| Co Products Limited | Wholesale & retail | 2017 |
| Coachgate Events Ltd | Hospitality | 2017 |
| Coast to Coast Ventures Limited | Hospitality | 2021 |
| Coastal Carpenters Ltd | Construction | 2018 |
| Coastal Luxury Lets UK Ltd | Real estate | 2026 |
| Coastal Scrap and Auto Salvage Limited | Wholesale & retail | 2018 |
| Coastline Seafoods Limited | Manufacturing | 2007 |
| COB Security Ltd | Administrative & support | 2023 |
| Coba Design Studio Ltd | Professional & scientific | 2024 |
| Cobblestone Cafe Ltd | Hospitality | 2025 |
| Cobra Energy Services Limited | Professional & scientific | 2016 |
| Code AU Fait Ltd | Wholesale & retail | 2016 |
| COE Fabrications Limited | Manufacturing | 2005 |
| Coffee in the Park Grimsby Ltd | Hospitality | 2025 |
| Coffee on the Park Ltd | Hospitality | 2024 |
| Coggan Electrical Services Ltd | Wholesale & retail | 2026 |
| Coglec Ltd | Construction | 2023 |
| Cognumen Ltd | Professional & scientific | 2026 |
| Cold Clean UK Limited | Administrative & support | 2019 |
| Coldlane (New Waltham) Management Company Limited | Households | 2013 |
| Coldstar Air Conditioning Ltd | Extraterritorial | 2020 |
| Coldstar Group Ltd | Extraterritorial | 2020 |
| Coldstar Refrigeration Ltd | Manufacturing | 2012 |
| Cole Williams Software Limited | Information & communication | 2013 |
| Coleby Holdings Unlimited | Financial services | 2016 |
| Colefab Limited | Construction | 2025 |
| Colehill Electrical Ltd | Construction | 2012 |
| Coleman Joinery & Building Contractors Ltd | Construction | 2021 |
| Collective Property Investments Ltd | Real estate | 2018 |
| Collingwoods Funeral Services Ltd | Other services | 2016 |
| Collinson Entertainments Ltd | Hospitality | 2009 |
| Collis Builders Limited | Construction | 2021 |
| Colour Outside the Lines Community Interest Company | Other services | 2024 |
| Columbus Quay Property Ltd | Construction | 2022 |
| Combat Sports Hygiene Ltd | Wholesale & retail | 2024 |
| Commercial Refurbishment & Consultancy Ltd | Construction | 2018 |
| Community Fitness Network Limited | Other services | 2019 |
| Community Press Office Ltd. | Information & communication | 2005 |
| Compare Quality Care Limited | Information & communication | 2018 |
| Compare the Tyre Ltd | Administrative & support | 2017 |
| Compass Damp Proofing (Lincs) Ltd | Administrative & support | 2021 |
| Compleat Kitchen Ltd | Hospitality | 2019 |
| Complete Energy (Grimsby) Ltd | Construction | 2025 |
| Complete Paintworx Ltd | Construction | 2024 |
| Complete Physique Limited | Arts & recreation | 2015 |
| Complete Rope Access Solutions Limited | Administrative & support | 2015 |
| Complete Site Inspection Ltd | Education | 2014 |
| Compliant Safety UK Ltd | Public administration | 2018 |
| Concept Digital Services (UK) Ltd | Professional & scientific | 2012 |
| Cone Seafoods Limited | Manufacturing | 2024 |
| Conesandbones Ltd | Wholesale & retail | 2025 |
| Config Limited | Professional & scientific | 2015 |
| Configure IT Services Ltd | Information & communication | 2024 |
| Conlab Ltd | Information & communication | 2025 |
| Conmat Ltd | Construction | 2025 |
| Connair Plant & Haulage Limited | Construction | 2010 |
| Constellation Cold Logistics UK Holdings Limited | Administrative & support | 2020 |
| Constellation Cold Logistics UK Midco Limited | Administrative & support | 2020 |
| Consult With Confidence Ltd | Information & communication | 2016 |
| Consulting Research Ltd | Wholesale & retail | 2018 |
| Continental Food Group Limited | Wholesale & retail | 2015 |
| Contour Security Limited | Administrative & support | 2017 |
| Contractorr Ltd | Construction | 2025 |
| Contrimex (Overseas) Limited | Wholesale & retail | 1994 |
| Controlled Building Measures (Holdings) Limited | Professional & scientific | 2009 |
| Cook's Equestrian Limited | Agriculture & fishing | 2023 |
| Cooke Stanway Wainwright Limited | Hospitality | 2015 |
| Cooks Group Ltd | Wholesale & retail | 2018 |
| Cool Beans Coffee Bar Ltd | Hospitality | 2018 |
| Cool Comfort Limited | Construction | 2024 |
| Cool Energy Holding Limited | Manufacturing | 2017 |
| Cool Waves Swim School Ltd | Arts & recreation | 2021 |
| Coolseal Asset Management Limited | Administrative & support | 2013 |
| Cooper Site Services Ltd | Administrative & support | 2017 |
| Coopers Painting Contractors Limited | Construction | 2007 |
| Coopers Removals Ltd | Other services | 2016 |
| Coopers Tyre Services Limited | Wholesale & retail | 2020 |
| Copes Readymix Limited | Manufacturing | 2009 |
| Copier Systems Management Limited | Other services | 2017 |
| Copper Beech Court (Scartho) Management Ltd | Households | 2025 |
| Copper Beech Court Development Ltd | Construction | 2024 |
| Copper Beech Management Company (Lincoln) Ltd | Households | 2016 |
| Coppergate SA Developments Ltd | Hospitality | 2021 |
| Copywriting Limited | Administrative & support | 2002 |
| COR Lifts Limited | Manufacturing | 2018 |
| Corbelo Group Ltd | Real estate | 2020 |
| Cordelia Lets Limited | Real estate | 2012 |
| Cordells (Grimsby) Limited | Manufacturing | 2013 |
| Core Care Links Limited | Health & social care | 2010 |
| Core Centre of Performing Arts Ltd | Education | 2021 |
| Core Chiropractic Ltd | Health & social care | 2024 |
| Core CM Solutions Limited | Information & communication | 2024 |
| Core Drivers Ltd | Administrative & support | 2017 |
| Core Holding Group Limited | Real estate | 2016 |
| Cormac Management Company Limited | Households | 2023 |
| Corner Shop Supermarket Ltd | Wholesale & retail | 2019 |
| Cornwall Tech Ltd | Manufacturing | 2020 |
| Coronation Grill House Ltd | Hospitality | 2025 |
| Corporate Safety Training Services Limited | Professional & scientific | 2009 |
| Corrine Kirstie Design Ltd | Professional & scientific | 2024 |