| Christopher Mitton Studio Limited | Administrative & support | 2024 |
| Christopher Porrett Limited | Wholesale & retail | 2025 |
| Christos Bakas I.T. Solutions Ltd | Information & communication | 2025 |
| Chromacrafft Ltd | Information & communication | 2025 |
| Chromaflow Coatings Ltd | Manufacturing | 2026 |
| Chrono Games Limited | Arts & recreation | 2017 |
| Chronus Solutions Services Ltd | Information & communication | 2023 |
| Chrysaetos Investments Limited | Financial services | 2015 |
| Chrysalis Sales Limited | Wholesale & retail | 2007 |
| Chrysis Engineering Limited | Professional & scientific | 2014 |
| Chucho's the Real Mexican Food Limited | Hospitality | 2019 |
| Chunky Chicken Heaton Ltd | Hospitality | 2021 |
| Church Lane Property Management Limited | Real estate | 2023 |
| Church Point (Leisure) Limited | Real estate | 1975 |
| Church Street Eckington Management Company Limited | Households | 2025 |
| Church View (LOW Fell) Management Company Limited | Households | 2021 |
| Church Walk Residents Association Limited | Real estate | 1989 |
| Churros Barcelona Ltd | Hospitality | 2019 |
| Chuse Ltd | Manufacturing | 2022 |
| CHW Surgical Ltd | Health & social care | 2025 |
| Chéz Northeast Ltd | Hospitality | 2026 |
| Cicero Independent Trading Ltd | Wholesale & retail | 2024 |
| Cielo Blanco Limited | Wholesale & retail | 2020 |
| Ciensys Limited | Professional & scientific | 2008 |
| CIK Engineering Ltd | Professional & scientific | 2025 |
| Cimnoj Limited | Professional & scientific | 2008 |
| Cinder's Gowns & Tailoring Ltd. | Other services | 2015 |
| Cindie Limited | Professional & scientific | 2020 |
| Cinterex UK Limited | Construction | 2009 |
| Cintra HR & Payroll Global Ltd | Administrative & support | 2017 |
| Cintra HR & Payroll Services Ltd | Information & communication | 1996 |
| Cintra HR Services Limited | Administrative & support | 2006 |
| Cintra HR Software Limited | Information & communication | 2015 |
| Cintra Payroll Services Limited | Information & communication | 1965 |
| Ciprian Olteanu Limited | Professional & scientific | 2018 |
| CIR Landscaping Solutions Ltd | Administrative & support | 2024 |
| CIR Payroll Solutions Ltd | Administrative & support | 2024 |
| Circadian Global Forwarding Limited | Transport & logistics | 2022 |
| Circle Entertainment Ltd | Information & communication | 2018 |
| Circle Red Investments Limited | Real estate | 2006 |
| Circle Red Properties (ST. James) Limited | Real estate | 2006 |
| Circle Red Properties Limited | Real estate | 2003 |
| Circlered Properties (Morpeth) Limited | Real estate | 2007 |
| Circuitsphere Limited | Information & communication | 2025 |
| Circular Bioenergy Technologies Ltd | Professional & scientific | 2024 |
| Circular Fusion Ltd | Professional & scientific | 2023 |
| Circulis Group Limited | Professional & scientific | 2014 |
| Cirkle Brand Consultancy Ltd | Professional & scientific | 2024 |
| CIS Industry Ltd | Construction | 2026 |
| Citadel Homes (Cumbria) Limited | Construction | 1998 |
| Citadel Homes (DV) Limited | Construction | 2021 |
| Citadel Homes (DV1) Limited | Construction | 2018 |
| Citadel Homes (DV2) Limited | Construction | 2018 |
| Citadel Homes (RI) Limited | Real estate | 2021 |
| Citadel Homes (RI2) Limited | Real estate | 2023 |
| Citadel Homes (TC) Limited | Financial services | 2021 |
| Citadel MOT Centre North East Limited | Wholesale & retail | 2013 |
| Citation JET Ltd | Transport & logistics | 2019 |
| Citizens Advice Newcastle Limited | Information & communication | 1987 |
| Citron Property Investment Ltd | Real estate | 2026 |
| Citrus Group (NW) Ltd | Construction | 2022 |
| City and Suburb Limited | Real estate | 2024 |
| City Apartment Newcastle Ltd | Hospitality | 2022 |
| City Boiler Cover Ltd | Construction | 2025 |
| City Castle Properties Limited | Construction | 2026 |
| City Church Newcastle | Other services | 2009 |
| City Fire Surrounds Limited | Manufacturing | 2003 |
| City GAS 24 Ltd | Construction | 2024 |
| City Homes Holdings Ltd | Financial services | 2025 |
| City Ladies Networking Limited | Other services | 2020 |
| City Leisure Management Limited | Hospitality | 2023 |
| City Link Executive Limited | Transport & logistics | 2021 |
| City Lofts (N.E.) Limited | Construction | 2003 |
| City Media Group Ltd | Manufacturing | 2023 |
| City North 5 Limited | Construction | 1999 |
| City of GOD Christian Centre | Other services | 2007 |
| City of Newcastle Golf Club Limited (the) | Arts & recreation | 1895 |
| City of Newcastle Golf Club Trading Limited | Arts & recreation | 2016 |
| City of Tomorrow Films Ltd | Information & communication | 2026 |
| City Presence(Newcastle ) Limited | Administrative & support | 2015 |
| City Property (North East) Ltd | Households | 2018 |
| City Rail Support Ltd | Transport & logistics | 2026 |
| City Retreat Salon & Spa Limited | Other services | 2004 |
| City Signs and Display Limited | Manufacturing | 1987 |
| City Sports Group Ltd | Wholesale & retail | 2026 |
| City Taxis (Newcastle) Limited | Transport & logistics | 1979 |
| City Transit (Newcastle) Limited | Transport & logistics | 1987 |
| City Transport (Newcastle) Limited | Transport & logistics | 1994 |
| City Transport Group Ltd | Transport & logistics | 2016 |
| City Travel (Newcastle) Limited | Extraterritorial | 1983 |
| City View (Sunderland) Limited | Real estate | 2014 |
| City Wheels Limited | Transport & logistics | 2024 |
| City's Barbers Limited | Other services | 2017 |
| Citysteps Hotels Limited | Hospitality | 2025 |
| Civilweb Consulting Engineers Limited | Professional & scientific | 2017 |
| CJ Electratech Holdings Ltd | Financial services | 2026 |
| CJ Electratech Limited | Construction | 2006 |
| CJ Recruitment Group Limited | Financial services | 2020 |
| CJ UK Property Limited | Real estate | 2021 |
| CJB + AB Consultants Ltd | Professional & scientific | 2025 |