| Choten Limited | Administrative & support | 2021 |
| Chowdhury Property Solution Ltd | Real estate | 2025 |
| Chown Commercial Limited | Real estate | 2003 |
| Chowns Ltd | Real estate | 2006 |
| Chris Fowkes Distribution Limited | Transport & logistics | 2004 |
| Chris Gates Farriery Limited | Agriculture & fishing | 2024 |
| Chris Hanley & Partners | | 2002 |
| Chris Heywood Physio Limited | Health & social care | 2020 |
| Chris Mcginley Consultancy Limited | Administrative & support | 2018 |
| Chris S Wood Ltd | Arts & recreation | 2022 |
| Chris Simons Ovens Limited | Other services | 2004 |
| Chris Smith Developments Limited | Construction | 1997 |
| Chris Whybrow Sound Limited | Manufacturing | 2017 |
| Chris-D Ltd | Health & social care | 2016 |
| Chrismicc Limited | Health & social care | 2022 |
| Christ Apostolic Church Hisway of Holiness | Other services | 2025 |
| Christ Compassion Network International Limited | Professional & scientific | 2020 |
| Christ United Pentecostal Ministries Liberty House | Other services | 2008 |
| Christa GDP Pharma Ltd | Professional & scientific | 2022 |
| Christchurch (NO1) Limited | Information & communication | 2025 |
| Christchurch Court Residents Company (Northampton) Limited | Households | 1982 |
| Christian Baker Limited | Other services | 2013 |
| Christian Women in Business Leadership (Cwbl) Community Interest Company | Education | 2026 |
| Christine Bell Healthcare Consultancy Limited | Health & social care | 2017 |
| Christobella Deborah ANN Munro Ltd | Extraterritorial | 2025 |
| Christopher Bigsby Limited | Professional & scientific | 2018 |
| Christopher Charles Financial Services Limited | Financial services | 2010 |
| Christopher P Higgins Ltd | Health & social care | 2020 |
| Christopher Stephens Financial Services Limited | Financial services | 2015 |
| Christy & Co. Limited | Manufacturing | 2007 |
| Chrivana Ltd | Information & communication | 2025 |
| Chrk Ltd | Information & communication | 2025 |
| Chroma Conservation Limited | Construction | 2016 |
| Chrome Consultants Limited | Information & communication | 2017 |
| Chrys Speed Trans Ltd | Transport & logistics | 2023 |
| Chrysalis Clothes Limited | Manufacturing | 1985 |
| Chrysalis Digital Consultancy Limited | Information & communication | 2017 |
| Chrysalis Yacht Design Ltd | Extraterritorial | 2023 |
| Chrysellis Limited | Administrative & support | 2012 |
| Chsp Safety Consultancy Limited | Professional & scientific | 2023 |
| CHUCHI3D Ltd | Wholesale & retail | 2026 |
| Chulew Limited | Real estate | 2023 |
| Church 1 Ltd | Real estate | 2026 |
| Church END Field Limited | Agriculture & fishing | 2025 |
| Church of the Holy Sepulchre (Northampton) Restoration Trust | Professional & scientific | 2009 |
| Church Stowe Management Limited | Real estate | 1995 |
| Church View Group Ltd | Professional & scientific | 2020 |
| Church's Factory RTM Company Limited | Households | 2021 |
| Church's Glass & China Stores (Northampton) Limited | Transport & logistics | 1950 |
| Churches Conservation | Arts & recreation | 2013 |
| Churches Conservation Trust Enterprises Limited | Arts & recreation | 2012 |
| Churchouse Boats Limited | Administrative & support | 1998 |
| Churditt Investments Limited | Financial services | 2011 |
| Chwim Ltd | Transport & logistics | 2025 |
| CHX Bloodstock Limited | Agriculture & fishing | 2022 |
| CHY Designs Limited | Extraterritorial | 2023 |
| CHY Homes Limited | Real estate | 2023 |
| CI Aesthetics Academy Ltd | Other services | 2020 |
| CI Building Ltd | Construction | 2019 |
| CI Services Northampton Ltd | Transport & logistics | 2024 |
| CIB Total Solutions Ltd | Construction | 2018 |
| Cibis Services Ltd | Construction | 2026 |
| Cicadas Holdings Ltd | Financial services | 2025 |
| Cicadas Properties Limited | Real estate | 2025 |
| Ciceo Bella Ltd | Transport & logistics | 2010 |
| Cider Dog Ltd | Hospitality | 2024 |
| Ciechol Trans Ltd | Transport & logistics | 2017 |
| CIL Bros Construction Limited | Construction | 2026 |
| CIL Construction Ltd | Construction | 2025 |
| CIL Property Group Ltd | Real estate | 2025 |
| CIM Spedition Ltd | Transport & logistics | 2021 |
| Cimatti Limited | Manufacturing | 2025 |
| Cinar Trading Ltd | Hospitality | 2021 |
| Cindpop Property Limited | Real estate | 2023 |
| Cine Crew Limited | Professional & scientific | 2019 |
| Cine IT Ltd | Information & communication | 2022 |
| Cine-Star Media Ltd | Manufacturing | 2022 |
| Cinnamon Pastry & Coffe Shop Ltd | Hospitality | 2025 |
| Ciobanu Brick Work Ltd | Construction | 2025 |
| Ciobanu Solutions Ltd | Construction | 2026 |
| Ciocio Limited | Construction | 2025 |
| Cioffi and Jones Ltd | Real estate | 2018 |
| Ciontari Transport Ltd | Transport & logistics | 2025 |
| Ciprian Diaconu Ltd | Other services | 2017 |
| Ciprian Ltd | Transport & logistics | 2020 |
| Circe-Mehra Limited | Manufacturing | 2022 |
| Circular Economy Club, C.I.C. | Information & communication | 2018 |
| Circular Economy Industry Training & Qualifications Limited | Other services | 2024 |
| Circular Economy Institute Limited | Other services | 2023 |
| Circular Supply Chain Limited | Wholesale & retail | 2024 |
| Cirencester Orthodontics Limited | Health & social care | 2022 |
| Cirrus Park Management Company Limited | Real estate | 2005 |
| Cirrus Trading Limited | Wholesale & retail | 2001 |
| Cisco Homes Ltd | Construction | 2016 |
| Citizens Advice West Northamptonshire and Cherwell Ltd | Administrative & support | 1999 |
| Citric Ltd | Information & communication | 2006 |
| Citrine Assets Ltd | Real estate | 2020 |
| Citrus Relocation Services Limited | Other services | 2006 |
| City Demolition Services Limited | Construction | 1999 |
| City Face Ltd | Construction | 2020 |