| Cult Couture Limited | Wholesale & retail | 2024 |
| Cultura Consulting Limited | Professional & scientific | 2019 |
| Cultura Creative Limited | Professional & scientific | 2021 |
| Culture Crossroads | Education | 2010 |
| Culturevist Ltd | Information & communication | 2015 |
| Cuma EDE Ltd | Health & social care | 2014 |
| Curate Auto Group Ltd | Wholesale & retail | 2024 |
| Curcumin Ltd | Hospitality | 2022 |
| Curio UK Limited | Wholesale & retail | 2005 |
| Curiosity Events CIC | Education | 2025 |
| Curious Directive | Arts & recreation | 2010 |
| Curious Directive Enterprises Ltd | Hospitality | 2022 |
| Curious Spark Ltd | Education | 2019 |
| Curley Construction (Cambridge) Limited | Real estate | 2011 |
| Curly Dog Films Ltd | Professional & scientific | 2024 |
| Curo Group Ltd | Administrative & support | 2025 |
| Curry Club Limited | Hospitality | 2012 |
| Curry O City Ltd | Hospitality | 2024 |
| Curry Republic Henley Limited | Hospitality | 2014 |
| Currybox Castle Quarter Ltd | Hospitality | 2022 |
| Cursitor Property Company Limited | Professional & scientific | 1951 |
| Curtain Road Developments 27 Limited | Energy | 2021 |
| Curtainhub Ltd | Manufacturing | 2023 |
| Curtis & Wright Construction Limited | Construction | 2018 |
| Curtis Armes Limited | Manufacturing | 2017 |
| Curva Club Ltd | Information & communication | 2025 |
| Curve Motion Bury Ltd | Arts & recreation | 2025 |
| Curzon House Residents Association (Norwich) Ltd | Real estate | 1982 |
| Custance & SON Ltd | Construction | 2004 |
| Custodian Golf Limited | Administrative & support | 2024 |
| Custom Built Ebikes Ltd | Wholesale & retail | 2020 |
| Custom Colours Limited | Wholesale & retail | 2000 |
| Custom Fabrication Services Ltd | Manufacturing | 2019 |
| Custom Vibez Limited | Administrative & support | 2025 |
| CUT the Mustard Animation Ltd | Professional & scientific | 2019 |
| Cutane Ltd | Health & social care | 2023 |
| Cutbush Farm Ltd | Real estate | 2022 |
| Cutlers Hill Holdings Limited | Financial services | 2021 |
| Cutprice Furniture and Carpets Ltd | Wholesale & retail | 2018 |
| Cutter Shop Limited | Wholesale & retail | 2009 |
| Cutting Edge Composites Technology Limited | Professional & scientific | 2018 |
| Cutting Edge Medical Education Limited | Education | 2014 |
| Cutty Sark Logistics Ltd | Transport & logistics | 2021 |
| CVB Design Consultancy Ltd | Administrative & support | 2023 |
| CVG Recruitment Limited | Administrative & support | 2018 |
| CW Breakfast & Lunch Ltd | Hospitality | 2019 |
| CW Harmer & SON Limited | Construction | 2006 |
| CW Intl Development Ltd | Wholesale & retail | 2022 |
| CWG (Norwich) Limited | Construction | 2018 |
| CWSQ2 Ltd | Real estate | 2018 |
| CXF Limited | Wholesale & retail | 2017 |
| Cyan Renew (UK) Holdings Limited | Financial services | 2024 |
| Cyberagility Ltd | Information & communication | 2016 |
| Cyberpan Support Services Ltd | Professional & scientific | 2018 |
| Cyberscale Ltd | Information & communication | 2002 |
| Cybersoftec Limited | Information & communication | 2024 |
| Cyborg Interfaces Ltd | Professional & scientific | 2025 |
| Cycad Consulting Ltd | Information & communication | 2016 |
| Cycl. Studios Ltd | Hospitality | 2026 |
| Cycle Medic Norwich Ltd | Extraterritorial | 2024 |
| Cygnet Homes (Norfolk) Ltd | Construction | 2017 |
| Cygnus & Click Ltd | Information & communication | 2019 |
| Cyrock Partners Ltd | Professional & scientific | 2020 |
| Cyversa Ltd | Professional & scientific | 2015 |
| Czarnowski Limited | Extraterritorial | 2018 |
| Czepeku Ltd | Arts & recreation | 2020 |
| D & a Architectural Limited | Construction | 2010 |
| D & C Murrell Limited | Construction | 2007 |
| D & D Pest Control Limited | Administrative & support | 2026 |
| D & F Mccarthy Holdings Limited | Financial services | 2019 |
| D & L Fixings Limited | Wholesale & retail | 2010 |
| D & M Hickling Properties Ltd | Construction | 2002 |
| D & N (Holdings) Limited | Construction | 2007 |
| D & P Healthcare Solutions Ltd | Administrative & support | 2016 |
| D & R Construction Developments Limited | Administrative & support | 2002 |
| D & S Developments (East Anglia) Ltd | Construction | 2022 |
| D & W Properties Ltd | Real estate | 2004 |
| D a Culling Scrap Metals Ltd. | Water & waste | 2017 |
| D a L Lawson Ltd | Wholesale & retail | 2024 |
| D and H Distribution Limited | Wholesale & retail | 2020 |
| D and S Costumes Ltd | Arts & recreation | 2021 |
| D B Financial Management Limited | Financial services | 2010 |
| D B Wright Pipework Ltd | Manufacturing | 2007 |
| D Bros Ltd | Wholesale & retail | 2019 |
| D Burdett Mortgages Ltd | Financial services | 2025 |
| D C Building Services Limited | Construction | 2015 |
| D C Developments (Engineering) Limited | Manufacturing | 1994 |
| D C Developments (Norfolk) Limited | Real estate | 2017 |
| D C Enterprises Norfolk Ltd | Construction | 2023 |
| D C Hinton Limited | Financial services | 2026 |
| D C Richmond Roofing Limited | Construction | 2006 |
| D C West Farms (Suffolk) Limited | Agriculture & fishing | 2015 |
| D C Williams Limited | Professional & scientific | 2010 |
| D Casey Limited | Other services | 2003 |
| D Core Ltd | Wholesale & retail | 2026 |
| D Farrow Plumbing & Bathrooms Ltd | Construction | 2020 |
| D Flatt Couriers Limited | Transport & logistics | 2026 |
| D G Harvesters Limited | Manufacturing | 2011 |
| D Gallop Ltd | Construction | 2023 |
| D Gill & Co Ltd | Construction | 2014 |