| Alex Lawrie & Company Limited | Near Sevenoaks | 1975 |
| Alex Lawther Limited | London | 2018 |
| Alex LE Guevel Sports Consultancy Limited | Northampton | 2023 |
| Alex Legendre Consultancy Ltd | Hove | 2022 |
| Alex Lindley Limited | Nottingham | 2022 |
| Alex Linnell Consulting Limited | Crediton | 2017 |
| Alex Lloyd Wealth Management Ltd | Colchester | 2021 |
| Alex Longson Ltd | Edinburgh | 2022 |
| Alex Luck Limited | London | 2015 |
| Alex Macnaughton Photography Ltd | London | 2023 |
| Alex Magee Ltd | Edinburgh | 2025 |
| Alex Marc Associates Limited | Enfield | 2021 |
| Alex Marin Design Ltd. | London | 2021 |
| Alex Marshall Financial Consultancy Limited | Glasgow | 2018 |
| Alex Martins Development Ltd | London | 2019 |
| Alex Matthewson Consultancy Limited | London | 2024 |
| Alex MAY Accounting Services Limited | Scarborough | 2024 |
| Alex MAY Studio Ltd | Braintree | 2017 |
| Alex Mccarthy Ltd | Bedford | 2020 |
| Alex Mcghee Creative Limited | Chelmsford | 2018 |
| Alex Mcintyre Architects Limited | Nottingham | 2003 |
| Alex Mcintyre Limited | St Austell | 2023 |
| Alex Merry Consultancy Limited | Bishop'S Stortford | 2013 |
| Alex Miller Book-Keeping Services Limited | Dorking | 2002 |
| Alex Miller Photography Limited | Walsall | 2016 |
| Alex Mills Digital Limited | Wilmslow | 2020 |
| Alex Mitris Ltd | London | 2020 |
| Alex Mortgages Ltd | Colchester | 2019 |
| Alex Mortiboys Works Limited | Fareham | 2024 |
| Alex Morton Consulting Limited | Rye | 2018 |
| Alex Moss Media Ltd | Erith | 2021 |
| Alex Mulder Design Ltd | Brighton | 2016 |
| Alex Mullan Ltd | Hove | 2025 |
| Alex Munday Planning Ltd | Eastleigh | 2026 |
| Alex Murray Holdings Limited | Helensburgh | 2005 |
| Alex Nacu Architects Ltd | London | 2018 |
| Alex Nelson Design Ltd | Nottingham | 2025 |
| Alex Nichols Consulting Limited | Ewelme | 2014 |
| Alex Nicoll Business Management Limited | Shoreham-By-Sea | 2010 |
| Alex North Consulting Limited | Saffron Walden | 2024 |
| Alex Oscar Law Limited | London | 2024 |
| Alex OTT Architecture Ltd | Horley | 2022 |
| Alex Ozegovic Limited | London | 2025 |
| Alex Page Ltd | Essex | 2019 |
| Alex Parker (2013) Limited | Lymm | 2013 |
| Alex Parker Limited | Lymm | 2005 |
| Alex Payne Consulting Limited | Thornton-Cleveleys | 2021 |
| Alex Payne Ltd | Henlow | 2024 |
| Alex Pearson Architect Limited | Dundee | 2019 |
| Alex Peck Group Ltd. | Mildenhall | 2019 |
| Alex Plant Limited | Cowbridge | 2003 |
| Alex Potts Limited | Wirral | 2019 |
| Alex Power & Control Ltd | Leicester | 2026 |
| Alex Purcell Studio Ltd | London | 2022 |
| Alex Quinn & Partners Ltd. | Edinburgh | 2004 |
| Alex Rail Limited | London | 2023 |
| Alex Ravelo Design Ltd | Ilminster | 2023 |
| Alex Ricketts Ltd | Eastleigh | 2019 |
| Alex Rius Consultants Limited | Cambridge | 2024 |
| Alex Robinson Limited | Norwich | 2011 |
| Alex Roldan Photography Ltd | York | 2018 |
| Alex Ropes Ltd | London | 2017 |
| Alex Rorison Ltd | London | 2023 |
| Alex Rosen Associates Limited | Exeter | 2003 |
| Alex Ross Ltd | Lincoln | 2025 |
| Alex Rossiter Limited | London | 2024 |
| Alex Ryden Consulting Limited | Diss | 2025 |
| Alex Sandeman Design Ltd | Salisbury | 2023 |
| Alex Scott Marine Consultancy Ltd | Prescot | 2006 |
| Alex Serviceteam Limited | London | 2007 |
| Alex Sexton Ltd | Billingham | 2024 |
| Alex Shillingford Limited | London | 2026 |
| Alex Shrimpton Consulting Ltd | St. Albans | 2025 |
| Alex Skinner Design Limited | Redditch | 2014 |
| Alex Slors Consulting Ltd | Orpington | 2008 |
| Alex Smith Wealth Management Limited | Saltash | 2023 |
| Alex Solicitors Limited | London | 2024 |
| Alex Solomon Consulting Ltd | Bath | 2021 |
| Alex Solutions 14 Ltd | Hounslow | 2020 |
| Alex Sparrow Limited | Stafford | 2013 |
| Alex Spears Marketing Ltd | London | 2025 |
| Alex Spencer Design Ltd | Ruislip | 2011 |
| Alex Spillius Associates Ltd | London | 2017 |
| Alex Squared Ltd | Nottingham | 2023 |
| Alex Stage Ltd | Weymouth | 2025 |
| Alex Stoneman Photography Ltd | Bristol | 2025 |
| Alex Strasman Design Ltd | Warminster | 2014 |
| Alex Styles Photography Ltd | Pattingham | 2012 |
| Alex Sullivan Design & Art Direction Ltd | London | 2019 |
| Alex Sutton PR Ltd | Liverpool | 2020 |
| Alex Tanas Limited | London | 2013 |
| Alex Tart Architects Limited | Teddington | 2013 |
| Alex Tech Solutions Ltd | Hull | 2018 |
| Alex Telfer Photography Limited | Newcastle Upon Tyne | 2002 |
| Alex Tenters Photography Limited | Maidstone | 2019 |
| Alex Thomas Financial Planning Limited | Harpenden | 2018 |
| Alex Toni Creative Ltd | London | 2018 |
| Alex Truesdale Wills Limited | Cobham | 2010 |
| Alex UK Consulting Ltd | London | 2022 |
| Alex UK Limited | Uxbridge | 2000 |