| Allerton Windows Limited | Formby | 1996 |
| ALLERTON18 Ltd | Burnley | 2023 |
| Allertons Events Branding Limited | Oxfordshire | 2016 |
| Allertons Group Ltd | Oxfordshire | 2016 |
| Allery Holdings Limited | Manchester | 2022 |
| Alles Consulting Ltd | London | 2021 |
| Allestree Engineering Ltd | Derby | 2012 |
| Allesverloren Limited | Chelmsford | 2020 |
| Alleswell Consulting Ltd | Birmingham | 2020 |
| Allete Trading Limited | Surrey | 2006 |
| Alletsons Limited | Bridgwater | 2008 |
| Alleva Limited | Coulsdon | 2014 |
| Allevia Ltd | Southampton | 2025 |
| Alleviate Accountancy Ltd | London | 2010 |
| Alleviate Building Services and Digital Design Ltd | Dromore | 2026 |
| Alleviate Consulting Limited | Manchester | 2013 |
| Alleviate Hospitality Ltd | Bath | 2021 |
| Allevio (UK) Limited | Nottingham | 2020 |
| Allex Jenkinson Limited | Alcester | 2014 |
| Alley Marketing Consultancy (AMC) Ltd | Slough | 2013 |
| Alley Pond Close Management Company Limited | Colchester | 2016 |
| Alleybank Ltd | | 2003 |
| Alleyne and Company Limited | London | 2016 |
| Alleyne’S Influence Ltd | London | 2024 |
| Alleyoop Content Ltd | Macclesfield | 2019 |
| Alleyoop Ltd | Glasgow | 2022 |
| Alleyoop SER Ltd | Newcastle Upon Tyne | 2025 |
| Allez Accounting Ltd | Canvey Island | 2023 |
| Allez Labs Group Ltd | London | 2024 |
| Allez Labs Ltd | London | 2023 |
| Allfab Blacksmiths Ltd | 10 - 14 West Nile Street | 2002 |
| Allfocus Ltd | London | 2015 |
| Allford Bryant Business Advisors Ltd | Swindon | 2009 |
| Allford Consultancy Ltd | Shipston-On-Stour | 2025 |
| Allford Engineering Services Limited | London | 2021 |
| Allford Hall Monaghan Morris Limited | London | 2010 |
| Allfourconsulting Limited | Brandon | 2017 |
| Allfresch Group Ltd | Wolverhampton | 2013 |
| Allfutures Ltd | London | 2025 |
| Allgass Ltd | Solihull | 2026 |
| Allglass (Leaded Lights) Limited | | 1975 |
| Allgood Compliance Limited | Deal | 2021 |
| Allgood Innovations Limited | Leigh-On-Sea | 2026 |
| Allgooddesign Limited | Hailsham | 2026 |
| Allgrange Estimating Ltd | Greenford | 2024 |
| Allgrass (Scotland) Ltd | Glasgow | 2017 |
| Allguard Legal Services Ltd | St Leonards-On-Sea | 2004 |
| Allguard Services Ltd | North Leigh Business Park | 2009 |
| Allhallows Consulting Ltd | Thetford | 2013 |
| Alli Electrical Engineering Services Ltd | Coleford | 2020 |
| Alli Mason Veterinary Rehabilitation Ltd | Taunton | 2022 |
| Allia Lift Services Ltd | Glasgow Central | 2023 |
| Alliadis Europe Ltd. | Chorley | 2004 |
| Alliage Limited | Harrow | 2019 |
| Alliam Commercial Services Limited | Kilmarnock | 2017 |
| Alliance & Co. Professional Services Limited | Bradford | 2011 |
| Alliance & Cooper Legal Ltd | Ashton-Under-Lyne | 2024 |
| Alliance & Cooper Solicitors Ltd | Manchester | 2018 |
| Alliance 4 Children C.I.C. | Thornton-Cleveleys | 2025 |
| Alliance Accountancy Ltd | Harlow | 2023 |
| Alliance Accountancy Services Ltd | Ruislip | 2023 |
| Alliance Accountants (Grant & Co) Limited | Walsall | 2006 |
| Alliance Accountants (Ross-On-Wye) Limited | Walsall | 2016 |
| Alliance Accounting Services Ltd | Wokingham | 2024 |
| Alliance Advertising & Marketing Ltd | London | 2008 |
| Alliance and General Contractors Ltd. | Rainham | 2016 |
| Alliance Art UK Ltd | Tilbury | 2021 |
| Alliance Associates Limited | Leighton Buzzard | 2008 |
| Alliance Assurance Company Limited | London | 1902 |
| Alliance Automotive UK Limited | Birmingham | 1997 |
| Alliance Boots Holdings Limited | 361 Oxford Street | 2002 |
| Alliance Brook Limited | London | 2021 |
| Alliance Business Centers Network Limited | Esher | 2005 |
| Alliance Business Management Ltd | Cambridge | 2022 |
| Alliance Business Mentoring Limited | Headley | 2024 |
| Alliance CAD Services Ltd | Luton | 2026 |
| Alliance CDM Ltd. | Dalmeny | 1995 |
| Alliance Coaching Limited | Epsom | 2005 |
| Alliance Connect Ltd | London, | 2014 |
| Alliance Construction Management Ltd | Nuneaton | 2021 |
| Alliance Consult Ltd | Corby | 2025 |
| Alliance Consultancy (UK) Ltd | Leeds | 2018 |
| Alliance Consultancy Overseas Limited | Kingston Upon Thames | 2017 |
| Alliance Consultancy Services Limited | London | 2019 |
| Alliance Consulting Engineers Ltd | Bishop'S Stortford | 2025 |
| Alliance Consulting Ltd | Stockport | 2024 |
| Alliance Consulting Solutions Limited | Kirkby In Ashfield | 2014 |
| Alliance Contracting Limited | Cramlington | 2024 |
| Alliance Contracting Solutions Limited | Kirkby In Ashfield | 2014 |
| Alliance Coordination Ltd | Maidstone | 2024 |
| Alliance Creative Limited | Edinburgh | 2011 |
| Alliance Development Partners Limited | London | 2023 |
| Alliance Digital Limited | Farnham | 2024 |
| Alliance DM Ltd | Leeds | 2019 |
| Alliance Drug Development Limited | Bracknell | 2010 |
| Alliance Engraving & Lettering Co. Limited | Bristol | 1962 |
| Alliance Environment and Planning Limited | Leeds | 1998 |
| Alliance Events (Larkhall) Limited | Larkhall | 2023 |
| Alliance Factories Ltd | London | 2015 |
| Alliance Family Mediation Ltd | Ashford | 2024 |