| Castle Air Limited | Liskeard | A rating |
| Castle Care Scotland Ltd | Inverness | A rating |
| Castle Cars Dudley Ltd | Dudley | A rating |
| castle central limited | Wes Bromwich | A rating |
| Castle Consulting Group Limited | Bromley | A rating |
| Castle Convenience | Northwich | A rating |
| Castle convenience ltd | Bournemouth | A rating |
| Castle Convenience Store Limited | Cumnock | A rating |
| Castle Convenience Stores | Birmingham | A rating |
| Castle Craig Hospital | West Linton | A rating |
| CASTLE CREW LTD | Biggleswade | A rating |
| Castle Dawson Limited | York | A rating |
| Castle Dene Surgery Limited | durham | A rating |
| Castle Dental Practice Ltd | Barnard Castle | A rating |
| Castle Donington Surgery | Derby | A rating |
| Castle Douglas Medical Group | Castle Douglas | A rating |
| Castle Eden Cricket and Recreational Club | Hartlepool | A rating |
| Castle Enterprise 2017 Ltd | Belfast | A rating |
| CASTLE FOOD DISTRIBUTION LTD | Witham | A rating |
| CASTLE FOODS STORE LTD | Edinburgh | A rating |
| Castle Gates Store | Shrewsbury | A rating |
| Castle Grove Nursing Home | Tiverton | A rating |
| Castle Grove Retirement Home Partnership | Tiverton | A rating |
| Castle Harbour Investments Limited | London | A rating |
| Castle Hayes Pursey LLP | London | A rating |
| Castle Healthcare Practice | Nottingham | A rating |
| Castle Hill House Ltd | Bodmin | A rating |
| CASTLE HOLDINGS U.K. LTD. | Coventry | A rating |
| Castle Hotel Windermere Ltd | Pitlochry | A rating |
| Castle House Nursing Home Limited | Somerton | A rating |
| Castle Inventories | London | A rating |
| Castle Island UK | London | A rating |
| Castle Kitchen | Caerphilly | A rating |
| Castle Partnership | Norwich | A rating |
| Castle Point Borough Council | Benfleet | A rating |
| Castle School Education Trust | Mangotsfield | A rating |
| Castle Ship Technical Management Ltd | Chichester | A rating |
| Castle Street Dental | Forfar | A rating |
| Castle Trading Ltd | London | A rating |
| Castle Trust Capital Plc | London | A rating |
| Castle Villas Limited | Halifax | A rating |
| Castle Water Limited | Blairgowrie | A rating |
| Castlebank Care Home | County Durham | A rating |
| Castlebridge Hotels Birmingham Airport Employment Limited | Leamington | A rating |
| Castlebridge Hotels Chester Opco Ltd | Leamington | A rating |
| Castlebridge Hotels Winchester Opco Limited | Leamington | A rating |
| Castlechain Ltd t/a Bleeding Heart | London | A rating |
| Castlecrafts Ltd | Driffield | A rating |
| Castlecroft Road Limited | Wolverhampton | A rating |
| Castlefield Advisory Partners Limited | Manchester | A rating |
| CASTLEFIELD CAR CENTRE LTD | Heywood | A rating |
| Castlefield Gallery | Manchester | A rating |
| Castlefield Hospitality Ltd | Manchester | A rating |
| Castlefield Stores | Leominister | A rating |
| Castlefields Health Centre | Runcorn | A rating |
| Castlefields Surgery | Stafford | A rating |
| Castleford Cricket Club | Castleford | A rating |
| CASTLEFORD TIGERS RLFC LTD | CASTLEFORD | A rating |
| Castleforge Partners Limited | London | A rating |
| CASTLEGATE (NANTGARW) LTD | CAERPHILLY | A rating |
| Castlegate and Derwent Surgery | Cockermouth | A rating |
| Castlegate Investments (Edinburgh) Limited | Edinburgh | A rating |
| CASTLEGATE RETAIL LTD | Banff | A rating |
| Castlehomes Estate Agents Ltd | Preston | A rating |
| Castlelake (UK) LLP | London | A rating |
| Castlemeadow Care Home ( Halesworth) Ltd | Halesworth | A rating |
| CASTLEMERE COMMUNITY CENTRE | ROCHDALE | A rating |
| CASTLEPAVING IRELAND LTD | Omagh | A rating |
| Castlepoint Systems Limited | Orpington | A rating |
| Castlereagh Motors Limited | Newtownbreda | A rating |
| CASTLES SECURITY AND FM LIMITED | Berkshire | A rating |
| CASTLET LIMITED | LINCOLN | A rating |
| Castleton Commodities UK Limited | London | A rating |
| Castleton Fruit Limited | Fordoun | A rating |
| Castleton Health Centre | Rochdale | A rating |
| Castletown Law Limited | Londniddry | A rating |
| CASTLETROY RESIDENTIAL HOME | LUTON | A rating |
| Castleview Tynemouth Ltd T/A IZTUZU | Tynemouth | A rating |
| Castlewood Hotels Holding Ltd | Folkestone | A rating |
| Castons Consulting Limited | London | A rating |
| Casual Films Limited | London | A rating |
| Casual Fitters Ltd | London | A rating |
| Caswell Chiropractic Limited | London | A rating |
| Casyan Ltd T/as Cleeve House | Worcester | A rating |
| CAT G1 LIMITED T/A BEST ONE PREMIER STORE | KILMARNOCK | A rating |
| Cat Tech Europe Limited | Scunthorpe | A rating |
| CAT UK SERVICES LIMITED | Avonmouth | A rating |
| Catalan Tourist Board UK and Ireland Limited | London | A rating |
| Catalent Micron Technologies Limited | Dartford | A rating |
| Catalent Nottingham Limited | Nottingham | A rating |
| Catalent UK Swindon Zydis LTD | Swindon | A rating |
| Catalina and Partners Ltd | London | A rating |
| Catalina Marketing UK | Notting Hill | A rating |
| Catalina Services UK Limited | Worthing | A rating |
| Catalonia Trade & Investment London Limited | London | A rating |
| CATALYSE RESEARCH LTD | LONDON | A rating |
| Catalysis Communications Ltd | Camberley | A rating |
| Catalyst Capital | London | A rating |
| Catalyst Corporation Ltd | Brighton | A rating |
| Catalyst Event Production Services Limited | Dalgety Bay | A rating |
| Catalyst IT Europe Limited | Brighton | A rating |
| Catalyst Marketing Services Ltd | London | A rating |
| Catalyst Performance Ltd | London | A rating |
| Catalyst Sport and Health Limited | London | A rating |
| Catalystnex Limited | Leeds | A rating |
| Catalyx Marketing Limited | Canterbury | A rating |
| Catamaran Food Limited T/A Tandooriwala | Forfar | A rating |
| Catamountain Limited T/A Kebab Centre | Middlesborough | A rating |
| Catania Pizza Ltd | London | A rating |
| Catapult Enterprises Ltd | Nuneaton | A rating |
| Catapult Labs Ltd | London | A rating |
| Catapult Sports Limited | Leeds | A rating |
| Catavia Aerospace Limited | Ashford | A rating |
| Catch 22 Charity Limited | London | A rating |
| Catch Digital | London | A rating |
| CATCH22 SM LTD | LONDON | A rating |
| CATCHGATE STORES LIMITED T/A Catchgate Food Store | Stanley | A rating |
| Catcy Care Limited | London, Greater London | A rating |
| Cater london Ltd | London | A rating |
| Cater-Clean Solutions Limited | Harrogate | A rating |
| CATER-SEN LTD | London | A rating |
| Caterbox | Winchester | A rating |
| Caterdesk Limited | London | A rating |
| Caterham Cars Ltd | Darftord | A rating |
| Caterham Dental Centre | Caterham | A rating |
| Caterham Mini Market Limited | Surrey | A rating |
| Caterham School Ltd | Caterham | A rating |
| Caterham Surgical Supplies Limited | Milton Keynes | A rating |
| CATERING & CLEANING SOLUTIONS LTD | London | A rating |
| Catering 786 Ltd | Slough | A rating |
| Catering Energy Ltd. | Sale | A rating |
| Catering UK Ltd | London | A rating |
| CATERLAND HOSPITALITY LTD TRADING AS CHOURANGI | LONDON | A rating |
| CATERMARKE LTD | BIRMINGHAM | A rating |
| Catermatch Solutions Ltd | MANCHESTER | A rating |
| Caterpaper Ltd | Ipswich | A rating |
| Caterpillar UK Holdings Limited | Leicester | A rating |
| Caterpillars Preschool (Sussex) Limited | East Grinstead | A rating |
| Catfield Stores & Post Office | Great Yarmouth | A rating |
| Catford Brothers Ltd | London | A rating |
| Catford Express | London | A rating |
| Catford Supermarket ltd T/As Catford Supermarket | Catford | A rating |
| Cathay Pacific Airways Ltd | Hammersmith | A rating |
| CATHAY PACIFIC MANAGEMENT LTD | Birmingham | A rating |
| CATHAY PETROLEUM INTERNATIONAL UK LTD | LONDON | A rating |
| Cathedral Care Services Ltd | Sale | A rating |
| Cathedral Church of St Andrews in Wells | Wells | A rating |
| Cathedral Medical Group | Chichester | A rating |
| Cathedral Schools Trust | North Somerset | A rating |
| CATHEDRAL SQUARE LTD T/A SUBWAY | PETERBOROUGH | A rating |
| Cathelco Limited | Chesterfield | A rating |
| Cathena Healthcare Limited | Chigwell | A rating |
| CATHERINE BEST UK LIMITED | London | A rating |
| Catherine Homecare Ltd | Hounslow | A rating |
| Catherine House Limited | Frome | A rating |
| Catherine Isted | Horley | A rating |
| Catherine Lamacraft | Dunster, Minehead | A rating |
| CATHIE ASSOCIATES LIMITED | Newcastle Upon Tyne | A rating |
| Cathodic Protection and Corrosion Control Company Ltd | Crewe | A rating |
| Cathodic Protection Co. Ltd. | Grantham | A rating |
| Catholic Care | Leeds | A rating |
| Catholic Children's Society | London | A rating |
| Catholic Diocese of Derry | Londonderry | A rating |
| Catholic Diocese of Portsmouth | Portsmouth | A rating |
| Catholic Syro-Malabar Eparchy of Great Britain | Preston | A rating |
| Catimor Ltd t/a Redemption Roasters | London | A rating |
| Catling and Catling Ltd | Banbury | A rating |
| Catnip Comms Ltd | Dorchester | A rating |
| Cato Networks (UK) Limited | London | A rating |
| Catoe Sushi Delight Ltd | Nottingham | A rating |
| Catpro Beauty Ltd | London | A rating |
| Cats Eye Trading Limited | Milton Keynes | A rating |
| CatSci Ltd | Cardiff | A rating |
| Catshill Food & Wine Ltd T/A SPAR | Catshill | A rating |
| Cattanach SCIO t/a Elevate Great | Edinburgh | A rating |
| Cattle And Smoke Ltd T/A Cattle And Smoke | Leicester | A rating |
| CattleEye Ltd | Belfast | A rating |
| Cattles Specialist Woodwork Ltd | NEWPORT PAGNELL | A rating |
| Catto & Co Creative Limited | London | A rating |
| Catto International Limited | Camberley | A rating |
| Catto Limited | London | A rating |
| CATVOG DOMICILIARY SPECSAVERS LIMITED | Barry | A rating |
| Caudalie Group Limited | London | A rating |
| Caudalie UK Ltd | London | A rating |
| Caudwell Children | Keele | A rating |
| Caught & Cured Ltd | GRIMSBY | A rating |
| Caulfield & Gopalla Partnership t/a Riverside House Residential Care Home and Newnton House Residential Care Home | LONDON | A rating |
| CAULFIELDS RETAIL LTD | BISHOP'S STORTFORD | A rating |
| Caulmert Limited | Bangor | A rating |
| Caura Ltd | London | A rating |
| Cauri ltd | London | A rating |
| Causaly Ltd | London | A rating |
| CAUSEWAY COAST VINEYARD | COLERAINE | A rating |
| Causeway Green Surgery | Oldbury | A rating |
| Causeway Technologies Ltd | Gerrards Cross | A rating |
| Causeway Therapeutics Limited | Glasgow | A rating |
| CAV Ice Protection Limited | Consett | A rating |
| Cavalier Inns Ltd. | Beaconsfield | A rating |
| Cavalier Logistics UK Ltd | Feltham | A rating |
| Cavandish Supermarket Limited | Manchester | A rating |