| CRS NE Ltd | Other services | 2023 |
| CRT Property Ltd | Construction | 2022 |
| Crumblinguk Events Limited | Hospitality | 2025 |
| Crumple Ltd | Information & communication | 2024 |
| Crusader Capital Ltd | Financial services | 2025 |
| Crusader Group Leasing Ltd | Financial services | 2023 |
| Crusader Group Limited | Financial services | 2024 |
| Crusaderenergy Limited | Construction | 2024 |
| Crushing Screening and Engineering Limited | | 1938 |
| Crust NE4 Ltd | Hospitality | 2025 |
| Cruz James Limited | Wholesale & retail | 2025 |
| Crwd Estates Ltd | Real estate | 2024 |
| Cryogenic and Industrial Services Ltd | Transport & logistics | 2025 |
| Crypton Digital Assets Limited | Administrative & support | 2017 |
| Crystal Mount Ltd | Hospitality | 2025 |
| Crystalflight Limited | Real estate | 2006 |
| CRYSTALNAILS4U Ltd | Wholesale & retail | 2010 |
| CS Management Services (NE) Ltd | Construction | 2025 |
| CS Property Management Limited | Households | 2025 |
| CS Simple Tech Solution Ltd | Information & communication | 2025 |
| CSA (Services) Ltd | Other services | 2004 |
| CSD Sealing Systems Limited | Wholesale & retail | 1993 |
| CSH Associates Limited | Households | 2014 |
| CSH Partners Limited | Real estate | 2015 |
| Csi-United Kingdom Limited | Professional & scientific | 2000 |
| Csis-Uk Ltd | Other services | 2011 |
| CSK Property Investment Ltd | Real estate | 2025 |
| CSL Property Investments Ltd | Real estate | 2025 |
| CSM HSE Limited | Professional & scientific | 2024 |
| CSN Consulting Limited Liability Partnership | | 2004 |
| CSR Football LLP | | 2019 |
| Csrf Logistics Ltd | Transport & logistics | 2026 |
| CT Electro Ltd | Wholesale & retail | 2025 |
| CT High Voltage Ltd | Manufacturing | 2026 |
| CT Holdings (North East) Ltd | Real estate | 2024 |
| CT Motors Trades Limited | Wholesale & retail | 2025 |
| CT Support Services Ltd | Administrative & support | 2026 |
| CTA Productions Limited | Information & communication | 2014 |
| CTC Resolutions Limited | Professional & scientific | 2013 |
| Ctrl+Alt+Del Ltd | Information & communication | 2025 |
| Ctrlaltdel Studios Ltd | Professional & scientific | 2018 |
| Cubanos Newcastle Limited | Hospitality | 2022 |
| Cubixio Limited | Information & communication | 2026 |
| Cullen & Davis 1 Limited | Construction | 2017 |
| Cullen & Davis 2 Limited | Construction | 2017 |
| Cullen & Davis Holdings Limited | Financial services | 2017 |
| Cullen Contractors Ltd | Construction | 2009 |
| Cullercoats Corporate Ltd | Professional & scientific | 2019 |
| Cullercoats GIN Company Ltd | Wholesale & retail | 2017 |
| Cult Cards Ltd | Wholesale & retail | 2026 |
| Cultivated Meat Technologies Limited | Manufacturing | 2023 |
| Culture Restaurant and Bar Ltd | Hospitality | 2022 |
| Culture Spawn Limited | Wholesale & retail | 2025 |
| Cultured. North East Limited | Information & communication | 2022 |
| Cultus Lake Enterprises Ltd | Real estate | 2014 |
| Culverdene Nursery Ltd | Health & social care | 2024 |
| Cumbria Accommodation Limited | Hospitality | 2024 |
| Cumbria Employment Limited | Professional & scientific | 2019 |
| Cundall Consulting Limited | Professional & scientific | 2019 |
| Cundall Fire Limited | Professional & scientific | 2019 |
| Cundall Group Limited | Professional & scientific | 2009 |
| Cundall International Limited | Professional & scientific | 2017 |
| Cundall Johnston & Partners LLP | | 2001 |
| Cundall Limited | Professional & scientific | 2005 |
| Cunningham Investments | Financial services | 2022 |
| CUP of Parenting Ltd | Education | 2021 |
| CUP Winners Promotions Ltd | Wholesale & retail | 2016 |
| Cuplete Ltd | Other services | 2024 |
| Cupography Ltd | Wholesale & retail | 2025 |
| Cuppa Chaii (Jesmond) Ltd | Hospitality | 2025 |
| Cuppa Chaii Newcastle City Centre Ltd | Hospitality | 2024 |
| Curious Futures Limited | Hospitality | 2025 |
| Curious Orange Limited | Hospitality | 2018 |
| Curiozity UK Ltd | Wholesale & retail | 2026 |
| Curlew Alternatives Limited | Real estate | 2024 |
| Curlew Capital Ltd | Professional & scientific | 2011 |
| Curlew Communities Limited | Extraterritorial | 2016 |
| Curlew House Associates Limited | Professional & scientific | 2009 |
| Curry Bazar (NE) Ltd | Hospitality | 2017 |
| Curry HUT (Washington) Ltd | Hospitality | 2016 |
| Curtis Gabriel Corporation Limited | Administrative & support | 2012 |
| Cush Limited | Information & communication | 2026 |
| Custom Fitout Group Ltd | Construction | 2026 |
| Custom International Sourcing Limited | Administrative & support | 2007 |
| Custom Lids Limited | Wholesale & retail | 2002 |
| Custom Mania GB Ltd | Wholesale & retail | 2025 |
| Custom Vending Ltd | Hospitality | 2024 |
| Customconversions Limited | Construction | 2022 |
| Customer Logistics NE Ltd | Transport & logistics | 2024 |
| Customersure Ltd | Information & communication | 2010 |
| Customise IT NOW 2024 Ltd | Wholesale & retail | 2024 |
| CUT Klean Ltd | Other services | 2017 |
| Cute AS Cakes Ltd | Hospitality | 2026 |
| Cute CUT Limited | Other services | 2020 |
| Cutpay Merchant Services Limited | Administrative & support | 2015 |
| Cutsolutions Ltd | Information & communication | 2019 |
| Cuttersmate CM Ltd | Manufacturing | 2026 |
| Cutting Edge Projects Limited | Wholesale & retail | 2006 |
| Cutting IT Fine Warfield Ltd | Other services | 2005 |
| Cuwin Ltd | Real estate | 2025 |