| Cherry Trees Smallholding Ltd | Other services | 2015 |
| Cheshirewide Roofing & Building Ltd | Construction | 2021 |
| Chestnut Farm Nurseries Wisbech Limited | Agriculture & fishing | 1993 |
| Chickmacmoo Ltd | Hospitality | 2024 |
| Chilli Masters Spalding Takeaway Ltd | Hospitality | 2024 |
| Chilli Media & Publishing Limited | Information & communication | 2010 |
| Chillichump Ltd | Manufacturing | 2019 |
| Chimon Properties Limited | Real estate | 2023 |
| China Cabinet Limited | Wholesale & retail | 2003 |
| Chisletts (Spalding) Limited | Administrative & support | 1994 |
| Chivoiu Trans Limited | Transport & logistics | 2015 |
| Chloe's Kixx Boston Ltd | Education | 2026 |
| Chris & Jacob Limited | Arts & recreation | 2026 |
| Chris Dawe Mortgages Limited | Financial services | 2025 |
| Chris Eley Produce Limited | Wholesale & retail | 1985 |
| Chris Leonard Plant Ltd | Wholesale & retail | 2003 |
| Chris Padmore Ltd | Transport & logistics | 2009 |
| Chris Parker (Lincs) Ltd | Transport & logistics | 2023 |
| Chris Warnes Holdings Limited | Real estate | 2017 |
| Chris Warnes Limited | Financial services | 2015 |
| Chris Wright Builders Ltd | Construction | 2014 |
| Chrzanowski Company Ltd | Transport & logistics | 2013 |
| Church Farm Leisure Limited | Hospitality | 2022 |
| Church View Pool Limited | Arts & recreation | 2023 |
| Churchfield Properties Limited | Real estate | 2013 |
| Churchill Roofing and Building Ltd | Construction | 2026 |
| Churn Investments Limited | Real estate | 2017 |
| CI Lifting Solutions Ltd | Construction | 2013 |
| CI Structural Innovations Limited | Construction | 2025 |
| Ciantia Limited | Construction | 2020 |
| Ciantia Property Limited | Real estate | 2022 |
| Cibus Systems Limited | Information & communication | 2009 |
| Cichocki Limited | Transport & logistics | 2026 |
| Cicicatrans. Ltd | Transport & logistics | 2014 |
| Cifaldi&Sons Limited | Hospitality | 2025 |
| Cinmar Trans Ltd | Transport & logistics | 2021 |
| Ciobanu Lucian Trans Limited | Transport & logistics | 2016 |
| Citizens Advice South Lincolnshire | Information & communication | 2016 |
| Cito Long Ltd | Hospitality | 2025 |
| Ciéme Ltd | Wholesale & retail | 2024 |
| CJ & CA Penney Consulting Limited | Administrative & support | 2011 |
| CJJ Transportation Support Ltd | Administrative & support | 2014 |
| CK Roofing (Notts) Ltd | Construction | 2024 |
| Ckkc Limited | Extraterritorial | 2019 |
| Ckkc Portfolio Ltd | Real estate | 2019 |
| Cklear Limited | Information & communication | 2003 |
| CL Platinum Clean Ltd | Administrative & support | 2018 |
| Claire's Cheeky Cherubs Ltd | Education | 2012 |
| Clarabelle Holdings Limited | Financial services | 2025 |
| Clare Sami Ltd | Transport & logistics | 2017 |
| Clare Thorpe Limited | Professional & scientific | 2014 |
| Clarity and Confidence Coaching Ltd | Professional & scientific | 2024 |
| Clark Family Eyecare Ltd | Health & social care | 2011 |
| Clarke's Contracting Services Limited | Construction | 2005 |
| Clarkes UK Drainage Specialists Limited | Water & waste | 2024 |
| Clarkson Produce Ltd | Agriculture & fishing | 2025 |
| Classic Heritage PR & Media Ltd | Professional & scientific | 2023 |
| Claudiuremus-Trans Ltd | Transport & logistics | 2016 |
| Clay Lake Farm Limited | Agriculture & fishing | 1944 |
| Claybourne's (TS) Limited | Other services | 2014 |
| Clean & Clear PLB Services Ltd. | Hospitality | 2023 |
| Cleaned 4 U Limited | Administrative & support | 1997 |
| Clear Brands Media Ltd | Information & communication | 2024 |
| Clear View Roofing Ltd | Construction | 2019 |
| Clearspace Auctions Ltd | Administrative & support | 2025 |
| Clearvision Aerials Limited | Administrative & support | 2003 |
| Clem Moulis Agricultural Services Ltd | Agriculture & fishing | 2017 |
| Clements Terrace (Spalding) Management Company Limited | Real estate | 2015 |
| Cley Developments Limited | Construction | 1996 |
| Cley Hall Consultancy Limited | Hospitality | 2025 |
| Cley Hall Limited | Hospitality | 2026 |
| Cley Investments Limited | Real estate | 1995 |
| Click Save Smile Holdings Limited | Financial services | 2025 |
| Click Save Smile Limited | Wholesale & retail | 2015 |
| Click Unlimited UK Ltd | Wholesale & retail | 2011 |
| Clink Street Properties Limited | Real estate | 2000 |
| Cloth Project Ltd | Wholesale & retail | 2023 |
| CLOUD9 Roofing & Property Maintenance Ltd | Construction | 2025 |
| Cloudavionics Ltd | Information & communication | 2016 |
| Cloudsafeit Ltd | Information & communication | 2022 |
| Cloverfields Sports Therapy Ltd | Health & social care | 2025 |
| Clues Automotive Limited | Wholesale & retail | 2022 |
| CM Hire Ltd | Transport & logistics | 2020 |
| CM Mech Ltd | Professional & scientific | 2023 |
| CMB Cypher Ltd | Information & communication | 2024 |
| CMD Express Ltd | Transport & logistics | 2020 |
| CME Business Services Limited | Professional & scientific | 2013 |
| CNM Multiple Services | Extraterritorial | 2023 |
| Coach House 2026 Limited | Professional & scientific | 2020 |
| COB Consultancy Limited | Financial services | 2023 |
| Cobley Commercials Ltd | Wholesale & retail | 2025 |
| Cockrams Transport (Lincs) Limited | Wholesale & retail | 2010 |
| Cockrams Transport Limited | Information & communication | 1999 |
| Coda Builders Limited | Construction | 2006 |
| Coda Co. Equestrian Ltd | Wholesale & retail | 2023 |
| Codrut Paunescu Limited | Transport & logistics | 2016 |
| Coffee Lounge 51 Ltd | Hospitality | 2023 |
| Coggins Consulting & Coaching Ltd | Manufacturing | 2026 |
| Coleman Builders Ltd | Construction | 2024 |
| Coles Auto Collective Limited | Wholesale & retail | 2021 |