| Clarusto Ltd | Glasgow | A rating |
| Clas-SiC Wafer Fab Limited | Lochgelly | A rating |
| Clasado Limited | Reading | A rating |
| Clase Supermarket Ltd | Swansea | A rating |
| Class (UK) Limited | Chelmsford | A rating |
| Class 1 Personnel Limited | Hounslow | A rating |
| CLASS 1 WINDOWS AND DOORS LIMITED | FELTHAM | A rating |
| Class Delta Ltd | Runcorn | A rating |
| CLASS TECHNOLOGY SOLUTIONS LTD | Horsham | A rating |
| CLASS WORKWEAR LIMITED | LONDON | A rating |
| Class1 Dry Cleaners-Soletrader | Winchester | A rating |
| CLASSIC -TROPICAL FOODS LTD | Glasgow | A rating |
| CLASSIC BARBERS WALTON LTD | Walton on Thames | A rating |
| CLASSIC BEDS (UK) LTD | Dewsbury | A rating |
| Classic Care Homes (Devon) Limited | Teignmouth | A rating |
| Classic Care Limited T/A Bricklehampton Hall | Pershore | A rating |
| Classic Chippy Ltd | Prestonpans | A rating |
| CLASSIC CUISINE OF NORTHAMPTON LIMITED | Northampton | A rating |
| CLASSIC CUTZ LTD | Stockton On Tees | A rating |
| Classic Desserts Ltd. | Flusco | A rating |
| Classic Developments Gastropubs Ltd | Droitwich | A rating |
| Classic Dressage Collection Ltd | Ashorne, Warwick | A rating |
| Classic Fine Foods UK LImited | Park Royal | A rating |
| Classic Foods Ltd t/a Kismet | Falkirk | A rating |
| Classic Foods NCL Ltd T/A Cha Cha Chai | Newcastle upon Tyne | A rating |
| Classic Furniture Limited | Woking | A rating |
| Classic Global Services Limited | Pontypridd | A rating |
| Classic Halal Foods Limited | Ilford | A rating |
| Classic Health Care Solutions Ltd | Pontefract | A rating |
| CLASSIC HOUSE LTD | MILTON KEYNES | A rating |
| Classic India | Glasgow | A rating |
| CLASSIC LODGES LIMITED | Edinburgh | A rating |
| Classic Persian Restaurant (Bradford) Ltd | Bradford | A rating |
| Classic Quartz Stone Ltd | Reading | A rating |
| Classic ResourcesUK | Stockton-on-Tees | A rating |
| CLASSIC SEAFOOD LTD | London | A rating |
| Classic Sofas Ltd | Croydon | A rating |
| CLASSIC SPICES LTD T/A MEMORIES OF INDIA | Chichester | A rating |
| CLASSIC SUB LIMITED | London | A rating |
| Classical Events Ltd | London | A rating |
| Classical Numismatic Group LLC | London | A rating |
| Classik Catering | London | A rating |
| Classio Euro LTD T/A Sams Mobile Phones | Sheffield | A rating |
| Classique Co Trading LTD | Erith | A rating |
| Classroom365 Limited | London | A rating |
| Classtrend Ltd T/A Sheffield Speedway | Sheffield | A rating |
| Classy Cleaners | London | A rating |
| Classyhair Beauty Ltd | Nottingham | A rating |
| Clatterbridge Cancer Centre NHS Foundation Trust | Wirral | A rating |
| Claud Investments Ltd | Bromley | A rating |
| Claudia Dorsch Interior Design Limited | London | A rating |
| Claudia Sebire Limited | London | A rating |
| CLAUDIO CELIBERTI LTD T/A STUDIO CELIBERTI | STAINES-UPON-THAMES | A rating |
| Claudiu-Silviu Patrugan trading as Thorpe Hesley Dental Practice | Rotherham | A rating |
| Clavering Supermarket Limited | Saffron Walden | A rating |
| Claverley Medical Practice | Wolverhampton | A rating |
| Claxtons Home Improvements | Dereham | A rating |
| Clay Architecture Ltd | Gillingham | A rating |
| Clay Brook Healthcare Ltd | ENFIELD | A rating |
| Clay Cross Dental Practice | Clay Cross | A rating |
| Clay Labs UK Ltd | London | A rating |
| Clay Lane Medical Practice | Coventry | A rating |
| CLAY OVEN DAGENHAM LTD | Dagenham | A rating |
| CLAY OVEN SCUNTHORPE LIMITED | SCUNTHORPE | A rating |
| CLAY PIGEON ESSEX LIMITED | Chelmsford | A rating |
| Claylands Farmers | Glasgow | A rating |
| CLAYPOTTS (SC) LTD T/A TANDOORI KITCHEN | Dundee, Scotland | A rating |
| Claysmore AS Ltd | Exeter | A rating |
| Claystation Ltd | London | A rating |
| Claytex Services Limited | Leamington Spa | A rating |
| Clayton Health Centre - Drs Hanif & Bannuru Practice | Manchester | A rating |
| Clayton Medical Centre | Accrington | A rating |
| Clayton Precision Engineering Co.Ltd | Isleworth | A rating |
| Clayton VS Ltd | Coventry | A rating |
| Clayton West Cricket Club | Huddersfield | A rating |
| Claywood Construction Ltd | Leeds | A rating |
| CLC Contractors Ltd | Southampton | A rating |
| CLC International (UK) | Sandycroft | A rating |
| CLC Wholesale LImited | Glasgow | A rating |
| CLCA Company Ltd | Shrewsbury | A rating |
| CLCM AUTO SERVICES LTD | Edinburgh | A rating |
| CLdN Ports Killingholme Ltd | North Killingholme | A rating |
| CLdN Ro Ro Agencies Ltd | Purfleet-On-Thames | A rating |
| CLdN RoRo Ltd | London | A rating |
| CLEAN & FRESH SERVICES LTD | Lichfield | A rating |
| Clean Air Fund | London | A rating |
| Clean and Sparkle Limited | Maidenhead | A rating |
| Clean Digital Limited | Edinburgh | A rating |
| Clean Earth Energy Limited | Wadebridge | A rating |
| Clean Energy Transition LLP | London | A rating |
| Clean Energy Venture Management (UK) Ltd | London | A rating |
| Clean Food Group Limited | London | A rating |
| CLEAN GENIE LONDON EAST LTD | London | A rating |
| Clean Growth Investment Management | London | A rating |
| Clean Linen Services Limited | Camberley | A rating |
| Clean Power Hydrogen Group Limited | Doncaster | A rating |
| CLEAN WORLD BIRMINGHAM LTD | Birmingham | A rating |
| CLEAN YOUR SITE.COM LIMITED | London | A rating |
| Clean360 U.K Ltd | Derby | A rating |
| Cleanco Ventures Ltd | London | A rating |
| CleanEvent Services Limited | High Wycombe | A rating |
| Cleaning Equipment Sales and Services Limited | Stanmore | A rating |
| Cleaning Fairies Bristol Ltd | Bristol | A rating |
| CLEANING SERVICES NEAR ME LTD | Hemel Hempstead | A rating |
| CLEANING SOLUTIONS SUSSEX LIMITED | Lancing | A rating |
| Cleanny Property Services Ltd | London | A rating |
| CLEANSATION LIMITED | Romford | A rating |
| Cleanse a drive limited | Astwood Bank | A rating |
| Cleantech Engineering Limited | Edenbridge | A rating |
| Cleantech Group Europe Limited | London | A rating |
| Cleanux Chemicals Ltd | Acton | A rating |
| CLEANUX CHEMICALS LTD | WALTHAM ABBEY | A rating |
| Cleanwise Limited | Gravesend | A rating |
| Clear Amber Group Ltd | Milnathort | A rating |
| Clear AV Limited t/as OKTO Technologies | Lisburn | A rating |
| Clear Books Limited | London | A rating |
| Clear Corporation Training Limited | LONDON | A rating |
| Clear House Accountants | Stannmore | A rating |
| Clear Ideas Consultancy LLP | London | A rating |
| Clear Junction Limited | London | A rating |
| CLEAR LINE MAINTENANCE LTD | SHEFFIELD | A rating |
| Clear Pathway Care Ltd | Bournemouth | A rating |
| Clear Perspective Media (UK) Limited | London | A rating |
| Clear Score Technology Limited | London | A rating |
| Clear Sky Capital UK Limited | London | A rating |
| Clear Solutions UK | London | A rating |
| Clear Span Buildings Limited | Llandrinio | A rating |
| Clear Start Accountants | manchester | A rating |
| Clear Street Services UK Limited | London | A rating |
| Clear Thinking Care Limited | Plymouth | A rating |
| Clear Treasury (UK Trading) Limited | London | A rating |
| Clear View Imaging Ltd | Thame | A rating |
| Clear Visual Communications Ltd | Eccles | A rating |
| Clear Water Events Ltd | Halesowen | A rating |
| CLEARABEE LIMITED | Birmingham | A rating |
| Clearance Capital Limited | London | A rating |
| ClearBank Group Holdings Limited | London | A rating |
| CLEARBRIDGE HOUSING LIMITED | RUISLIP | A rating |
| Clearcare Solutions Limited | Stafford | A rating |
| CLEARCO INSURE LIMITED | DENTON | A rating |
| CLEARCOURSE PARTNERSHIP ACQUIRECO FINANCE LIMITED | London | A rating |
| CLEARCUT ACCOUNTING LIMITED | Manchester | A rating |
| Clearcut Physiotherapy Ltd | London | A rating |
| Cleared Europe services | Ashford | A rating |
| Clearer.io UK Ltd | Leicester | A rating |
| Clearglass Analytics Limited | London | A rating |
| Clearlake Capital (UK) LLP | London | A rating |
| Clearlake Capital Group Limited | London | A rating |
| Clearlift Material Handling Ltd | Portadown | A rating |
| Clearlight Saunas UK Limited | London | A rating |
| Clearly Drinks Limited | Sunderland | A rating |
| Clearly Technologies Limited | London | A rating |
| Clearmacro Limited | London | A rating |
| Clearmatics Technologies Ltd | London | A rating |
| ClearMotion UK Limited | NUNEATON | A rating |
| Clearpay Finance Ltd | London | A rating |
| ClearPoint Neuro UK Ltd | Guildford | A rating |
| Clearroute UK Limited | London | A rating |
| Clearsense Ventures Limited | London | A rating |
| CLEARSKIN SKIN CARE LIMITED | Luton | A rating |
| ClearSpace Today Ltd | London | A rating |
| CLEARSPRING LIMITED | London | A rating |
| Clearstream London Limited | London | A rating |
| Clearsulting Ltd | London | A rating |
| Cleartax Solutions Ltd. | Birmingham | A rating |
| Cleartwo Limited | Cheshire | A rating |
| Clearview Accountants Limited | Kidderminster | A rating |
| CLEARVIEW DRIVING LTD | SLOUGH | A rating |
| Clearview Healthcare Partners (UK) Limited | London | A rating |
| ClearView Research | London | A rating |
| Clearvue Investments Limited | Helensburgh | A rating |
| ClearVUE.Business Limited | Gateshead | A rating |
| Clearwater Analytics, Ltd. | Edinburgh | A rating |
| Clearwater Care (Leadon Court) Limited | Cwmbran | A rating |
| Clearwater Corporate Finance LLP | Birmingham | A rating |
| ClearWater Dental LTD | Jedburgh | A rating |
| Clearwater Dynamics Ltd | Poole | A rating |
| Clearwater Fine Foods (Europe) Limited | Windsor | A rating |
| Clearwater Sensors Ltd | Southampton | A rating |
| Clearwater Services | Teignmouth | A rating |
| Clearwater Wealth Management | London | A rating |
| Clearwell Capital Limited | London | A rating |
| Clearwell Energy Holdings Limited | Aberdeen | A rating |
| Clearwood International Ltd | Cambridge | A rating |
| Cleary Gottlieb Steen & Hamilton LLP | London | A rating |
| Cleator Cricket Club | Cleator | A rating |
| Cleaver Property Management Limited | Berkshire | A rating |
| Clece Care Services Ltd | London | A rating |
| Cleckheaton Cricket Club | Cleckheaton | A rating |
| Cledara Limited | London | A rating |
| Clee Medical Centre | Cleethorpes | A rating |
| Cleen Finish Ltd | London | A rating |
| Cleethorpes Cricket Club | Cleethorpes | A rating |
| Cleethorpes Dental Practice Limited | Cleethorpes | A rating |
| Cleeve Cricket Club | Bristol | A rating |
| Cleeve House Care Ltd T/A Cleeve House | Malvern | A rating |
| Cleeve Lodge Limited | Goring on Thames | A rating |
| Cleeve Park School | Sidcup | A rating |
| Clegg Construction Limited | Nottingham | A rating |
| CLEGGS LANE PRACTICE LIMITED | Manchester | A rating |