| Alessandro Consultants Ltd | Northampton | 2026 |
| Alessandro Cooper Consultancy Ltd | Warlingham | 2022 |
| Alessandro Isola Limited | London | 2014 |
| Alessandro Molent Studio Ltd | London | 2022 |
| Alessandro Persano Financial Consulting Ltd | Northallerton | 2026 |
| Alessandro Totoro Ltd | Birmingham | 2020 |
| Alessandro Tozzi Sales Ltd | London | 2025 |
| Alessandro Verdenelli Restaurant Consultant Ltd | London | 2019 |
| Alessandro Zavarise Ltd | Crowborough | 2020 |
| Alessco Ltd | Belfast | 2010 |
| Alessia Limited | Bromley | 2013 |
| Alessia Miro Interiors Ltd | London | 2022 |
| Alessian Limited | London | 2019 |
| Alessio D'Angelo Studio Ltd | London | 2018 |
| Alessio LA Ruffa Photography Limited | London | 2021 |
| Alesso Law Limited | Salford | 2026 |
| Alesta UK Ltd | London | 2025 |
| Alesvi Advisors Limited | Fareham | 2024 |
| Alesway Limited | Leeds | 1996 |
| Alet Marketing Limited | Belper | 2017 |
| Aleta Biotherapeutics Ltd | Altrincham | 2026 |
| Aleta Consulting Ltd | London | 2015 |
| Aleta Marketing Ltd | Preston | 2021 |
| Aleta Studio Ltd | Kingston Upon Thames | 2021 |
| ALETALAN1206 Limited | Swansea | 2024 |
| Aleteia Consulting Limited | London | 2025 |
| Aletes Consulting Ltd | Newtownabbey | 2020 |
| Aletha Limited | London | 2023 |
| Alethea & Co (London) Limited | Sheffield | 2015 |
| Alethea Consulting Limited | Bedford | 2005 |
| Alethea Law Limited | Leamington Spa | 2025 |
| Aletheia Accounting Services Ltd | Manchester | 2023 |
| Aletheia Audit Limited | Wolverhampton | 2026 |
| Aletheia Consultancies Ltd | Carrickfergus | 2018 |
| Aletheia Consultancy Limited | Hackleton | 2013 |
| Aletheia Consulting Ltd | Dewsbury | 2018 |
| Aletheia Edtech R&D (UK) Ltd | London | 2025 |
| Aletheia Forensics International Ltd | London | 2025 |
| Aletheia Imaging Solutions Limited | Manchester | 2021 |
| Aletheia Integrated Management Systems Ltd | Gloucester | 2012 |
| Aletheia International Ltd | Reigate | 2024 |
| Aletheia Intuitive Investment Limited | Kendal | 2025 |
| Aletheia Limited | London | 2022 |
| Aletheia Serene UK Ltd | Arundel | 2022 |
| Aletheia Strategic Ltd | Greenford | 2026 |
| Aletheo Contracting & Consultancy Ltd | Hessle | 2025 |
| Aletheon Ltd | Aberdeen | 2025 |
| Alethes Ltd | London | 2024 |
| Alethia Data Science Limited | London | 2017 |
| Alethia Health Ltd | Portsmouth | 2025 |
| Alethia Ltd | Carlisle | 1999 |
| Alethiarc Limited | Nantwich | 2022 |
| Alethio Ltd | London | 2022 |
| Alethio Therapeutics Limited | Abingdon | 2021 |
| Alethira Ltd | London | 2025 |
| Aletho Consulting Ltd | Llandovery | 2013 |
| Alethogen Ltd | Bolton | 2023 |
| Alethos Business Solutions Ltd | Huddersfield | 2025 |
| Alethra Ltd | Nottingham | 2026 |
| Aletis Consulting Ltd | London | 2021 |
| Aletomen Limited | Haddington | 2026 |
| Aleur Limited | Romford | 2014 |
| Aleuron Associates Ltd | London | 2023 |
| Aleva & Co Accountants Ltd | Romford | 2023 |
| Aleva Consulting Ltd | London | 2025 |
| Aleva Ltd | Newport | 2023 |
| Alevia Consulting Ltd | Lytham St.Annes | 2023 |
| Alevin Therapeutics Limited | Cambridge | 2022 |
| Alevitas Advisory Ltd | London | 2025 |
| Alew Holdco Limited | Alderley Edge | 2017 |
| Alex & BEN Ltd | Motherwell | 2018 |
| Alex & Co Accountancy Ltd | London | 2006 |
| Alex & Co Accountants | London | 2014 |
| Alex & Jane Adkins Trading Limited | Liverpool | 2016 |
| Alex + Plex Ltd | London | 2019 |
| Alex Adiele Ltd | Edinburgh | 2021 |
| Alex Advisory Group Ltd | London | 2026 |
| Alex Afnan Consulting Ltd | Pinner | 2000 |
| Alex Aldrich PR Ltd | Spalding | 2022 |
| Alex Allen Creative Ltd | Crewe | 2019 |
| Alex Arens Ltd | London | 2024 |
| Alex Arundel Studio Ltd | York | 2026 |
| Alex Ashdjian Design Ltd | London | 2019 |
| Alex Automotive Limited | Camberley | 2017 |
| Alex Ayin Advisory Ltd | London | 2018 |
| Alex B Engineering Limited | Gainsborough | 2025 |
| Alex Baciu Design Limited | London | 2017 |
| Alex Bacon Ltd | Dronfield | 2017 |
| Alex Barbacorta Media Limited | Bury | 2024 |
| Alex Barclay HSE Associates Limited | Dundee | 2018 |
| Alex Barker Ltd | London | 2024 |
| Alex Barnes & Associates Limited | London | 2016 |
| Alex Barriff Consultancy Ltd | London | 2025 |
| Alex Base Ltd | London | 2018 |
| Alex Baskerville Limited | Clarkston | 2017 |
| Alex Batchelor Limited | Huddersfield | 2020 |
| Alex Baumann Creative Ltd | London | 2019 |
| Alex Beattie Limited | Southwark | 2020 |
| Alex Beckett Photography Limited | Cambridge | 2013 |
| Alex Bell (Dental Supplies) Limited | Coventry | 1983 |