| Black & White Group Limited | Gloucester | A rating |
| Black & White Tints Ltd | Limehouse | A rating |
| Black and Blum Limited | London | A rating |
| Black and Milk Residential LTD | London | A rating |
| Black and White Engineering Limited | Newcastle upon Tyne | A rating |
| Black and White Live | Harrow on the Hill | A rating |
| Black and Yellow Construction Limited | Crawley | A rating |
| Black Bear Burger Ltd | Okehampton | A rating |
| Black Bear Pictures UK Limited | London | A rating |
| Black Bears Polo Team | Shiplake | A rating |
| Black Box Bakery Ltd | Newcastle | A rating |
| BLACK BOX DONUTS LTD | Newcastle | A rating |
| Black Box Media Consultancy Limited | London | A rating |
| BLACK BOX MEDIA MARKETING LTD | Southampton | A rating |
| Black Box Network Services (UK) Limited | Reading | A rating |
| Black Boy (caernarfon) Ltd | Caernarfon | A rating |
| BLACK BRICK PROPERTY SOLUTIONS LLP | London | A rating |
| Black British Golfers CIC | London | A rating |
| Black Bull Biochar Ltd | Manchester | A rating |
| Black Bull Fitness Limited | Huddersfield | A rating |
| Black Cat Building Consultancy Limited | Manchester | A rating |
| Black Cat Maldon Ltd | London | A rating |
| Black Cobra Ltd | Staines-Upon-Thames | A rating |
| Black Country Healthcare NHS Foundation Trust | Wolverhampton | A rating |
| Black Cow Technology Limited | Oxford | A rating |
| Black Diamond Agency Ltd | London | A rating |
| Black Diamond Capital Management Limited | London | A rating |
| BLACK EAGLE BESIKTAS LIMITED | London | A rating |
| Black Eagle Scaffolding Ltd | Hertfordshire | A rating |
| Black Eden Ltd | Norwich | A rating |
| Black Emerald Ltd | London | A rating |
| Black Eye Bens Ltd | Manchester | A rating |
| BLACK FIRE SOLUTIONS LTD | LONDON | A rating |
| BLACK FLASH PROMOTIONS LTD | MANCHESTER | A rating |
| BLACK HIGHLANDS LTD | HUDDERSFIELD | A rating |
| Black Isle Timber Harvesting Limited | Fortrose, Rosemarkie | A rating |
| Black Kite Studios Ltd | London | A rating |
| Black Knight Football Club UK Limited | Bournemouth | A rating |
| Black Knights Parachute Centre | Lancaster | A rating |
| Black Label Creations | Frimley | A rating |
| Black Lion Capital LLP | London | A rating |
| BLACK OPAL CONSULTING LTD | London | A rating |
| black orchid (tattoo & body piercing) Ltd | skegness | A rating |
| Black Pearl Homes Limited | London | A rating |
| Black Pearl Medical Ltd | Birmingham | A rating |
| Black Peppers Whitchurch Ltd | Bristol | A rating |
| Black Piano Limited | Bishop's Stortford | A rating |
| Black Pomegranate Limited | London | A rating |
| Black Revolver Films | Northampton | A rating |
| Black Rock Restaurant Group Ltd | Brighton | A rating |
| Black Rock Security & FM | Holmfirth | A rating |
| Black Rock Vets Ltd | Burnham on Sea | A rating |
| BLACK ROOSTER FRANCHISING LTD | Glasgow | A rating |
| BLACK ROSES SUPPORT C.I.C. | Slough | A rating |
| Black Salt Sheen Limited T/A Black Salt Sheen | London | A rating |
| BLACK SEA CONTRACTING LIMITED | Hayes | A rating |
| BLACK SMITH SECURITY LIMITED | London | A rating |
| Black Stone Construction, Trading & Consultancy Ltd | Croydon | A rating |
| Black Sun Limited | London | A rating |
| Black Sun Ltd | London | A rating |
| Black Swan Capital | London | A rating |
| Black Swan Data Limited | London | A rating |
| Black Swan Group Ltd | East Grinstead | A rating |
| Black Swan International | Norwich | A rating |
| Black Temple Limited | London | A rating |
| Black Tomato Ltd | London | A rating |
| Black Volta Ventures (UK) Limited | London | A rating |
| BLACK WHALE LIMITED | London | A rating |
| Black Women's Resource Centre Watoto Preschool Ltd | SHEFFIELD | A rating |
| Blackadder Corporation Limited | Chesterton | A rating |
| BLACKAPPLE SOLUTIONS LTD | HUDDERSFIELD | A rating |
| Blackballed Ltd | Manchester | A rating |
| Blackbaud Europe Ltd | London | A rating |
| Blackberry Hill Limited | London | A rating |
| BlackBerry UK Limited | Maidenhead | A rating |
| Blackbird Bakery Limited | London | A rating |
| Blackbird News | Leicester | A rating |
| BLACKBIRD TRADING BHAM LTD | Birmingham, | A rating |
| BLACKBOARD (UK) LIMITED | Hampton | A rating |
| Blackbridge Communications LTD | London | A rating |
| Blackbrook Capital (Europe) Limited | London | A rating |
| Blackbrook Cottages Ltd | Colchester | A rating |
| Blackbrook house care Ltd | Fareham | A rating |
| Blackbullion Limited | London | A rating |
| Blackburn & Co Project Services Limited | London | A rating |
| Blackburn Diocesan Board of Finance Ltd | Blackburn | A rating |
| Blackburn Embroidery | Accrington | A rating |
| Blackburn Grocers Ltd | Blackburn | A rating |
| BLACKBURN HOME CARE SERVICES LIMITED | Darwen | A rating |
| Blackburn International (UK) Limited | Surrey | A rating |
| Blackburn Property Management Ltd | Blackburn | A rating |
| Blackburn Road Medical Centre | Batley | A rating |
| Blackburn Rovers Ladies Football Club | Blackburn | A rating |
| BLACKBURN SMILECARE LTD | BLACKBURN | A rating |
| BLACKBURN U K TRUST | BLACKBURN | A rating |
| BLACKCOUNTRY MOTORS LTD | Oldbury | A rating |
| Blackdice Healthcare Limited | Devon | A rating |
| Blacketts Medical Practice | Darlington | A rating |
| Blackfaulds Nursing Home Limited | Falkirk | A rating |
| Blackfen School for Girls | Sidcup | A rating |
| BlackFin Capital Partners UK Ltd | London | A rating |
| Blackfinch Financial Ltd | Gloucester | A rating |
| Blackford Casks Ltd | London | A rating |
| Blackfriars Hotels Limited | London | A rating |
| Blackgold Excel Ltd | Glasgow | A rating |
| Blackhall Powis | Glasgow | A rating |
| Blackhawk Network EMEA Limited | Hemel Hempstead | A rating |
| Blackheath and Charlton Baptist Church | London | A rating |
| Blackheath Cricket Club | London | A rating |
| BLACKHEATH FOODS LTD | Halesowen | A rating |
| Blackheath High School GDST | London | A rating |
| Blackheath Rugby Limited | London | A rating |
| Blackheath Standard PMS | London | A rating |
| BLACKHORN PROPERTIES LIMITED | ROTHERHAM | A rating |
| Blackhouse Media (BHM) Limited | Edinburgh | A rating |
| Blackhouse Media (BHM) Ltd | Edinburgh | A rating |
| Blackland Park Exploration Limited | Lincoln | A rating |
| BLACKLANE HAVN UK LTD | London | A rating |
| BLACKLEY SERVICE STATION LTD | Manchester | A rating |
| Blackline Systems Ltd | London | A rating |
| Blacklion Law LLP | London | A rating |
| Blacklist Creative Ltd | London | A rating |
| BLACKLIST LOUNGE LONDON LIMITED | London | A rating |
| Blackmagic Design Ltd | Knutsford | A rating |
| Blackman Terry Accountants Ltd | Haywards Heath | A rating |
| Blackmoor Investment Partners Limited | London | A rating |
| BLACKMORE SERVICES LIMITED | BRISTOL | A rating |
| Blackpool and The Fylde College | Blackpool | A rating |
| BLACKPOOL COUNCIL | BLACKPOOL | A rating |
| Blackpool Cricket Club | Blackpool | A rating |
| Blackpool Eats Limited | Blackpool | A rating |
| Blackpool Estates Ltd | Blackpool | A rating |
| Blackpool Football Club | Blackpool | A rating |
| BLACKPOOL PARKS LIMITED | BLACKPOOL | A rating |
| Blackpool Pleasure Beach Ltd | Blackpool | A rating |
| Blackpool Raja Ltd t/a Blackpool Central Hotel | Blackpool | A rating |
| BLACKPOOL SUPERSTORE LTD | Blackpool | A rating |
| Blackpool Teaching Hospitals NHS Foundation Trust | Blackpool | A rating |
| Blackpool Trading Ltd | Blackpool | A rating |
| Blackrock Construction Group Ltd | Moodiesburn | A rating |
| BLACKROCK INVESTMENT MANAGEMENT (UK) LIMITED | LONDON | A rating |
| BLACKROCK RECRUITMENT SERVICES LIMITED | Ilford | A rating |
| Blackrock Traders Ltd t/a Creams Cafe Morden | Morden | A rating |
| Blackrod Cricket Club | Bolton | A rating |
| BLACKROD HOUSE LIMITED | Bolton, | A rating |
| Blackrow Engineering Co Ltd | Grimsby | A rating |
| Blacks legal LTD | Ilford | A rating |
| Blacks Solicitors LLP | Leeds | A rating |
| Blacks Visual Merchandising Limited | Wetherby | A rating |
| BLACKSEA OFF LICENCE LTD | Newcastle upon Tyne | A rating |
| Blacksheep Design Collectives limited | deal | A rating |
| BLACKSMITH CYCLES LTD | London | A rating |
| BLACKST1 MEDIA LTD | London | A rating |
| Blackstar Amplification Ltd | Northampton | A rating |
| Blackstar Capital Europe Limited | London | A rating |
| BLACKSTOCK CONSULTING LTD | London | A rating |
| Blackstock Dental Care | London | A rating |
| BLACKSTONE AGENTS LTD | Bournemouth | A rating |
| BLACKSTONE DESIGN LTD | LONDON | A rating |
| Blackstone Europe LLP | London | A rating |
| BLACKSTONE FOODS LIMITED | London | A rating |
| BLACKSTONE LEGAL SERVICES LIMITED | London | A rating |
| Blackstone Motors Limited | West Drayton | A rating |
| Blackstone Properties Group Ltd | Birmingham | A rating |
| BLACKSTONE SHIPPING UK LIMITED | Watford | A rating |
| Blackstones Estates Ltd | London | A rating |
| Blackstown Holdings Limited | Walton-On-Thames | A rating |
| Blackstream Ltd (trading as Balmacara Mains ) | By Kyle of Lochalsh | A rating |
| Blackthorn Health Centre | SOUTHAMPTON | A rating |
| Blackthorn Ltd | Chipping Norton | A rating |
| Blackthorn Medical Centre | Maidstone | A rating |
| Blackthorn Trust | Maidstone | A rating |
| BLACKTRACE HOLDINGS LIMITED | Royston | A rating |
| BLACKWALL SECURITY LTD | London | A rating |
| Blackwater Academy LTD | Birmingham | A rating |
| BLACKWATER CAPITAL LTD | Uxbridge | A rating |
| BLACKWATER DENTAL SURGERY & IMPLANT CENTRE LTD | BLACKWATER | A rating |
| BLACKWATER TECH LTD | London | A rating |
| Blackwater Valley Veterinary Centres Ltd | Camberley | A rating |
| Blackwell Associates Limited | Belfast | A rating |
| Blackwell Waltmaier Ltd | Barrow | A rating |
| Blackwells Chemist Limited | Beckenham | A rating |
| Blackwood Capital Group (UK) Limited | London | A rating |
| Blackwood Engineering Ltd | Aberbeeg | A rating |
| Blackwood Homes | Edinburgh | A rating |
| Blackwood Recruitment LLP | London | A rating |
| Blackwood Visionplus t/a Specsavers Limited | Blackwood | A rating |
| Blade Energy Partners Ltd | Aberdeen | A rating |
| Bladebug Limited T/A BladeBUG | London | A rating |
| BLADEZ TOYZ LIMITED | MARLOW | A rating |
| Bladon Technologies Ltd | Warwick | A rating |
| Blaenmarlais Care Ltd | Narberth | A rating |
| Blagrove Underwriting Agency Ltd | London | A rating |
| Blaiket Mains Dairy Co Ltd | Dumfries | A rating |
| Blair Drummond Estates Ltd | Stirling | A rating |
| Blair Drummond Smiddy Farm Shop | Stirling | A rating |
| Blair Ecosse Management Ltd t/a The Old Manse of Blair | Pitlochry | A rating |
| Blaircourt Equine Veterinary Clinic Ltd | Chelmsford | A rating |
| Blairgowrie Physiotherapy and Sports Injury Clinic Ltd | Blairgowrie | A rating |
| BLAIRGROCERIES LIMITED | Hurlford | A rating |