| Choudhury Holdings Ltd | Financial services | 2022 |
| Choudry&Sons Ltd | Wholesale & retail | 2026 |
| Choulli Limited | Hospitality | 2018 |
| Chowdhry Consultants Limited | Professional & scientific | 2019 |
| Chowdhury and Co Luton Limited | Wholesale & retail | 2010 |
| Chowdhury Group of Properties Ltd | Real estate | 2024 |
| Chowdhury Property Management Ltd | Real estate | 2021 |
| Chowdhury Zayn Consultant Ltd | Professional & scientific | 2015 |
| Chowki Builder Ltd | Construction | 2024 |
| Chriceci Healthcare Ltd | Health & social care | 2019 |
| Chris & AJ Homes Ltd | Real estate | 2023 |
| Chris & SAM Properties Ltd | Real estate | 2025 |
| Chris Attrill Plumbing Ltd | Construction | 2021 |
| Chris Bennett & Co LLP | | 2012 |
| Chris Riley Psychic Medium Ltd | Other services | 2016 |
| Chris Ward Engineering Limited | Professional & scientific | 2004 |
| Chriss Trans Ltd | Construction | 2015 |
| Christian Family Fellowship International | Other services | 2019 |
| Christian Friends and Family Forum | Other services | 2020 |
| Christie Aesthetics Limited | Other services | 2025 |
| Christine David HQ Ltd | Administrative & support | 2016 |
| Christmasishere Ltd | Wholesale & retail | 2025 |
| Chronictech Gaming Ltd | Other services | 2025 |
| Chronological Consulting Limited | Information & communication | 2024 |
| Chronos London Fragrance Ltd | Wholesale & retail | 2025 |
| Chrysalys Consultancy Ltd | Professional & scientific | 2022 |
| Chtk Ltd | Transport & logistics | 2021 |
| Chukumati Care Ltd | Health & social care | 2025 |
| Church Farm Autos Edlesborough Ltd | Wholesale & retail | 2026 |
| Church Mews Management Company Limited | Households | 2010 |
| Churchill Contract Services Group Holdings Limited | Administrative & support | 2010 |
| Churchill Contract Services Limited | Administrative & support | 1999 |
| Churchill Environmental Services Limited | Administrative & support | 2005 |
| Churchill Group Holdings Ltd | Financial services | 2026 |
| Churchill Health and Social Care Ltd | Public administration | 2019 |
| Churchill Health Care Ltd | Health & social care | 2005 |
| Churchill Managed Services Limited | Financial services | 2019 |
| Churchill Residential Ltd | Real estate | 2020 |
| CHYCARES4U Ltd | Health & social care | 2022 |
| Chyna Parys Limited | Real estate | 2018 |
| CHZ Ltd | Construction | 2020 |
| CI Property Investments Ltd | Real estate | 2023 |
| Cicerata Ltd | Administrative & support | 2024 |
| Cicero Drive 25-28 Limited | Households | 2003 |
| Cimed Health Care Limited | Health & social care | 2025 |
| Cinderella Clean Academy UK Ltd | Information & communication | 2026 |
| Cine Support Rigging Ltd | Construction | 2026 |
| Cineranter Ltd | Information & communication | 2022 |
| Cing Ltd | Wholesale & retail | 2026 |
| Cinnamon and Co. Delights Ltd | Wholesale & retail | 2026 |
| Cinnamon Healthcare Services Limited | Public administration | 2022 |
| Cinnamon Home & Lifestyle Ltd | Wholesale & retail | 2023 |
| Cioroch Transport Ltd | Transport & logistics | 2024 |
| CIP Decoration Limited | Construction | 2025 |
| Ciprian Toma Limited | Transport & logistics | 2019 |
| Ciprian&Barlad Ltd | Wholesale & retail | 2025 |
| Circle Cars (UK) Ltd | Transport & logistics | 2009 |
| Circle Deco Ltd | Administrative & support | 2019 |
| Circle DOT Ltd | Professional & scientific | 2023 |
| Circleflint Residents Association Limited | Households | 1983 |
| Circuit Cars Ltd | Transport & logistics | 2026 |
| Circuit Link Electrical Ltd | Construction | 2021 |
| Circular Recovery Ltd | Professional & scientific | 2013 |
| Circum Solutions Ltd | Information & communication | 2012 |
| Circumcision Centre Limited | Health & social care | 2012 |
| Cirstean Construction Ltd | Construction | 2016 |
| Cisscom Limited | Information & communication | 2014 |
| CIT Decorating Ltd | Construction | 2018 |
| Citadel Alliance Ltd | Hospitality | 2024 |
| Citi Apartments Addington Ltd | Real estate | 2017 |
| Citi Apartments Chapel Ltd | Real estate | 2017 |
| Citi Apartments Ltd | Real estate | 2017 |
| Citi Rooms Luton & MK Ltd | Real estate | 2018 |
| Citi Sialkot Cunstruction Company Limited | Construction | 2025 |
| Citi Support Services Ltd | Transport & logistics | 2023 |
| Citi Supported Living Limited | Real estate | 2025 |
| Citiline Accountants Ltd | Professional & scientific | 2014 |
| Citiline Consultants Ltd | Other services | 2017 |
| Citiline Properties Ltd | Other services | 2018 |
| Citizen DRY Cleaners Ltd | Other services | 2017 |
| Citizen Support Network Ltd | Information & communication | 2026 |
| Citrine Bridge Health Ltd | Health & social care | 2025 |
| Citrix Guru's Ltd | Information & communication | 2010 |
| City Gate (ST Albans) Management Company Ltd | Real estate | 2014 |
| City Group Apartments Ltd | Hospitality | 2016 |
| City Group Renovations Limited | Construction | 2019 |
| City Law Chambers Limited | Professional & scientific | 2015 |
| City Property Holdings Ltd | Real estate | 2023 |
| City Property Investment Group Limited | Real estate | 2017 |
| City Rentals Luton Ltd | Other services | 2019 |
| City Sourcing Ltd | Manufacturing | 2007 |
| City Vape Shop Ltd | Wholesale & retail | 2026 |
| Cityfame 1 Limited | Financial services | 2024 |
| Cityway Ltd | Transport & logistics | 2023 |
| Citywise Consulting Ltd | Professional & scientific | 2019 |
| Ciuk Logistics Ltd | Transport & logistics | 2026 |
| Ciuraru Distribution Ltd | Transport & logistics | 2018 |
| Civic Core Group Ltd | Construction | 2025 |
| Civil Matrix Limited | Construction | 2025 |
| Civisafe Site Services Ltd | Construction | 2024 |