| Commonside Capital Investments Limited | Hailsham | 2025 |
| Commonwealth A.C.T Limited | City Of London | 2025 |
| Commonwealth Disaster Management Agency Limited | London | 2003 |
| Commonwealth Foundation | Cardiff | 2021 |
| Commonwealth Games (Scotland) Endowment Fund | Glasgow | 2006 |
| Commonwealth Group Holdings Ltd | Durham | 2025 |
| Commonwealth Group Investments Ltd | Durham | 2025 |
| Commonwealth Group Real Estate Ltd | Durham | 2025 |
| Commonwealth Group Services Ltd | Durham | 2025 |
| Commonwealth Holdings Limited | Ilford | 2025 |
| Commonwealth Insurance Forum Ltd | London | 2019 |
| Commotex Holdings Limited | Hinckley | 2017 |
| Commprop Link Ltd | Belfast | 2021 |
| Commrai Commercial Limited | Birmingham | 2019 |
| Comms Capital Holdings Ltd | Chelmsford | 2020 |
| COMMS365 Holdings Limited | Reading | 2024 |
| Commsense FX Limited | London | 2019 |
| Commshare Ltd. | Sidcup | 1998 |
| Commstack Holdings Limited | London | 2025 |
| Commsure Ltd | London | 2022 |
| Commtech Group Limited | Stoke On Trent | 2021 |
| Commun IQ Invest Ltd | Leeds | 2015 |
| Communicate Group Limited | London | 2023 |
| Communication Activities and Services Global Group Ltd | Cardiff | 2024 |
| Communicators Training Associates Holdings Limited | Darlington | 2022 |
| Communicorp UK Digital Investments Limited | Chester | 2020 |
| Communities Insurance Brokers Community Interest Company | Cheltenham | 2014 |
| Community Advancement Fund C.I.C. | Harrow | 2013 |
| Community Brands UK Limited | Leicester | 2017 |
| Community Build (Maidenhead) Community Interest Company | Maidenhead | 2024 |
| Community Capital Finance Ltd | Reading | 2024 |
| Community Chest Limited | Coalville | 2015 |
| Community Directions Ltd | Ripley | 2023 |
| Community Enable Funding Limited | London | 2025 |
| Community Fibre Holdings Limited | London | 2021 |
| Community Finance Company 1 PLC | London | 2010 |
| Community Finance Ltd | Hounslow | 2024 |
| Community First Trading Limited | Devizes | 2013 |
| Community Ground Source Heating Limited | Bury St Edmunds | 2024 |
| Community Group Limited | Hillmorton | 2018 |
| Community Health & Medicine Ltd | Bristol | 2015 |
| Community Health and Eyecare (Holdings) Limited | Preston | 2018 |
| Community Health South Elmsall Limited | Leeds | 2024 |
| Community Holdings Ltd | Scarborough | 2022 |
| Community Investment Facility 2 Limited | London | 2023 |
| Community Investment Facility Limited | London | 2017 |
| Community Lettings Management Group Ltd | Liverpool | 2026 |
| Community Lottery Schemes Limited | Wickford | 2010 |
| Community Money Advice South Wiltshire CIC | Salisbury | 2021 |
| Community Mortgage Services Ltd | Manchester | 2018 |
| Community Pharma Limited | London | 2025 |
| Community Publications Holdings Limited | Pocklington | 2021 |
| Community Reinsurance Corporation Limited | London | 1972 |
| Community Support Holdings Limited | Halifax | 2022 |
| Community Trust and Savings Limited | Wrexham | 2012 |
| Commuter Aircraft Leasing 2017 II Limited | London | 2017 |
| Comnivore Holdings Ltd | London | 2023 |
| Como Associates Holdings Limited | Bournemouth | 2025 |
| Como Capital Limited | Stockport | 2023 |
| Como Holdings (Europe) Limited | London | 2017 |
| Como Long Term Investments Limited | London | 2025 |
| Como Real Estate Limited | Belfast | 2017 |
| Comodius Capital Ltd | Milton Keynes | 2023 |
| Comoving Coordinates Ltd | London | 2018 |
| Comp Holdings Limited | Edgware | 2019 |
| Compacct Businesses Limited | Baldock | 1988 |
| Compact Financial Solutions Ltd | Bradford | 2012 |
| Compact Investments Ltd | Croydon | 2023 |
| Compagnie D'Assurance Maritime Ltd | London | 2024 |
| Compagnie DU Desert Holdings Ltd | London | 2021 |
| Compagnie DU Desert Limited | London | 2021 |
| Compagnie Generale D'Entreprises Ltd | London | 2023 |
| Companies Assistance Services Ltd | Hounslow / Greater London | 2014 |
| Companion Business Group Ltd | Crewe | 2026 |
| Companjon UK Limited | London | 2024 |
| Company 03051103HOLD Limited | Worcester | 2016 |
| Company 0426 Limited | Bath | 2026 |
| Company AE Ltd | London | 2012 |
| Company and Progress UK Ltd | London | 2025 |
| Company Asset Finance Limited | Newport | 2014 |
| Company Benefits Consultations Limited | Normanton | 2019 |
| Company Cards Group Limited | St Helens | 2024 |
| Company EYE Limited | London | 2008 |
| Company Finance House Limited | Bournemouth | 2018 |
| Company Finances Ltd | Cheltenham | 2008 |
| Company Funding Options Limited | Berwick-Upon-Tweed | 2014 |
| Company International Services Ltd | London | 2025 |
| Company PG Partners Limited | London | 2013 |
| Company Protection Limited | Derby | 2023 |
| Company Trading & Investments Ltd | London | 2016 |
| Companyplanet Ltd | Hounslow / Greater London | 2009 |
| Compare 365 Ltd | Preston | 2003 |
| Compare Car Finance Ltd | Bagshot | 2023 |
| Compare Drawdown Ltd | Harrogate | 2014 |
| Compare Geek Ltd | Slough | 2019 |
| Compare Home Insurance Limited | Derby | 2022 |
| Compare Insurance Ltd. | Swansea | 2009 |
| Compare Invoice Finance.Com Limited | Hyde | 2016 |
| Compare Life Insurance Ltd | Swansea | 2007 |
| Compare Mortgages Ltd | London | 2016 |