| ATASAN & CO. LTD | LONDON | A rating |
| ATAVA LIMITED | LONDON | A rating |
| ATB CONSTRUCTION LTD | Kent | A rating |
| ATB Foods (NW) Ltd T/A Al Taiba Bukhari | Manchester | A rating |
| ATB Group UK Limited | Norwich | A rating |
| ATB TRADING LTD | Rotherham | A rating |
| ATC Brokers Ltd | London | A rating |
| ATC CARPETS & FURNITURE LTD | Southall | A rating |
| ATC FUEL LTD | Middlesex | A rating |
| ATC Holdings Limited | Poyle | A rating |
| ATC REPAIR CENTRE LIMITED | Rotheram | A rating |
| ATC SCAFFOLDING SUPPLIES LIMITED | Camberley | A rating |
| ATC Systems Limited | Newtownabbey | A rating |
| ATC Trading Int Ltd | Greenford | A rating |
| ATC Traditional Floors and Doors Ltd | Monmouth | A rating |
| Atcha Holdings Limited | London | A rating |
| Atchem Ltd T/A Dev's Chemist | London | A rating |
| ATCL Limited | Middlesex | A rating |
| ATCO ESTATES LIMITED | ESSEX | A rating |
| Atcore Technology Limited | Slough | A rating |
| ATD Fourth World Ltd | London | A rating |
| ATEC DESIGN & RENOVATION LIMITED | MANCHESTER | A rating |
| Ateca Limited | London | A rating |
| Atech Support Ltd | Marlow | A rating |
| ATEGI LIMITED | RHYDYFELIN | A rating |
| ATELIER ATHEM LIMITED | London | A rating |
| ATELIER BRISAC LTD | London | A rating |
| Atelier Gooch Ltd | London | A rating |
| Atelier JI Limited | London | A rating |
| Atelier One Ltd | London | A rating |
| Atelier Set Limited | London | A rating |
| ATELIER TECHNOLOGY LIMITED | London | A rating |
| Atelier Ten (Scotland) Ltd | Glasgow | A rating |
| Atelier Ten London Limited | London | A rating |
| Atelier U W A Architects Limited | London | A rating |
| ATELIER WREN LTD | LONDON | A rating |
| Atelier001 Limited | London | A rating |
| ATELIERS LONDON LTD | LONDON | A rating |
| Atellior Limited | London | A rating |
| ATEME UK LTD | LONDON | A rating |
| Atempo Growth | London | A rating |
| ATEN COMMUNICATIONS UK LTD | London | A rating |
| ATESCO CONSULTANCY LTD | London | A rating |
| aTest Limited | Coventry | A rating |
| Atex Media Limited | Bristol | A rating |
| Ateyant Transport Ltd | Leicester | A rating |
| ATEZ UK SOFTWARE TECHNOLOGIES LTD | London | A rating |
| ATFGROUP LIMITED T/A IT House UK | London | A rating |
| ATG Aerospace Ltd | Stevenage, Hertfordshire | A rating |
| ATG Airports Limited | Warrington | A rating |
| ATG Entertainment Limited | Woking | A rating |
| Athanasiadis & Kotsiou Ltd | Eastbourne | A rating |
| Athans International | brentwood | A rating |
| ATHELSTANONE PTY LTD | Sheffield | A rating |
| Athena Advisers Ltd | London | A rating |
| Athena Advisory Solutions Ltd | Leicester | A rating |
| Athena Care (Ormskirk) Limited | Lancashire | A rating |
| Athena Care Homes (Monmouth) Limited | Laindon, | A rating |
| Athena Dental Laboratory Limited | Northampton | A rating |
| Athena Engineering Limited | Preston | A rating |
| Athena Events Limited | Leicester | A rating |
| Athena Healthcare (Church Road) Limited | Formby | A rating |
| Athena Healthcare (LSA Two) Limited | Lytham St Annes | A rating |
| Athena Healthcare (Oxford Road) Limited | Birkdale | A rating |
| Athena Housing and Support Limited | Kempston | A rating |
| ATHENA PETERS INVESTMENTS LIMITED | Staines-Upon-Thames | A rating |
| Athena PTS | Ulverston | A rating |
| Athena Racing Limited | London | A rating |
| Athena Trading Limited | Chislehurst | A rating |
| Athena Wear Limited | Holt | A rating |
| Athenaeum Partners UK Limited | London | A rating |
| ATHENEUM LIMITED | London | A rating |
| Atheon Analytics Limited | Milton Keynes | A rating |
| Ather Medicals Limited | Hove | A rating |
| Atherapy Limited | Leeds | A rating |
| Atherden Fuller Leng Limited | Manchester | A rating |
| Atheria Law Ltd | London | A rating |
| ATHERTON & PARTNERS LIMITED | WIRRAL | A rating |
| Atherton Brooks LLP | Epsom | A rating |
| Atherton Cricket Club | Atherton | A rating |
| ATHI UK RETAIL LTD | NORMANTON | A rating |
| Athina Chope Ltd | Gloucestershire | A rating |
| Athina Limited | Staines-upon-Thames | A rating |
| Athiran Uk Limited | Dereham | A rating |
| Athium Limited | Warwick | A rating |
| Athla Capital Management Ltd | Bath | A rating |
| Athlete Edge Fitness Solution Ltd | Cardiff | A rating |
| Athletes' Performance UK Limited | London | A rating |
| Athletica Health Ltd | York | A rating |
| Athlon Mobility Services UK Limited | Milton Keynes | A rating |
| Athlone Care Ltd | Dartford | A rating |
| Athlone Investment Management LLP | LONDON | A rating |
| Atholl Road Design Ltd. | Pitlochry | A rating |
| Athora UK Services Limited | London | A rating |
| Athorpe Health Care Limited | Dinnington | A rating |
| ATHT LIMITED | LONDON | A rating |
| ATHULA DASSANA MULTI-CULTURAL BUDDHIST COMMUNITY CENTRE | FELTHAM | A rating |
| ATHVIKA LTD | Morden | A rating |
| Athy Retail Ltd | Merthyr Tydfil | A rating |
| ATI Fibrenet Limited | London | A rating |
| ATI2UDE CARE LIMITED T/A TY PENTWYN CARE HOMES | TREORCHY | A rating |
| Atic Limited | London | A rating |
| ATIF CONSULT LTD | LONDON | A rating |
| ATIF STORE LTD T/A ATIF SUPER STORE | OXFORD | A rating |
| Atif Superstore Limited | Woking | A rating |
| ATIF SWEETS LTD | Birmingham, | A rating |
| Atil News Limited | London | A rating |
| ATIL Trading Limited | Warborough, Wallingford | A rating |
| ATITECH UK | London | A rating |
| Atitlan Asset Management Limited | London | A rating |
| Atkin Trustees Limited | Solihull | A rating |
| Atkins & Potts Ltd | Newbury | A rating |
| Atkins Brickwork Limited | Chessington | A rating |
| Atkins Care Services Ltd | Walton on Thames | A rating |
| Atkins Walters and Webster Limited | Bristol | A rating |
| ATKINS WAY STORE | HINCKEY | A rating |
| Atkinson Health Centre Practice | Barrow-in-Furness | A rating |
| AtkinsRealis PPS Limited | London | A rating |
| AtkinsRealis UK Limited | London | A rating |
| ATL MARINE & ENERGY LIMITED | London | A rating |
| ATL RESOURCE CO. LTD | London | A rating |
| ATLABS INFOTECH LTD | walthamabbey | A rating |
| Atlanta Healthcare Limited | Norwich | A rating |
| Atlanta Insurance Intermediaries Limited | Salford | A rating |
| Atlantamed Ltd | Kingston Upon Thames | A rating |
| Atlante UK | London | A rating |
| Atlantic Biogas Ltd | St Albans | A rating |
| ATLANTIC BRIGHTSTONE LTD | London | A rating |
| ATLANTIC COOLING LIMITED | Bolton | A rating |
| Atlantic Distributions Ltd | London | A rating |
| Atlantic Dwellings Ltd | Peterston-Super-Ely | A rating |
| ATLANTIC ELECTRONICS LIMITED | London | A rating |
| Atlantic Green UK Limited | Reading | A rating |
| Atlantic Group International Limited | Bristol | A rating |
| Atlantic House Group Limited | London | A rating |
| Atlantic Law Ltd | LONDON | A rating |
| ATLANTIC LINEN SERVICES LIMITED | Warmley | A rating |
| Atlantic Lodge (Housing) Limited | London | A rating |
| ATLANTIC MEDICAL GROUP | PENZANCE | A rating |
| ATLANTIC MONEY LIMITED | LONDON | A rating |
| Atlantic Pacific Global Logist | Basildon | A rating |
| ATLANTIC PAYROLL SOLUTIONS LTD | London | A rating |
| Atlantic Projects Company (UK) Ltd | Derby | A rating |
| Atlantic Pumps Ltd | Chesterfield | A rating |
| Atlantic Renewables | Altrincham | A rating |
| Atlantic Springs Consulting Ltd | Birmingham | A rating |
| Atlantic Star Battersea Limited T/A Tashas Cafe | London | A rating |
| Atlantic Travel (GB) Limited | Bolton | A rating |
| Atlantic Trawlers Kilkeel Ltd | Newry | A rating |
| ATLANTIC UK INSURANCE AND REINSURANCE BROKERS LTD | LONDON | A rating |
| Atlantica Sustainable lnfrastructure Limited | London | A rating |
| Atlantico UK Ltd | CROYDON | A rating |
| Atlantida Development Ltd | London | A rating |
| Atlantis AV Solutions Ltd | Malmesbury | A rating |
| Atlantis Building Supplies Ltd | Reading | A rating |
| Atlantis Commodities Trading (UK) Ltd | Cheshire | A rating |
| Atlantis Corporation (Imports) LTD | Rochdale | A rating |
| Atlantis Health UK Limited | London | A rating |
| Atlantis Lounge and Resturant Ltd | Slough | A rating |
| Atlantis Medicare (Bridgeness) Limited | Bo'ness | A rating |
| ATLANTIS MIF LTD | Oxford | A rating |
| Atlantis Operations (UK) Ltd | London | A rating |
| Atlantis Pizza (Holmfirth) Ltd | Huddersfield | A rating |
| ATLANTIS PROPERTIES LTD | harrow | A rating |
| Atlantis Resources (Scotland) Limited | Edinburgh | A rating |
| ATLANTIS TECHNOLOGY SOLUTIONS LIMITED | LONDON | A rating |
| ATLAR TECHNOLOGY LTD | London | A rating |
| Atlas Air, Inc | Farnborough | A rating |
| ATLAS AUTOMATION SYSTEMS LTD | Cheltenham | A rating |
| Atlas Automobiles Uk Ltd | Windsor | A rating |
| Atlas Care Homes Ltd | Newcastle Upon tyne | A rating |
| Atlas Care Services Limited t/a Atlas Care | Peterborough | A rating |
| Atlas Cars Limited | London | A rating |
| Atlas Converting Equipment Limited | Bedford | A rating |
| Atlas Copco Bolting Solutions (Tentec Ltd) | Wolverhampton | A rating |
| Atlas Copco IAS UK Limited | Deeside | A rating |
| Atlas Copco UK Holdings Ltd | Hemel Hempstead | A rating |
| Atlas Cranes UK Limited | Bradford | A rating |
| ATLAS ELEKTRONIK UK Limited | Dorchester | A rating |
| ATLAS ENDOSCOPY LIMITED | Leeds | A rating |
| Atlas FRM (UK) Ltd | London | A rating |
| ATLAS GLAZING LTD | BIRMINGHAM | A rating |
| Atlas Health Group Limited | Norwich | A rating |
| Atlas ICS Limited | London | A rating |
| Atlas Impact Limited | London | A rating |
| Atlas Infrastructure Partners (UK) Limited | London | A rating |
| Atlas Interactive Management Ltd | London | A rating |
| Atlas Mapping Limited | Peterborough | A rating |
| ATLAS MARINE CONSULTANCY LTD | London | A rating |
| Atlas Market Ltd | London | A rating |
| Atlas Merchant Capital Holdings UK Limited | London | A rating |
| Atlas Petroleum Ltd | Hertfordshire | A rating |
| Atlas Services Group Energy Ltd | Bristol | A rating |
| Atlas Support Limited | Chatham | A rating |
| ATLAS SURVEYS LLP | NEWPORT | A rating |
| Atlas Technica UK Ltd | London | A rating |
| Atlas Technology Solutions UK Limited | London | A rating |
| Atlas UAV Ltd | London | UK Expansion Worker: Provisional |
| Atlas Vehicles Management Limited | London | A rating |
| Atlas Workplace Services Limited | Milton Keynes | A rating |