| Cinderella Prime Living Ltd | Real estate | 2025 |
| Cinema for ALL Ltd | Education | 2014 |
| Cinema Garage Limited | Wholesale & retail | 2018 |
| Cinema MOT Centre Ltd | Wholesale & retail | 2021 |
| Cinetic Equipment Limited | Administrative & support | 2025 |
| Cinnamon Days CIC | Health & social care | 2022 |
| Cinnia Limited | Professional & scientific | 2013 |
| Cinphonic Ltd | Information & communication | 2014 |
| Cinque Terre Restaurant Limited | Hospitality | 2020 |
| Cintride Limited | Extraterritorial | 2001 |
| CIP DUM Ltd | Transport & logistics | 2019 |
| Cipher Group Limited | Manufacturing | 2016 |
| Cipher International Limited | Wholesale & retail | 2001 |
| Ciprian Petre Limited | Transport & logistics | 2016 |
| Circle Chippy Limited | Hospitality | 2025 |
| Circuit 40S Ltd | Information & communication | 2026 |
| Circulate Digital Limited | Professional & scientific | 2014 |
| Cirieno Ltd | Information & communication | 2018 |
| Ciro Kebap & Cafe Ltd | Hospitality | 2024 |
| Cirrus Business Services Limited | Administrative & support | 2025 |
| Cirrus Development Limited | Information & communication | 2014 |
| Cirta Solutions Ltd | Information & communication | 2019 |
| Cisdi UK Limited | Construction | 2014 |
| Cisem Ltd | Wholesale & retail | 2020 |
| Cisse Auto Services Limited | Wholesale & retail | 2021 |
| CIT Digital Limited | Information & communication | 2003 |
| Citi Estates Ltd | Real estate | 2022 |
| Citi Padel 1 Ltd | Arts & recreation | 2026 |
| Citifi Ltd | Professional & scientific | 2004 |
| Citilights Property Company Ltd | Real estate | 2014 |
| Citizen Network Limited | Professional & scientific | 2010 |
| Citizen Sector Limited | Professional & scientific | 2015 |
| Citizenship First Appointee Accounts Ltd | Professional & scientific | 2001 |
| Citizenship First Ltd. | Health & social care | 1999 |
| Citizenship First Services Ltd | Health & social care | 2016 |
| Citracedar Limited | Wholesale & retail | 2025 |
| Citta Developments Limited | Real estate | 2002 |
| City Autos Plus Limited | Wholesale & retail | 2025 |
| City Burger Ltd | Hospitality | 2026 |
| City Care & Support South Yorkshire Ltd | Health & social care | 2019 |
| City Care Management Ltd | Real estate | 2020 |
| City Construction & Roofing Ltd | Construction | 2026 |
| City Finance (Developments) Limited | Professional & scientific | 1973 |
| City Force Homes Ltd | Real estate | 2020 |
| City Makers Shop Ltd | Wholesale & retail | 2016 |
| City Mobile VET Ltd | Professional & scientific | 2025 |
| City Mobility Transport Ltd | Transport & logistics | 2017 |
| City Motor Factors Ltd | Wholesale & retail | 2014 |
| City of London Locksmiths Limited | Administrative & support | 2013 |
| City of Sheffield Swim Squad Limited | Arts & recreation | 2014 |
| City Packaging Limited | Administrative & support | 2020 |
| City Plasma Services Limited | Professional & scientific | 2002 |
| City Psychiatric Consultancy Ltd. | Health & social care | 2014 |
| City Real Estate UK Limited | Construction | 1985 |
| City Road Barber Ltd | Other services | 2025 |
| City Road Community Childcare Ltd | Health & social care | 2019 |
| City Road Trading Estate Limited | Real estate | 2014 |
| City Service Group Ltd | Administrative & support | 2023 |
| City Spice & Pizza Ltd | Hospitality | 2026 |
| City Towers Limited | Real estate | 2017 |
| City Traels and Tours Ltd | Transport & logistics | 2025 |
| City Tyre S3 Ltd | Wholesale & retail | 2024 |
| City Vape Store Ltd | Wholesale & retail | 2026 |
| City Views (Yorkshire) Limited | Real estate | 2014 |
| City Wrap and Tints Ltd | Wholesale & retail | 2025 |
| Citycorp Estates Ltd | Construction | 2010 |
| Citywide Logistics Ltd | Transport & logistics | 2025 |
| Citywide Property Management Limited | Real estate | 2002 |
| Cityzenstays Ltd | Hospitality | 2024 |
| Civet Media Ltd | Professional & scientific | 2022 |
| Civil Sports Club Ltd | Arts & recreation | 2016 |
| CJ Accomodation Limited | Hospitality | 2024 |
| CJ Mcmanus Consulting Limited | Professional & scientific | 2024 |
| CJ Sport Massage Therapies Ltd | Other services | 2025 |
| CJA Associates Ltd | Professional & scientific | 2023 |
| Cjaam Ltd | Real estate | 2025 |
| Cjbrookes Ltd | Hospitality | 2021 |
| CJH Enterprises Limited | Hospitality | 2025 |
| CJK Financial Management Ltd | Professional & scientific | 2024 |
| CJM Roofing Ltd | Construction | 2018 |
| CJP Business Consulting Ltd | Professional & scientific | 2026 |
| CJP Direct Ltd | Wholesale & retail | 2020 |
| Cjrg Holdings Limited | Professional & scientific | 2025 |
| CJS Capital Solutions Limited | Professional & scientific | 2012 |
| CJS Interiors Limited | Construction | 2007 |
| Cjspace Ltd | Wholesale & retail | 2025 |
| Cjssdarwent Ltd | Administrative & support | 2014 |
| CK Clean UK Ltd | Administrative & support | 2023 |
| CK Crafthouse Ltd | Wholesale & retail | 2015 |
| CK EOT Trustee Limited | Financial services | 2024 |
| CK Onsite Ltd | Construction | 2024 |
| CK Plant Ltd | Transport & logistics | 2023 |
| CK Senda Limited | Wholesale & retail | 2021 |
| CKI Consulting Ltd | Information & communication | 2024 |
| Ckut Limited | Wholesale & retail | 2020 |
| CL Auto Service Ltd | Wholesale & retail | 2026 |
| CL International Search Limited | Administrative & support | 2008 |
| CL Training & Management Services Limited | Professional & scientific | 2025 |
| CL Trend Ltd | Wholesale & retail | 2024 |
| CLA Landscaping Services Ltd | Administrative & support | 2023 |