| Clear IT Recruitment Limited | Administrative & support | 2010 |
| Clear Light International Ltd | Professional & scientific | 2015 |
| Clear Path Block Chain Limited | Information & communication | 2025 |
| Clear Path Care Advisory Ltd | Professional & scientific | 2026 |
| Clear Steps Healthcare Limited | Administrative & support | 2026 |
| Clearance UK Limited | Wholesale & retail | 2019 |
| CLEARANCE4LESS Norfolk Ltd | Water & waste | 2023 |
| Cleargrid Energy Ltd | Wholesale & retail | 2016 |
| Clearpath Commercial Limited | Financial services | 2025 |
| Clearsteps Recruitment Limited | Health & social care | 2025 |
| Clearwater (Norwich) Limited | Professional & scientific | 2005 |
| Clearwater Anglia Limited | Professional & scientific | 2012 |
| Clearwater Software Limited | Information & communication | 2026 |
| Clebets Management Limited | Professional & scientific | 2025 |
| Clement Court (HR) Limited | Real estate | 2022 |
| Clere House Management Company Limited | Households | 2017 |
| Clerkin Civils Ltd | Construction | 2013 |
| Clerkin Group Ltd | Administrative & support | 2016 |
| Clerkin Plant Hire Ltd | Administrative & support | 2013 |
| Clever Things for the Web Limited | Information & communication | 2025 |
| Clever Voice Limited | Information & communication | 2010 |
| Click Competitions Limited | Wholesale & retail | 2020 |
| Click ST Andrews Limited | Real estate | 2018 |
| Click World Ltd | Hospitality | 2014 |
| Click-Relocations Limited | Real estate | 2025 |
| Clickers Archery Ltd | Manufacturing | 2002 |
| Clicks Digital Printing Ltd | Manufacturing | 2017 |
| Clickzilla Ltd | Professional & scientific | 2026 |
| Client Agent Solutions Limited | Information & communication | 2026 |
| Client Loop Ltd | Information & communication | 2022 |
| Clientele Solutions Limited | Professional & scientific | 2024 |
| Cliff Hill Capital Limited | Real estate | 2021 |
| Cliff Top Properties Limited | Real estate | 2018 |
| Cliffe & Co. Ltd | Professional & scientific | 2025 |
| Clifford Event Management Ltd | Hospitality | 2018 |
| Clifftop Holidays Limited | Real estate | 2020 |
| Climate Museum UK CIC | Professional & scientific | 2019 |
| Climatic Extrusions Limited | Construction | 1961 |
| Climb Competitions Ltd | Arts & recreation | 2025 |
| Clinical Response Group CIC | Administrative & support | 2024 |
| Clinical Task Systems Limited | Information & communication | 2017 |
| Clinical Trials Consultancy (CTS) Limited | Professional & scientific | 2017 |
| Clipeum IT Group Limited | Information & communication | 1989 |
| Clips Barber Ltd | Other services | 2026 |
| CLJ Cleaning Ltd | Administrative & support | 2023 |
| Clmbh Ltd | Hospitality | 2025 |
| CLN Event Consulting Ltd | Professional & scientific | 2024 |
| CLO Insulation Limited | Financial services | 2019 |
| Clockwork Barbers Ltd | Other services | 2025 |
| Clos Norfolk Limited | Real estate | 2025 |
| Closed Secure Storage Ltd | Transport & logistics | 2020 |
| Cloud 9 Candyfloss Ltd | Wholesale & retail | 2025 |
| Cloud 9 Kitchen Ltd | Hospitality | 2024 |
| Cloud Clarity Consulting Ltd | Information & communication | 2017 |
| Cloud Coffee Bar Ltd | Manufacturing | 2024 |
| Cloud Infinity Projects Limited | Professional & scientific | 2013 |
| Cloudeq Limited | Information & communication | 2022 |
| Cloudscope Ltd | Administrative & support | 2016 |
| Cloudy Holdings Ltd | Extraterritorial | 2022 |
| Clover Biopharmaceuticals UK Ltd | Professional & scientific | 2021 |
| Clover Fencing & Landscaping Ltd | Professional & scientific | 2026 |
| Cloverfield Homes Limited | Construction | 2013 |
| Cloverfield Number 1 Residents Association Limited | Households | 1990 |
| Cloverleaf Advisory Ltd | Other services | 2020 |
| Clovers Inn Limited | Hospitality | 2021 |
| Clovian Limited | Professional & scientific | 2008 |
| Clozevip Ltd | Administrative & support | 2023 |
| CLS Norwich Limited | Real estate | 2019 |
| Club Monster Mayhem Ltd | Education | 2018 |
| Club Walter Ltd | Wholesale & retail | 2025 |
| Clubpst Limited | Hospitality | 2018 |
| Clustr Holdings Ltd | Financial services | 2022 |
| Clustr Technology Ltd | Information & communication | 2022 |
| Clyffe Management Limited | Real estate | 2016 |
| CM 1 (Norwich) Limited | Real estate | 2023 |
| CM Agriculture Limited | Agriculture & fishing | 2011 |
| CM Laurie Ltd | Manufacturing | 2016 |
| CM Plant Limited | Administrative & support | 2002 |
| CMB Multimedia Limited | Information & communication | 2015 |
| Cmbq Ltd | Real estate | 2021 |
| CMC Development Holdings Ltd | Construction | 2018 |
| CMC Retirement Living Group Ltd | Health & social care | 2017 |
| CMD Transport Ltd | Transport & logistics | 2021 |
| CME Premium Limited | Administrative & support | 2024 |
| CMG Contractors Ltd | Agriculture & fishing | 2021 |
| CMI Print Services Ltd | Manufacturing | 2010 |
| Cml-Engsolutions Ltd | Professional & scientific | 2021 |
| Cmos Clinical Services Limited | Health & social care | 2025 |
| CMS Installations Norwich Ltd | Construction | 2023 |
| CMT Industrial Powder Coaters Ltd | Manufacturing | 2004 |
| CMW Ventilation Ltd | Construction | 2019 |
| CN Composites Ltd | Wholesale & retail | 2025 |
| CN Mediaverse Limited | Professional & scientific | 2026 |
| CN Plumbing & Heating Limited | Construction | 2012 |
| CN Software Ltd | Information & communication | 2015 |
| CN Solutions Limited | Information & communication | 2007 |
| CNB Consultants Ltd | Construction | 2010 |
| CNB Holdings Limited | Financial services | 2015 |
| CNC Precision Engineering Services Ltd | Manufacturing | 2006 |
| CNC Service Solutions Ltd | Administrative & support | 2012 |