| Conors Car Centre Ltd | Wholesale & retail | 2014 |
| Construction & Consulting Ltd | Construction | 2018 |
| Construction BUD Ltd | Construction | 2025 |
| Consulting Engineers UK Board Ltd | Other services | 2026 |
| Context First AI Limited | Information & communication | 2026 |
| Conti DI Casole Ltd | Real estate | 2020 |
| Contract Bathroom Supplies Ltd | Wholesale & retail | 2011 |
| Contract Energy Management Limited | Construction | 1993 |
| Convexa AI Ltd | Information & communication | 2025 |
| Cookedbyrowe Ltd | Hospitality | 2024 |
| Cookes Property Services Limited | Wholesale & retail | 2008 |
| Coonell Construction Ltd | Construction | 2013 |
| Coordeck Technologies Ltd | Information & communication | 2024 |
| Core Multiprofit Ltd | Wholesale & retail | 2024 |
| Corp Collab Limited | Real estate | 2022 |
| Corposostenibile LLP | | 2025 |
| Corte Real Partners Ltd | Administrative & support | 2024 |
| Cost Choice Ltd | Wholesale & retail | 2025 |
| Country Pavilions Limited | Wholesale & retail | 2019 |
| Course IS Clear Ltd | Information & communication | 2019 |
| Courtlands Avenue Ltd | Construction | 2023 |
| CP Business Support Services Ltd | Administrative & support | 2017 |
| CP Digital Consulting Ltd | Information & communication | 2018 |
| Cranbenn Limited | Professional & scientific | 2017 |
| Creative Design & Build Ltd | Construction | 2020 |
| Creative Mediapulse Technologies Limited | Administrative & support | 2025 |
| Creative Powerz Ltd | Arts & recreation | 2010 |
| Creative Video Limited | Information & communication | 2018 |
| Creative Video Productions Limited | Information & communication | 1989 |
| Creative Vision Finance Limited | Financial services | 2020 |
| Credent Global Finance Limited | Professional & scientific | 2017 |
| Credent Management Consultancy Limited | Financial services | 2019 |
| Credent Property Advisory Limited | Real estate | 2017 |
| Crehan Consultancy Ltd | Public administration | 2012 |
| Crew Brentford Ltd | Other services | 2025 |
| Crews Control Limited | Wholesale & retail | 2016 |
| Crimson Red Contracting UK Limited | Construction | 2016 |
| Crissy Flake Consulting Ltd | Administrative & support | 2020 |
| CRM Angels Ltd | Information & communication | 2011 |
| Crowdgold Limited | | 1986 |
| Crown Commercial Services Limited | Extraterritorial | 2006 |
| Crown UK Holdco Limited | Financial services | 2017 |
| Croydon Traders Ltd | Wholesale & retail | 2020 |
| Cruthaich Ltd | Professional & scientific | 2021 |
| Crystal Universe Ltd | Arts & recreation | 2026 |
| Crystaline Communications Limited | Information & communication | 2006 |
| CS (Brixton) Limited | Information & communication | 2005 |
| CS (Exeter) Limited | Information & communication | 2005 |
| CS Interiors (UK) Limited | Manufacturing | 2008 |
| Ctrl Forward Ltd | Information & communication | 2023 |
| Cuber Limited | Information & communication | 2022 |
| Cubes Tech Limited | Information & communication | 2015 |
| Cubicae Ltd | Construction | 2025 |
| Culture Press Limited | Information & communication | 2022 |
| Cumulus Clouds Limited | Real estate | 2022 |
| Curra Ltd | Information & communication | 2026 |
| Curva Grande Ltd | Professional & scientific | 2020 |
| Curzen GRP Ltd | Administrative & support | 2022 |
| Curzen Ltd | Information & communication | 2022 |
| Curzen Research Ltd | Professional & scientific | 2022 |
| Curzen Services Ltd | Professional & scientific | 2022 |
| Custom Option Investments Ltd | Construction | 2023 |
| Customanuals Ltd | Other services | 2021 |
| Cutter and Squidge Ltd | Manufacturing | 2012 |
| Cwti Ltd | Wholesale & retail | 2023 |
| Cybervault Innovations and Technologies Private Ltd | Information & communication | 2023 |
| Cygnet Call Centre Ltd | Administrative & support | 2000 |
| Cyphene Limited | Professional & scientific | 2016 |
| D & J Real Estate Limited | Real estate | 2021 |
| D+Bulla Consultants Limited | Professional & scientific | 2005 |
| D-Loc LLP | | 2023 |
| DAB Tutoring Limited | Education | 2022 |
| Daily Dazzle London Ltd | Wholesale & retail | 2025 |
| Daisy Applications Limited | Information & communication | 2018 |
| Dalal Travels Ltd | Administrative & support | 2016 |
| Dalrigh Consultancy Ltd | Other services | 2021 |
| DAN DE Lord Consultancy Ltd | Professional & scientific | 2023 |
| Daniel Sultan Consultancy Ltd | Professional & scientific | 2024 |
| Danielli Estates Ltd | Real estate | 2017 |
| Danubian Ltd | Information & communication | 2021 |
| Daren Sellwood Ticketing Limited | Arts & recreation | 2026 |
| Darkbluemoon Ltd | Wholesale & retail | 2024 |
| Darling Maple Ltd | Other services | 2024 |
| Darshana Enterprises Ltd | Hospitality | 2026 |
| Dart IT Limited | Information & communication | 2010 |
| Data Centre Consultants Ltd | Wholesale & retail | 2015 |
| Datashaka Limited | Professional & scientific | 2010 |
| Datscom Solutions Ltd | Information & communication | 2024 |
| David Pereira Studio Limited | Information & communication | 2017 |
| Davidson Courier Services Ltd | Transport & logistics | 2009 |
| Dawn Books Ltd | Wholesale & retail | 2023 |
| Day Aggregates Limited | Extraterritorial | 1986 |
| Day Contracting Limited | Extraterritorial | 1999 |
| Day's Bar and Restaurant Ltd | Hospitality | 2019 |
| Dbmm Properties Ltd | Real estate | 2020 |
| DC Lifestyle Limited | Administrative & support | 2010 |
| DC Plant & Equipment Ltd | Construction | 2026 |
| DCF Capital Ltd | Financial services | 2024 |
| DCX Consulting Ltd | Professional & scientific | 2026 |
| Ddays Group Limited | Transport & logistics | 2020 |