| Churchill Controls Limited | Stevenage | 1974 |
| Churchill Cricket BAT Repairs Ltd | Huntingdon | 2024 |
| Churchill Duffle Company Ltd | London | 2010 |
| Churchill Engineering Limited | Edgware | 2009 |
| Churchill Fine Bone China (Holdings) Limited | Stoke-On-Trent | 1987 |
| Churchill Fine Bone China Limited | Stoke-On-Trent | 1948 |
| Churchill Glass and Glazing Ltd | Cheltenham | 2023 |
| Churchill Memorials Ltd | Broxbourne | 2017 |
| Churchill Metalworks Ltd | Winscombe | 2018 |
| Churchill Paints Limited | Congleton | 1975 |
| Churchill Safes & Security Products Limited | Wolverhampton | 1991 |
| Churchill Steel Ltd | Totnes | 2023 |
| Churchill Tableware Limited | Stoke-On-Trent | 1941 |
| Churchill Windows Ltd | Hayes | 2005 |
| Churchill Windowsuk Ltd | Hayes | 2025 |
| Churchill's Confectionery Limited | Watford | 1989 |
| Churchmill Engineering Limited | Launceston | 2010 |
| Churchorganworld Limited | Oldham | 2012 |
| Churchview Joinery Limited | Wimborne | 2012 |
| Churchward County Trust Ltd | St. Ives | 2018 |
| Churn & Chill Ltd | Wirral | 2020 |
| Churn Ltd. | London | 2024 |
| Churnet Valley Garden Furniture Ltd | Leek | 2017 |
| Churnet Valley Joinery Ltd | Stoke-On-Trent | 2013 |
| Churnet Valley Precision Engineering Ltd | Leek | 2014 |
| Churpi Ltd | Aberdeen | 2011 |
| Chuse Ltd | Newcastle Upon Tyne | 2022 |
| Chuthanh Ltd | London | 2025 |
| Chutnaze Limited | Buckhurst Hill | 2025 |
| Chutree Limited | Camberley | 2018 |
| Chuug Limited | Cardiff | 2023 |
| Chwg Solutions Ltd | London | 2016 |
| CHX Products Limited | Bodmin | 1997 |
| CHX Products Services Limited | Bodmin | 2022 |
| Chxpz Ltd | Smethwick | 2018 |
| Chyinghpaw Ltd | Oxford | 2024 |
| Chykarenza Properties Kernow Ltd | Poole | 2025 |
| Chymera Machina Ltd | Leeds | 2021 |
| Chyng Yang Trading Co., Ltd | Cambridge | 2025 |
| Chyrowski Studio Limited | Bishop'S Stortford | 2024 |
| Chyvean Agricultural Services Ltd | Helston | 2024 |
| Château Paul Ltd | Welwyn | 2019 |
| CHÉ Reid Ltd | London | 2012 |
| CHĀ Limited | Abbots Langley | 2023 |
| CI Precision Limited | Salisbury | 1965 |
| CI Realisations 2022 Limited | London | 2011 |
| CI Systems Group Ltd | Hemel Hempstead | 2013 |
| CI Trading Limited | St. Helens | 2014 |
| CI W EN Limited | London | 2021 |
| Ci&Opex Services Limited | Grays | 2024 |
| CIA Fabrications Limited | Middlesbrough | 2026 |
| CIA Schä Limited | Huddersfield | 2024 |
| CIA Technology Global Ltd | Norwich | 2003 |
| Cian's Cupcake Toppers Ltd | Poole | 2014 |
| Ciao Chocolate Co. Ltd | Halesowen | 2024 |
| Ciao Fabrics by Hilary Ltd | Maidenhead | 2018 |
| Ciao L Manufacturing Limited | Wembley | 2025 |
| Ciao to BE Continued Ltd | Reading | 2023 |
| Ciaran Barker Ltd | Gosport | 2024 |
| Ciarynthe Ltd | Liverpool | 2025 |
| Ciasto OD Gosi Ltd | London | 2010 |
| CIB Electrical Ltd | Southampton | 2019 |
| Cibes Lift UK Limited | Mountsorrel | 2004 |
| Cibest Ltd | Southampton | 2021 |
| Cibi Foods Ltd | Oldham | 2026 |
| Cibo OPS. Limited | Herts | 2004 |
| Cibo Ventures Ltd | Oldbury | 2015 |
| Cibor Woodworking Machinery Ltd. | Wrexham | 2020 |
| Cibpro Ltd. | Glasgow | 2024 |
| CIBUS21 UK Limited | Tunbridge Wells | 2021 |
| Ciccarelli Italian Ice Cream Limited | Blyth | 2012 |
| Ciccetta's Ltd | Hamilton | 2025 |
| Ciccia Limited | London | 2025 |
| Cici Beds Limited | Sheffield | 2023 |
| Cici Emporium Ltd | Wincanton | 2024 |
| Cici’S Cold Brew Ltd | Biggleswade | 2026 |
| Ciclico Ltd | London | 2026 |
| Cicor Hartlepool Ltd | Hartlepool | 1929 |
| Cicor Newport Ltd | Newport | 1967 |
| Cicor UK Ltd | Milton Keynes | 2018 |
| Cicorel (London) Limited | Sherborne | 1967 |
| CID Cards Ltd | London | 2023 |
| Cidentify Ltd | London | 2021 |
| Cider by Baynes Ltd | Cheltenham | 2020 |
| Ciderhead Ltd | Bristol | 2019 |
| Ciderlands Ltd | Tiverton | 2019 |
| Cidneu Investment Limited | London | 2017 |
| Cieffe Studio Ltd | London | 2023 |
| Ciel (Concessions) Limited | London | 2003 |
| Ciel Celeste Labs Ltd | London | 2026 |
| Ciel Creations Ltd | Newton Aycliffe | 2017 |
| Ciel ET SEL Limited | Waltham Cross | 2026 |
| Ciele Beauty Ltd | Leeds | 2018 |
| Cielo Coffee House Ltd | Brighton | 2025 |
| Cielo Holdings Limited | South Ockendon | 2026 |
| Cielo Homes Ltd | London | 2021 |
| Cielo Jewellers Ltd | West Bromwich | 2022 |
| Ciem Services Ltd | London | 2016 |
| Ciera Stone & Terrazzo Limited | Croydon | 2025 |
| Cierco Ltd. | London | 2010 |