| CMH Plumbing Ltd | Construction | 2022 |
| Coalface Delivery Partners Ltd | Professional & scientific | 2017 |
| Cobbydale Rise (Silsden) Residents Management Company Limited | Households | 2026 |
| Cock O' the North Management Company Limited | Households | 2007 |
| Coed Issa Management Company Limited | Households | 2022 |
| Cognova Solutions Limited | Information & communication | 2011 |
| Cogworx Limited | Information & communication | 2016 |
| Cole Green Construction Group Limited | Real estate | 2023 |
| Colesgrove Trustees Limited | Financial services | 1965 |
| Colinwood Wholesale Ltd | Wholesale & retail | 2022 |
| College Court (Wigan) Management Company Limited | Households | 2011 |
| College Court Management Co. Limited | Households | 1980 |
| College Fields (Abbs Cross) Management Company Limited | Households | 2004 |
| College Fields Residents Association Limited | Households | 2001 |
| College Gardens (Bessacarr) Management Company Limited | Households | 2004 |
| Colliers Walk (Nottingham) Management Company Limited | Households | 2020 |
| Colosseum Sports Group Limited | Arts & recreation | 2024 |
| Commerce.X Ltd | Wholesale & retail | 2023 |
| Commercial and Residential Lease Management Limited | Real estate | 2023 |
| Commercial Business Units Ltd | Real estate | 2023 |
| Complete-Feet.Co.Uk Ltd. | Wholesale & retail | 2007 |
| Compound Creations Limited | Arts & recreation | 2022 |
| Compton Place Management Company Limited | Households | 1997 |
| Comroston Residents Association Limited | Households | 2013 |
| Concert Square Management Company Limited | Professional & scientific | 2002 |
| Concierge Collective Limited | Administrative & support | 2016 |
| Confident Finance Ltd | Financial services | 2024 |
| Congleton Road (Sandbach) Management Company Limited | Households | 2016 |
| Coningsby Gate Management Company Limited | Households | 2019 |
| Connected Insights Limited | Professional & scientific | 2020 |
| Connolly Mews Residents Association Limited | Households | 2001 |
| Conrad's Yard Management Company Limited | Households | 2006 |
| Constable Court (Manchester) Limited | Real estate | 2018 |
| Contact Patch Ltd | Professional & scientific | 2012 |
| Contactwise Limited | Information & communication | 2018 |
| Contract Strategy Ltd | Information & communication | 2026 |
| Contservice (UK) Limited | Transport & logistics | 2003 |
| Conza Media Limited | Information & communication | 2023 |
| Cool Breeze Air Conditioning Ltd | Construction | 2009 |
| Cooper Corporation Ltd | Information & communication | 2021 |
| Cooper Works (Enfranchisement) Limited | Households | 2009 |
| Coopership Limited | Construction | 2024 |
| Coopership Residential Limited | Real estate | 2026 |
| Copper Beech Canines Limited | Other services | 2018 |
| Coppice END Crowborough Residents Management Company Limited | Households | 2018 |
| Coral and Blue Ltd | Hospitality | 2020 |
| Coriss Limited | Professional & scientific | 2012 |
| Cornish Signs (Herts) Limited | Professional & scientific | 2012 |
| Corsicans Management Company Limited | Households | 1993 |
| Corsolv Limited | Information & communication | 2009 |
| Cossington Mews (Residents) Management Company Limited | Households | 2004 |
| Cost Estimating and Finance Consultants Limited | Professional & scientific | 2014 |
| Cottier Grange Estate Management Company Limited | Households | 2018 |
| Cotton Square Management Company Limited | Households | 2017 |
| Courlux Carpets Limited | Wholesale & retail | 2023 |
| Courtlands Kingswood Limited | Households | 2006 |
| Courtney Flooring Supplies Limited | Wholesale & retail | 2020 |
| Couzens Bakery Limited | Manufacturing | 1999 |
| Couzens Property Investment Ltd | Real estate | 2023 |
| COX & Sons Building Specialists Limited | Construction | 2015 |
| COX (Assets) Limited | Real estate | 1998 |
| COX Engineering (Holdings) Limited | Real estate | 1998 |
| CP Golf Ltd | Education | 2025 |
| CP One Global Ltd | Wholesale & retail | 2011 |
| CR Media Agency Ltd | Professional & scientific | 2025 |
| CR Tree Care Ltd | Agriculture & fishing | 2022 |
| Crackerjac Limited | Information & communication | 2003 |
| Craig Tools International Limited | Wholesale & retail | 2002 |
| Cranbury Place Management Limited | Households | 1983 |
| Crane Mead (Business Centre) Management Limited | Households | 2001 |
| Cranford House (Poundbury) Management Company Limited | Households | 2021 |
| Craton Holding Ltd | Financial services | 2026 |
| CRE8 BXR Community Interest Company | Arts & recreation | 2024 |
| CRE8 Gym Ltd | Arts & recreation | 2020 |
| Creative Innovations (UK) Ltd | Construction | 2010 |
| Creativediabetes Ltd | Administrative & support | 2017 |
| Crescenndo Ltd | Professional & scientific | 2021 |
| Cresswell Court Management Company Limited | Households | 2002 |
| Creswick Mews Management Company Limited | Households | 2013 |
| Crib Street Ware Ltd | Construction | 2024 |
| Cris & Dominic Limited | Transport & logistics | 2018 |
| Crispinsholders RTM Company Limited | Households | 2004 |
| Critical EYE Limited | Information & communication | 2009 |
| Crocketts Lane Management Limited | Households | 2017 |
| Crossbank (Salford) Management Company Limited | Households | 2021 |
| Crosswear Trading Limited | Wholesale & retail | 1974 |
| Crown Performance Ltd | Wholesale & retail | 2017 |
| Crownwood Baildon Management Company Limited | Households | 2007 |
| CS Electrical Supplies Ltd | Wholesale & retail | 2016 |
| CSH Construction (UK) Ltd | Construction | 2015 |
| CSK Automotive Limited | Wholesale & retail | 2023 |
| Cskt Property Investments Ltd | Real estate | 2016 |
| CUE Above the Rest Limited | Arts & recreation | 1985 |
| Cuerden Place Management Company Limited | Households | 2026 |
| Cullan Jones T/A the Waterside Ltd | Hospitality | 2025 |
| Culverden Park (Tunbridge Wells) Management Company Limited | Households | 2004 |
| Curl of Duty Limited | Arts & recreation | 2022 |
| Curwens LLP | | 2009 |
| Curzon Street Management Limited | Real estate | 1968 |
| Custom Bathroom and Plumbing Supplies Ltd | Wholesale & retail | 2024 |