| Corporate Travel Management (United Kingdom) Limited | London | A rating |
| Correlation Risk Partners Limited | London | A rating |
| CORSAIR CAPITAL LLP | LONDON | A rating |
| Corsair Components Limited (UK) | Berkshire | A rating |
| Corsearch UK Limited | London | A rating |
| Corteva Agriscience UK Limited | Cambridge | A rating |
| Cortland Development UK Limited | London | A rating |
| Corvia Limited t/a Ticketer | Hungerford | A rating |
| Cosco Shipping (UK) Co Ltd | Barking | A rating |
| Cosentino UK Limited | Hook | A rating |
| COSL Offshore Crew AS | Aberdeen | A rating |
| Costain Limited | London | A rating |
| CoStar UK Limited | London | A rating |
| Coster Group UK | Derby | A rating |
| Costero Holdings Limited | London | A rating |
| Cotton On UK (Pty) Ltd. | London | A rating |
| COTY Services UK Limited | Ashford | A rating |
| Couchbase Limited | London | A rating |
| Council of Local Authorities for International Relations, London | London | A rating |
| Coupa Software UK Ltd | London | A rating |
| Course5 Intelligence Limited | London | A rating |
| Coursera UK Limited | London | A rating |
| Covasant Technologies (UK) Private Limited | London | A rating |
| Cover Genius Ltd | London | A rating |
| Cover-More Insurance Services Ltd | Uxbridge | A rating |
| Coveris Flexibles Holdings UK Limited | Pinchbeck | A rating |
| Coverys Services Limited | London | A rating |
| Covington & Burling LLP | London | A rating |
| Cowbell Cyber Ltd | London | A rating |
| Cowen International Limited | London | A rating |
| COWI UK Ltd | London | A rating |
| Cox Hinkins & Co Limited | Oxford | A rating |
| Coxbury Limited | London | A rating |
| Cozentus Technologies UK Limited | Harrow | A rating |
| CP Foods UK Ltd | Malvern | A rating |
| CPCS Transcom UK Ltd | London | A rating |
| Cpl Talent Solutions Limited | Reading | A rating |
| CPPP UK LIMITED | LONDON | A rating |
| CQS (UK) LLP | London | A rating |
| CR Construction (U.K.) Company Limited | London | A rating |
| CRA International (UK) Limited | London | A rating |
| Cracknell Limited | London | A rating |
| CRAEMER UK LIMITED | Telford | A rating |
| Craig &Rose Ltd | London | A rating |
| Craig International Limited | Aberdeen | A rating |
| Crain Communications Limited | London | A rating |
| Cramlington Precision Forge Limited | Cramlington | A rating |
| Crane Limited | Ipswich | A rating |
| Crane Merchandising Systems Limited | Chippenham | A rating |
| Cranemere International Limited | London | A rating |
| Cravath, Swaine & Moore LLP | London | A rating |
| Crawford & Company Adjusters (UK) Ltd | London | A rating |
| Crayon | Maidenhead | A rating |
| Crayside Consulting Ltd | Basingstoke | A rating |
| CRC Evans Limited | Kintore | A rating |
| Creandum Advisor LLP | London | A rating |
| CREATE ADVERTISING LIMITED | London | A rating |
| Creatio Britain Ltd | London | A rating |
| Creation Consumer Finance Limited | Solihull | A rating |
| Creation Financial Services Limited | Solihull | A rating |
| Creative Artists Agency UK Ltd | London | A rating |
| Creative Content Works | Manchester | A rating |
| Creative Foods Europe Limited | Burton-on-Trent | A rating |
| Creative Goods Merchandising Ltd | London | A rating |
| Creative Restaurant Group Ltd | London | A rating |
| Creative Synergies Consulting Limited | Warwick | A rating |
| CreativeDrive EMEA Ltd | London | A rating |
| CreatorIQ International Limited | London | A rating |
| Credendo - Trade Credit Insurance | London | A rating |
| Credico Marketing Limited | Chester | A rating |
| Credit Agricole Corporate & Investment Bank London Branch | London | A rating |
| Credit Agricole S.A. London Branch | London | A rating |
| Credit Data Research Ltd | London | A rating |
| CREDIT INDUSTRIEL ET COMMERCIAL | London | A rating |
| Credit Karma UK Ltd | London | A rating |
| Crescent Credit Europe LLP | London | A rating |
| Crestline Europe, LLP | London | A rating |
| CRH Group Limited | London | A rating |
| CRIF REALTIME LIMITED | London | A rating |
| Crimson Education (Europe) Limited | London | A rating |
| Crimson Tangerine Ltd | London | A rating |
| CRISIL IREVNA UK LIMITED | London | A rating |
| Criteo Ltd | London | A rating |
| Critical Software Ltd | Southampton | A rating |
| Croatia National Tourist Board | London | A rating |
| Croda International Plc | Goole | A rating |
| Cron AI Ltd | London | A rating |
| Crop Demetra Limited | Northumberland | A rating |
| CROP PHARM LTD | London | A rating |
| Cross Media Limited | London | A rating |
| CrossBoundary UK Limited | London | A rating |
| Crossfuze Limited | London | A rating |
| Crossover Markets UK Limited | London | A rating |
| CrowdStrike UK Limited | London | A rating |
| CROWE U.K. LLP | London | A rating |
| Crowell & Moring U.K. LLP | London | A rating |
| Crown Lift Trucks Ltd | Basingstoke | A rating |
| Crown Packaging Manufacturing UK Ltd | Wantage | A rating |
| Crown Pet Foods Limited | Castle Cary | A rating |
| Crown Worldwide Limited | South Ruislip | A rating |
| CRU International Ltd | London | A rating |
| Cryptio Ltd | London | A rating |
| Crypto Facilities Ltd | London | A rating |
| CS Disco Ltd | London | A rating |
| CSA Group Testing UK Ltd | Deeside | A rating |
| CSAM Optima UK Limited | Reading | A rating |
| CSC Administrative Services Limited | London | A rating |
| CSC Computer Sciences Limited | Farnborough | A rating |
| CSC MANAGEMENT SERVICES (UK) LIMITED | LONDON | A rating |
| CSSCK UK Ltd | London | A rating |
| CT Group (UK) Trading Limited | London | A rating |
| CTC LONDON LIMITED | London | A rating |
| CTG Metropark Limited | Richmond | A rating |
| CTS Offshore and Marine Limited | Hammersmith | A rating |
| CUATRECASAS, LLP | London | A rating |
| Cube Content Governance Ltd. | London | A rating |
| CubeLogic Limited | London | A rating |
| Cubic Transportation Systems Limited | Redhill | A rating |
| Cubico Sustainable Investments Limited | London | A rating |
| Culpitt Ltd | Ashington | A rating |
| Cultivist Limited | London | A rating |
| Cultura Technologies Limited | Chorley | A rating |
| Culture Amp Limited | London | A rating |
| Cummins Ltd | Darlington | A rating |
| Cundall Johnston & Partners LLP | Newcastle upon Tyne | A rating |
| Currencies Direct Limited | London | A rating |
| Current Health Limited | Edinburgh | A rating |
| Currie & Brown International Limited | London | A rating |
| Currys Group Limited | London | A rating |
| Curtis,Mallet-Prevost, Colt & Mosle LLP | London | A rating |
| Curve UK Limited | London | A rating |
| Cushman & Wakefield Debenham Tie Leung Limited | London | A rating |
| Cutfield Freeman & Company Limited | London | A rating |
| Cutting Edge Music (Holdings) Ltd | LONDON | A rating |
| CVA Corporate Value Associates UK Limited | London | A rating |
| CVC Advisers Limited | London | A rating |
| Cvent Europe Limited | London | A rating |
| CVP Global Services Ltd | London | A rating |
| CWA International Ltd | London | A rating |
| CWT UK Group Ltd | Potters Bar | A rating |
| CXC GLOBAL EMEA UK LIMITED | Kings Langley | A rating |
| CXG UK Ltd | London | A rating |
| CY Shipping UK ltd | London | A rating |
| CyanConnode Limited | Cambridge | A rating |
| CYBAGE SOFTWARE UK LIMITED | London | A rating |
| CybelAngel UK Limited | Marylebone | A rating |
| CyberCube Analytics Europe Limited | London | A rating |
| Cyclife UK Limited | Workington | A rating |
| Cyera UK Ltd | London | A rating |
| CYGAMES EUROPE LIMITED | London | A rating |
| Cygilant UK Limited | Belfast | A rating |
| Cygnet Infotech Limited | London | A rating |
| Cyient Europe Limited | Reading | A rating |
| Cykube Ltd | London | A rating |
| Cylindo Limited | Egham | A rating |
| Cynomi Ltd | London | A rating |
| Cynopsis Solutions UK Limited | London | A rating |
| Cynosure UK Ltd | Cookham | A rating |
| CYP UK Limited | Shepperton | A rating |
| Cypress Book Company UK Limited | London | A rating |
| Cyrus Capital Partners Europe LLP | LONDON | A rating |
| Cytec Engineered Materials Ltd | Wrexham | A rating |
| Cytel Statistical Services and Software UK Limited | London | A rating |
| CYTS (UK) Tours Ltd | London | A rating |
| CZARNIKOW GROUP LIMITED | London | A rating |
| CZICC UK LIMITED | London | A rating |
| d-fine Ltd | London | A rating |
| D-Link (Europe) Limited | Harrow | A rating |
| D. E. Shaw & Co. (U.K.), Ltd. | London | A rating |
| d&b audiotechnik GB Limited | Stroud | A rating |
| D2 Legal Technology Ltd | London | A rating |
| D2L Europe Limited | London | A rating |
| daappa Limited | London | A rating |
| DABUR INTERNATIONAL LIMITED | LONDON | A rating |
| DAC Beachcroft LLP | London | A rating |
| Dachser Ltd | Northampton | A rating |
| DACSA Limited | Liverpool | A rating |
| DAF Trucks Limited | Bucks | A rating |
| Dage Precision Industries Limited | Aylesbury | A rating |
| DAHER AEROSPACE LTD | Derby | A rating |
| Dahua Technology UK Limited | Maidenhead | A rating |
| DAI Global UK | London | A rating |
| DAI-ICHI LIFE INTERNATIONAL (EUROPE) LIMITED | London | A rating |
| Daido Industrial Bearings Europe Limited | Somerset | A rating |
| Daido Metal Co., Ltd. European Technical Centre (UK) | Ilminster | A rating |
| DAIFUKU AIRPORT UK LTD. | Kingston Upon Hull | A rating |
| Daihatsu Infinearth (Europe) Ltd. | London | A rating |
| Daiichi Sankyo UK Limited | Uxbridge | A rating |
| Daikin Airconditioning UK Limited | Weybridge | A rating |
| Daikin Applied (UK) Limited | Cramlington | A rating |
| DailyPay (NI) LTD | Belfast | A rating |
| Daimler Truck UK Limited | Milton Keynes | A rating |
| Dairy Crest Limited (trading as Saputo Dairy UK) | Weybridge | A rating |
| Daiwa Asset Management (Europe) Ltd | London | A rating |
| Daiwa Capital Markets Europe Limited | London | A rating |
| Daiwa Corporate Advisory Ltd | London | A rating |
| DAIWA HOUSE UK LIMITED | London | A rating |
| Daiwa Sports Ltd | Wishaw | A rating |
| DAKS Simpson Limited | London | A rating |
| Dalata Cardiff Limited | Cardiff | A rating |