | 2021 |
| Colchester Garrison Officers' Club Limited | Colchester | 2000 |
| Colchester Launderette Ltd | Colchester | 2023 |
| Colchester Spraying and Decorating Ltd | Colchester | 2019 |
| Colchester SX Ltd | Colchester | 2016 |
| Colchester Valeting Ltd | Ipswich | 2021 |
| Colchurch Properties Limited | Ipswich | 2013 |
| Cold Barrels Ltd | Gloucester | 2025 |
| Cold Christmas Waste Management Limited | Ware | 2025 |
| Cold Developments Limited | Nottingham | 2014 |
| Cold Harbour Recording Company Limited | Berkhamsted | 1982 |
| Cold Hearted Tattoos Ltd | London | 2024 |
| Cold HUT Recovery Ltd | Chorley | 2023 |
| Cold Touch UK Limited | Preston | 2011 |
| Coldean Neighbourhood Planning Forum Limited | Brighton | 2022 |
| Colden Aviation Limited | Oxted | 2016 |
| Colder Refrigeration Services (SW) Limited | Melksham | 2009 |
| Coldfrost UK Ltd. | Erdington | 2017 |
| Coldharbour Contracts Ltd | Chelmsford | 2001 |
| Coldlion Ltd | London | 2025 |
| Coldproxy Ltd | London | 2020 |
| Coldroom Direct Limited | Hornchurch | 2017 |
| Coldside Limited | Dundee | 2024 |
| Coldstream Arch Ltd | Chippenham | 2026 |
| Coldtime Limited | Swanage | 2012 |
| Coldun Hair Ltd | London | 2020 |
| Coldwall Technology Solutions Ltd | Denby | 2013 |
| Coldwells Art Company Limited | Dalkeith | 2004 |
| Cole Aesthetics Clinic Ltd | Walsall | 2021 |
| Cole Company Capital Limited | Tamworth | 2024 |
| Cole Enterprises Limited | Ruislip | 1987 |
| Cole Park Consultancy Limited | Warrington | 2018 |
| Cole's Physiotherapy Limited | Oldham | 2010 |
| Cole's Salons Ltd | Bexley | 2010 |
| Colebrook and Sons Ltd | Poole | 2020 |
| Coleford Area Market and Coastal Towns Initiative Partnership | Coleford | 2006 |
| Coleman Aberdeen Ltd | Aberdeen | 2017 |
| Coleman Constructions (Southern) Ltd | London | 2013 |
| Coleman Consulting Services Ltd | Barrow In Furness | 2020 |