| Carrick Music Agency | Comrie | A rating |
| Carrickfergus Cricket Club | Carrickfergus | A rating |
| Carrickfergus Gateway Trust | Carrickfergus | A rating |
| CARRICKMORE HEALTH CENTRE | CARRICKMORE | A rating |
| Carrier Solutions UK Ltd | London | A rating |
| Carrington House Ltd | Hatfield | A rating |
| Carrington Hull Associates Limited | London | A rating |
| Carrington Pharmacy | Nottingham | A rating |
| Carritech | Lewes | A rating |
| Carrold Hill Ltd T/As P & C Residential Services Ltd | Workington | A rating |
| Carroll & Meynell Transformers Limited | Stockton-On-Tees | A rating |
| CARROM LTD | Weymouth | A rating |
| Carron Contracts Ltd | Glasgow | A rating |
| CARRY FRESH LTD | Liverpool | A rating |
| Carryduff Building Supplies Limited | Belfast | A rating |
| CARS 4 U TRADERS LTD | Manchester | A rating |
| CARS CLUB TRADERS LIMITED | Langley | A rating |
| CARS EMPORIUM LIMITED | Manchester | A rating |
| CARS HOTSPOT LIMITED | Ringwood, Hampshire | A rating |
| Cars Hub UK Ltd | Sanady | A rating |
| CARS HUNT LTD | London | A rating |
| CARS IN MK LTD | Milton Keynes | A rating |
| CARS SPOT LIMITED | Ilford | A rating |
| Cars Yard Limited | London | A rating |
| Cars4you Ltd | Edinburgh | A rating |
| Carshalton Boys Sports College | Carshalton | A rating |
| CARSHALTON LTD | Surrey | A rating |
| Carslink Ltd | LUTON | A rating |
| Carsten Astheimer Limited | Warwick | A rating |
| Carta Financial Services Limited | London | A rating |
| CARTCORNER LIMITED | Devon | A rating |
| Cartech Mot Ltd | Enfield | A rating |
| CARTELL UK LIMITED | CORBY | A rating |
| Carter Bond Limited | Harrow | A rating |
| Carter Bookman & Co Limited | London | A rating |
| Carter Brown - The Expert Service Limited | Birmingham | A rating |
| Carter Chatila Ltd | London | A rating |
| CARTER CHEMIST (2005) LIMITED | Northwood | A rating |
| Carter Chemist Limited | Rickmansworth | A rating |
| Carter Fitch Limited | Poole | A rating |
| Carter Gregson Gray | London | A rating |
| Carter Grill Ltd | Coventry | A rating |
| Carter Jonas Service Company | Peterborough | A rating |
| Carter Manufacturing Limited | Abingdon | A rating |
| CARTER TECH LTD | NEWQUAY | A rating |
| Carter Thermal Industries | Birmingham | A rating |
| Carter-Ruck | London | A rating |
| Cartercom Ltd | Middlesbrough | A rating |
| Carterhatch Homes LTD | London | A rating |
| Carters Green Clinic & Business Centre Ltd | West Bromwich | A rating |
| CARTERS GREEN HEALTHCARE SERVICES LIMITED | WEST BROMWICH | A rating |
| CARTERS MALVERN LTD | Birmingham | A rating |
| Carterwood Ltd | Bristol | A rating |
| Cartesian Limited | London | A rating |
| Cartgator Limited | Aylesbury | A rating |
| Cartledge Agri Ltd T/A Manor Farm Dairy | Shepton Mallet | A rating |
| CARTODB UK Limited | London | A rating |
| CARTOOS GRILL LTD | ABERDEEN | A rating |
| Cartopia Ltd | Mill Hill | A rating |
| Cartor Security Printers Ltd | WOLVERHAMPTON | A rating |
| CARTREE LIMITED | London | A rating |
| Cartref Annwyl (Ammanford) Ltd | Ammanford | A rating |
| Cartref Homes UK Ltd. | Sittingbourne | A rating |
| Cartref Ni Limited | St Asaph | A rating |
| Cartrefi Cymru Cooperative | Cardiff | A rating |
| Cartridge Atelier Ltd | Uxbridge | A rating |
| CARTUS LIMITED | Swindon | A rating |
| cartvalecare LLP | Cathcart | A rating |
| Cartwright King Solicitors Ltd | Blackburn | A rating |
| Cartwright Pickard Architects | London | A rating |
| Cartwright-Hignett Partners | BRADFORD-ON-AVON | A rating |
| CARTWRIGHTS CHEMISTS LIMITED | Manchester | A rating |
| Carus Animal Health Limited | Reigate | A rating |
| Caruso St John Architects LLP | London | A rating |
| CarVal Investors UK Limited | London | A rating |
| CARVALHO INDEPENDENT LIVING L LIMITED | Dudley | A rating |
| Carvansons Ltd | Haslingden | A rating |
| Carve Interiors Limited | Stoke on Trent | A rating |
| Carvender Ltd | Epping | A rating |
| CARVER (WOLVERHAMPTON) LTD | Wolverhampton | A rating |
| Carver Group Ltd | Walsall | A rating |
| Carviews Ltd | Birmingham | A rating |
| Carwood Smith Limited | London | A rating |
| Carworld (Cambs) Ltd | Peterborough | A rating |
| carwow Ltd. | London | A rating |
| Carz City Ltd | Bristol | A rating |
| CARZ EXPRESS LIMITED | Ilford | A rating |
| CARZ4LESS LTD | London | A rating |
| CAS Care Solutions Ltd. | New Milton | A rating |
| CAS CROSSWAYS LIMITED | CLACTON-ON-SEA | A rating |
| CAS JACKSON ROAD LIMITED | 2 JACKSON ROAD | A rating |
| CAS Ltd | Edinburgh | A rating |
| CAS ST JOHNS ROAD LIMITED | CLACTON-ON-SEA | A rating |
| Casa AmaCord Ltd | London | A rating |
| CASA BAMBOO LTD T/a Pho Le Vietnamese Restaurant | Leicester | A rating |
| Casa Bella Developments Ltd | London | A rating |
| Casa caffe Limited | Mitcham | A rating |
| CASA Care Limited | Leamington Spa | A rating |
| Casa Cruz London Limited | London | A rating |
| Casa De Goa Limited | Hounslow | A rating |
| Casa de Oracion UK | London | A rating |
| Casa Design Group Limited | Welling | A rating |
| Casa Environmental Services Ltd | Willsbridge | A rating |
| CASA FRUTAS LTD | LONDON | A rating |
| Casa Jorba Limited | London | A rating |
| CASA NOTTINGHAM LTD | Nottingham | A rating |
| Casa Parmigiana | Bracknell | A rating |
| Casa Pizza Ltd | Port Talbot | A rating |
| CASA ROSA PIZZA LTD T/A Casa Rosa | Birtley | A rating |
| CASA TERRA LTD | BUCKINGHAMSHIRE | A rating |
| Casablanca | Loughton | A rating |
| CASABLANCA CAFE LIMITED | LONDON | A rating |
| Casacucina Trading Ltd | Potters Bar | A rating |
| CASAEGIS LIMITED | Oadby | A rating |
| Casalee Ltd | Alton | A rating |
| CASALUBE UK LIMITED | Kings Langley | A rating |
| casamera trading ltd | birmingham | A rating |
| CasaPay Ltd | London | A rating |
| Casarotto Ramsay and Associates LTD | London | A rating |
| Casbah Food and Wine | Crawley | A rating |
| Casbah Group Limited | London | A rating |
| Casbens Supported Living Community And Home Support Services Ltd | Swindon | A rating |
| Cascade (Banks House) Limited | Norwich | A rating |
| Cascade (Charlton House) Limited | Norwich | A rating |
| Cascade (Cohen House) Limited | Norwich | A rating |
| Cascade (Stiles House) Limited | Withernsea | A rating |
| Cascade Aerospace Engineering Ltd | Camberley | A rating |
| Cascade Communications Limited | London | A rating |
| Cascade Parent Limited | London | A rating |
| Casco Food & Wine Ltd | Slough | A rating |
| Cascoda Limited | Southampton | A rating |
| CASE COLLECTION LTD | HOUNSLOW | A rating |
| Case Elegance Limited | Bolton | A rating |
| Case Furniture Ltd | London | A rating |
| CASE INTERNATIONAL EDUCATION LTD | London | A rating |
| Case International, LLC | London | A rating |
| Case45 Ltd | London | A rating |
| Caseena Limited | London | A rating |
| Casella Family Brands (Europe) Limited | Duxford | A rating |
| CASEN DOORS LTD | WINDSOR | A rating |
| Casey Consultants LTD | Dungannon | A rating |
| Casey's Salmon Ltd | Strabane | A rating |
| CASGO CONNECTIONS LIMITED | HOVE | A rating |
| CASH & CARRY BEDS LTD | London | A rating |
| Cashcounts Ltd | North Harrow | A rating |
| Cashdash UK Limited | London | A rating |
| Cashel Travel Limited | Edinburgh | A rating |
| CashFlows Europe Ltd | London | A rating |
| CASHLONG GROUP LIMITED | LONDON | A rating |
| Cashmaster International Ltd | Dalgety Bay | A rating |
| CASHMERE PALETTE LTD | SOLIHULL | A rating |
| CASHMERE SYSTEMS LTD | Manchester | A rating |
| Cashorina Limited | Harrow | A rating |
| Casio Electronics Co Limited | Wembley | A rating |
| Cask and Curry Limited T/a Hen and Chickens | Birmingham | A rating |
| Cask Industries Ltd | London | A rating |
| Cask Trade Limited | London | A rating |
| Caskgate Street Surgery | Gainsborough | A rating |
| CASM Technology LLP | London | A rating |
| Casper Kitchen Ltd T/A Epic Burgers | London | A rating |
| Casper Mueller Kneer Ltd | London | A rating |
| CASPER STORES LTD | WOLVERHAMPTON | A rating |
| CASPERAKI MULTIMEDIA SOLUTIONS LTD. | London | A rating |
| Caspertron Ltd | Manchester | A rating |
| CASPIAN COOLING LTD | Wigan | A rating |
| Caspian Healthcare Ltd | London | A rating |
| Caspian Pizza Plus Ltd | Heywood | A rating |
| Caspian Pizza St Johns | Worcester | A rating |
| CASPIAN SCHOOL OF ACADEMICS LTD | London | A rating |
| Caspian Supply Limited | London | A rating |
| CASPIAN WALSALL LIMITED T/A CASPIAN PIZZA | Walsall | A rating |
| Caspro Management Ltd | London | A rating |
| CASS CONSTRUCTION SERVICES LTD | London | A rating |
| Cass Hayward LLP | Chepstow | A rating |
| CASS INTERNATIONAL EDUCATION & CONSULTING LTD | London | A rating |
| Casse Croute | London | A rating |
| Cassidy and Ashton Group Ltd | Preston | A rating |
| Cassini Systems Limited | London | A rating |
| Cassiobury Court | Watford | A rating |
| Cassiobury Dental practice | Watford | A rating |
| Casson Mann | London | A rating |
| Cassyni Limited | London | A rating |
| Cast Advanced Concretes Ltd | Christchurch | A rating |
| Cast Connex UK Limited | London | A rating |
| Cast Group Services Ltd | London | A rating |
| Cast Iron Games Limited | Wakefield | A rating |
| CAST ME IF YOU CAN LTD | London | A rating |
| CAST ME LTD | London | A rating |
| Cast Software Limited | London | A rating |
| Cast Strategy Limited | London | A rating |
| Castel Froma Neuro Care Ltd | Royal Leamington Spa | A rating |
| Castell Safety International Ltd | London | A rating |
| Castell Ventures Limited | Ewloe | A rating |
| Castella Fish and Chips LTD | London | A rating |
| Castellum Catering Limited | Dover | A rating |
| Castelnau Group Services Limited | London | A rating |
| Castelo Notaries Limited | London | A rating |
| Casterbridge Tours Limited | London | A rating |
| Casterton Leisure Ltd | Ambleside | A rating |
| Castle Cuisine Ltd | Nottinghamshire | A rating |