| Civilstruct Recruitment Ltd | Administrative & support | 2025 |
| CJR Property Investments Limited | Real estate | 2010 |
| CKM Property Services Limited | Real estate | 2017 |
| Classic Air Cargo Ltd | Transport & logistics | 2017 |
| Clean Lines Construction Limited | Construction | 2012 |
| Cleanheart Finishing Limited | Financial services | 2023 |
| Clearidge 3110 Limited | Administrative & support | 2021 |
| Clearspace Solution Limited | Professional & scientific | 2025 |
| Clearview Prop Ltd | Real estate | 2023 |
| Clever Accounting Ltd | Professional & scientific | 2021 |
| Clever Clogs Services Limited | Wholesale & retail | 2017 |
| Clinikil Advanced Limited | Administrative & support | 2021 |
| Clive & Louis Investment Properties Ltd | Real estate | 2020 |
| Cmips Management Limited | Households | 2021 |
| CMS Accountancy Services Limited | Information & communication | 1970 |
| Co Start Limited | Administrative & support | 2003 |
| Cocosa Limited | Administrative & support | 2009 |
| Cognireach Marketing Consultancy Ltd | Professional & scientific | 2023 |
| Cognivertex Ltd | Information & communication | 2026 |
| Cogs Administration Services Ltd | Administrative & support | 2020 |
| Coguteac Construction Ltd | Construction | 2023 |
| COL and COW Limited | Administrative & support | 2024 |
| Collondonfurn Limited | Construction | 2025 |
| Company RC Ltd | Construction | 2021 |
| Concept Consulting RMT Limited | Professional & scientific | 2002 |
| Condor Real Estate Limited | Real estate | 2025 |
| Connect Bits Ltd | Other services | 2019 |
| Connect Dream Homes Ltd | Real estate | 2024 |
| Connect MCP Ltd | Information & communication | 2015 |
| Connecting Bridge Ltd | Construction | 2021 |
| Conway Property Investments Ltd | Real estate | 2017 |
| Coodal C.I.C. | Agriculture & fishing | 2023 |
| Coomz Limited | Wholesale & retail | 2017 |
| Coovioo Ltd | Construction | 2023 |
| Copperfield Property Investments Limited | Real estate | 2023 |
| Copycat Consulting Limited | Administrative & support | 2025 |
| Corebiotec Ltd | Wholesale & retail | 2026 |
| Coresolutionforall Limited | Information & communication | 2026 |
| Corian GB Ltd | Manufacturing | 2016 |
| Coronal Accounting Services Limited | Professional & scientific | 2015 |
| Cosmin 07 Ltd | Transport & logistics | 2015 |
| Cosyloft Conversions Limited | Construction | 2014 |
| Cotg Management Company Limited | Households | 2005 |
| Cottage (UK) Ltd | Administrative & support | 2013 |
| Cottenham Farm Ltd | Agriculture & fishing | 2023 |
| Countryline Properties Limited | Real estate | 2017 |
| Courtland Partners Limited | Other services | 2013 |
| Coversure Insurance Services (Leyton) Limited | Financial services | 2001 |
| Coworth Group Limited | Professional & scientific | 2022 |
| CQM First Ltd | Hospitality | 2017 |
| CQM Second Ltd | Hospitality | 2017 |
| CQM Sixth Ltd | Hospitality | 2025 |
| CQM Third Ltd | Hospitality | 2017 |
| CRC Roofing Limited | Construction | 2026 |
| Crown Medical Services Limited | Health & social care | 2015 |
| Crystal Leaf Ltd | Hospitality | 2026 |
| Csolino Cleaning Ltd | Administrative & support | 2023 |
| CSV Property Ltd | Real estate | 2025 |
| Cthulhu Carpet and Upholstery Cleaning Limited | Wholesale & retail | 2017 |
| Cupid Corporation Limited | Real estate | 2022 |
| Cupz Ltd | Wholesale & retail | 2024 |
| Custempo Ltd | Manufacturing | 2024 |
| Cyrus ST Andrews Ltd | Manufacturing | 2023 |
| D & D Property Specialists Limited | Real estate | 2023 |
| D Hunt Holdings Limited | Financial services | 2015 |
| D Sheps Ltd | Water & waste | 2014 |
| D Zaam Property Limited | Real estate | 2023 |
| D&D Smart Lettings Ltd | Real estate | 2025 |
| D&I Drivers Hire Ltd | Transport & logistics | 2014 |
| D&M Management Ltd | Professional & scientific | 2025 |
| D&S Builders Ltd | Construction | 2016 |
| D.H. Engineering Design Limited | Professional & scientific | 2019 |
| D.J First Builders Ltd | Construction | 2023 |
| D.L.Construction Ltd | Administrative & support | 2017 |
| D.R.O.F. Data Limited | Information & communication | 2017 |
| Daata Jewellers UK Limited | Wholesale & retail | 2007 |
| DAF Construct (UK) Limited | Construction | 2017 |
| Dakk Investments Ltd | Real estate | 2021 |
| DAL Market Ltd | Construction | 2019 |
| DAN James Ground Maintenance Ltd | Professional & scientific | 2025 |
| Dand Electrical Ltd | Construction | 2019 |
| Danfilda Ltd | Professional & scientific | 2018 |
| Dani DI Ltd | Administrative & support | 2026 |
| Dannys Site Services Ltd | Administrative & support | 2025 |
| Darius DM Ltd | Real estate | 2015 |
| Darkblessings Ltd | Wholesale & retail | 2022 |
| Dasgupta Holdings Ltd | Information & communication | 2023 |
| DAV Cleanlining Ltd | Construction | 2022 |
| David Rhoda Consulting Ltd | Administrative & support | 2014 |
| Daynight Group of Companies Ltd | Wholesale & retail | 2025 |
| Dazlite Ltd | Information & communication | 2025 |
| DB Estate Management Ltd | Real estate | 2007 |
| DD Acoustics Ltd | Manufacturing | 2026 |
| DD Foodservice Limited | Wholesale & retail | 2011 |
| DE Burgo Limited | Construction | 2002 |
| Deansheppard Ltd | Administrative & support | 2016 |
| Deep Sky Blue Internet Limited | Information & communication | 2014 |
| Dees Collection and Delivery Ltd | Other services | 2024 |
| Dee’S Bespoke DRY Cleaners Ltd | Other services | 2023 |
| Dehi Chai Limited | Hospitality | 2016 |