| Cheese and Bees Ltd | Hospitality | 2024 |
| Chenery Taylor Management Company Ltd | Financial services | 2019 |
| Cherry PIE Cottages Limited | Construction | 2009 |
| Cherry Tree Academy Trust Marham | Education | 2014 |
| Chill OUT Solutions Limited | Transport & logistics | 2006 |
| Chilli HUT Terrington Ltd | Hospitality | 2025 |
| Chilli Masters Ltd | Hospitality | 2025 |
| Chilver House Lane Management Ltd | Households | 2021 |
| Chilver House Stables Limited | Agriculture & fishing | 2016 |
| Chisther Medical Services Ltd | Health & social care | 2025 |
| CHM Builders Limited | Construction | 2002 |
| Chop & Chisel Limited | Construction | 2015 |
| Chris Dagless Property Limited | Real estate | 2026 |
| Chris Meekins Ruminant Nutrition Limited | Wholesale & retail | 2004 |
| Church Barns Management Company Ltd | Real estate | 2007 |
| Church Farm (North Wootton) Limited | Agriculture & fishing | 2022 |
| Church Farm 4X4 LLP | | 2022 |
| Church Mews (Wisbech) Management Ltd | Households | 2023 |
| Church View Management Company (Wretton) Limited | Households | 1992 |
| Churchill Court (Bishopspark) Residents Association Limited | Households | 1992 |
| Cimton Limited | Hospitality | 2008 |
| Cipriano Transport Ltd | Transport & logistics | 2022 |
| Cirrus Impington Limited | Real estate | 2021 |
| Cirrus Land Limited | Real estate | 2015 |
| Cito Property Development Limited | Construction | 2019 |
| City Cosmetic Clinic Limited | Extraterritorial | 2012 |
| Cityscape Management (UK) Limited | Real estate | 2010 |
| CJ Personnel Ltd | Administrative & support | 2024 |
| CJ Ventures Ltd | Real estate | 2015 |
| CJC Builders Ltd | Construction | 2026 |
| CJF Property Holdings Ltd | Real estate | 2021 |
| CJG Flooring Limited | Construction | 2025 |
| CJL Site Management Ltd | Construction | 2025 |
| CJR (Projects) Limited | Construction | 2021 |
| CJR (Sales) Limited | Construction | 2007 |
| CJR Holdings (Norfolk) Ltd | Financial services | 2025 |
| CJR Site Services Ltd | Construction | 2025 |
| CK Engineering & Agriculture Ltd | Manufacturing | 2026 |
| CK Horticulture Limited | Administrative & support | 2023 |
| CK Lock Ltd | Real estate | 2025 |
| Ckbba Limited | Health & social care | 2023 |
| CL Global Group Ltd | Education | 2015 |
| Clan Trust Limited | Other services | 1987 |
| Clanpress (King's Lynn) Limited | Manufacturing | 1975 |
| Clarence Court (Hunstanton) Management Limited | Real estate | 1973 |
| Clareo Consulting Ltd | Information & communication | 2022 |
| Clarity Property Investment Limited | Real estate | 2017 |
| Clay Homes (Norfolk) Limited | Construction | 2022 |
| Clean Tech Norfolk Ltd | Administrative & support | 2007 |
| Clearchoice Living Ltd | Real estate | 2021 |
| Clearsol Renewables Ltd | Construction | 2024 |
| Clicksolut Ltd | Wholesale & retail | 2024 |
| Clientflow Systems Ltd | Information & communication | 2026 |
| Cliff Parade Management Company Limited | Real estate | 2011 |
| Clifford Cross Auctions Limited | Wholesale & retail | 2001 |
| Climb Higher Limited | Arts & recreation | 2011 |
| Clingo Electrical Services Ltd | Construction | 2026 |
| Clinical Inorganics Limited | Professional & scientific | 2011 |
| Clinimax Limited | Health & social care | 2025 |
| Cloud Scale Consulting Limited | Information & communication | 2015 |
| CMA Facility Limited | Construction | 2025 |
| CMG Property Developments Ltd | Administrative & support | 2017 |
| Cmra Ltd | Arts & recreation | 1997 |
| CMS Design & Build Ltd | Construction | 2021 |
| CMS Food Group - the Munchbox Ltd | Hospitality | 2025 |
| CMS Food Group Liquor and Loaded Ltd | Hospitality | 2025 |
| CMS Food Group Waffleopolis Ltd | Hospitality | 2025 |
| CNB Stainless Ltd | Manufacturing | 2019 |
| CNC Science Limited | Professional & scientific | 2024 |
| Coach House Health Care Limited | Health & social care | 2020 |
| Coastal Communications Ltd | Wholesale & retail | 2020 |
| Coastal Red Limited | Transport & logistics | 2013 |
| Cobb Thatch Rentals Ltd | Real estate | 2020 |
| Cobra Campers Limited | Wholesale & retail | 2022 |
| Cobra Vehicle Services Limited | Wholesale & retail | 2022 |
| Cocker Developments Limited | Construction | 2025 |
| Codelogix Ltd | Information & communication | 2010 |
| Cognitise Consulting Limited | Health & social care | 2016 |
| Coherent Communications Limited | Professional & scientific | 2017 |
| Coin Collector UK Ltd | Wholesale & retail | 2023 |
| Coldharbour Alpha Limited | Administrative & support | 2026 |
| Coldstorrs Limited | Construction | 2003 |
| Colemed Limited | Health & social care | 2005 |
| Colin Dawson Windows Limited | Wholesale & retail | 1990 |
| Colman Plumbing and Heating Ltd | Construction | 2022 |
| Colthorpe Consultancy Ltd | Information & communication | 2023 |
| Colville House Apartments Residents Management Limited | Real estate | 2004 |
| Commercial and Marine Comms Limited | Agriculture & fishing | 2003 |
| Commercial Vehicle Conversions UK Ltd | Manufacturing | 2023 |
| Common Consultancy Limited | Other services | 2019 |
| Common Way Limited | Real estate | 1987 |
| Compass Handbooks Limited | Information & communication | 2016 |
| Compass Publications Limited | Information & communication | 1992 |
| Compassion Connect Limited | Information & communication | 2026 |
| Complete & Utter Limited | Hospitality | 2024 |
| Complete Metal Services (East Anglia) Limited | Wholesale & retail | 2007 |
| Comserve Technology Solutions Limited | Wholesale & retail | 2014 |
| Concept Network Design Ltd | Professional & scientific | 2024 |
| Conectar Consultancy Services Limited | Administrative & support | 2015 |
| Congham Hall Limited | Hospitality | 2011 |