| Alex the Big Limited | Birmingham | 2020 |
| Alex the Builder Ltd | Barking | 2014 |
| Alex Top Services Ltd | Rainham | 2015 |
| Alex Tracking Ltd | Basildon | 2016 |
| Alex Tulloch Joiners Ltd. | Glasgow | 2003 |
| Alex U Constructions Limited | London | 2026 |
| Alex UK Construction Ltd | Hayes | 2024 |
| Alex Underhill Carpentry Ltd | Caerphilly | 2026 |
| Alex VIN DEV Limited | Rainham | 2021 |
| Alex Ward Electrical Contractors Limited | Southam | 2017 |
| Alex Wood Building and Roofing Limited | Halifax | 2013 |
| Alex Woodhouse Carpentry Ltd | Chatham | 2022 |
| Alex Woodwork Ltd | Evesham | 2018 |
| Alex Wright Developments Limited | Preston | 2022 |
| Alex Wright Roofing Ltd | Leamington Spa | 2023 |
| Alex&Alex Ltd | Rugby | 2023 |
| Alex&Co Builders Limited | Peterborough | 2023 |
| Alex&Co Ltd | Harrow | 2017 |
| Alex&Dan Ltd | Redditch | 2023 |
| Alex&Denis Contraction Ltd | London | 2025 |
| Alex&Luiza Ltd | London | 2025 |
| Alex&M Steel Ltd | Ilford | 2025 |
| Alex&Roxi Construction Ltd | Erdington, Birmingham | 2018 |
| Alex&Sons Construction Ltd | Feltham | 2020 |
| Alex's Decorating Limited | High Wycombe | 2025 |
| Alex's Top END Decorators Ltd | London | 2025 |
| Alex's Windows Ltd | London | 2017 |
| Alex's World Limited | Southampton | 2019 |
| Alex-Facades & Co Ltd | London | 2019 |
| Alex.K&Son Ltd | Liverpool | 2024 |
| ALEX06 Ltd | Sutton | 2008 |
| ALEX1914 Ltd | Grays | 2023 |
| ALEX2023 Limited | London | 2023 |
| ALEX72 Drylining Ltd | London | 2023 |
| ALEX98 Ltd | Romford | 2016 |
| Alexa Builders Ltd | Orpington | 2024 |
| Alexa Building Limited | Edinburgh | 2024 |
| Alexa Construction Ltd | London | 2018 |
| Alexa Developments Ltd | Dartford | 2004 |
| Alexa Interior Solution Ltd | Northampton | 2026 |
| Alexa RAY Trading Limited | Leeds | 2026 |
| Alexadrian Carpenter Ltd | London | 2017 |
| Alexan Engineering Services Limited | Huddersfield | 2018 |
| ALEXAN7 Ltd | Edgware | 2025 |
| Alexander & Barclay Ltd | Gerrards Cross | 2019 |
| Alexander & Co Plastering Ltd | Bolton | 2018 |
| Alexander & Co Scotland Limited | Perth | 2005 |
| Alexander & Elai Ltd | Dunstable | 2022 |
| Alexander & Millar Architects Ltd | Ipswich | 2020 |
| Alexander & Moise Group Ltd | Hemel Hempstead | 2017 |
| Alexander & Murray Joiners Limited | Renfrewshire | 2004 |
| Alexander & Young Plastering Ltd | Brechin | 2023 |
| Alexander (Design and Build) Limited | London | 1990 |
| Alexander (Project Management) Limited | Bedfordshire | 2001 |
| Alexander AC Limited | Ascot | 2009 |
| Alexander Akrill Services Limited | Lincoln | 2017 |
| Alexander Alderton Limited | Worcester | 1973 |
| Alexander and Ellis Limited | Plymouth | 2017 |
| Alexander and SON Electrical Services Ltd | Nottingham | 2025 |
| Alexander Anderson Scotland Ltd | Clydebank | 2018 |
| Alexander Anson Ltd | Liverpool | 2018 |
| Alexander Asset Investments Ltd | Leicester | 2015 |
| Alexander Austin James Limited | London | 2018 |
| Alexander Bathrooms Limited | Guildford | 2018 |
| Alexander Baxter Construction Limited | Brighton | 2025 |
| Alexander Beck Ltd | Potters Bar | 2020 |
| Alexander Bespoke Plumbing Services Ltd | Wirral | 2020 |
| Alexander Blacker Management Ltd | Rochester | 2018 |
| Alexander Bonar & Co. Limited | Ballymena | 1976 |
| Alexander Bradshaw Ltd | Milton Keynes | 2021 |
| Alexander Brooke Ltd | London | 2019 |
| Alexander Brown Plumbing Fittings Specialists Ltd | | 1979 |
| Alexander Bruce Estates Limited | Chester | 2005 |
| Alexander Build Ltd | Penryn | 2012 |
| Alexander Builders (UK) Ltd | Colchester | 2002 |
| Alexander Builders Suffolk Ltd | Ipswich | 2021 |
| Alexander Building and Consulting Ltd | Wellingborough | 2014 |
| Alexander Building Services Limited | Glasgow | 2018 |
| Alexander Buildings Ltd | Birmingham | 2018 |
| Alexander Cairnduff & Sons Limited | Newtownards | 1966 |
| Alexander Charles Exquisite Bathrooms Ltd | East Grinstead | 2022 |
| Alexander Charles Limited | St. Albans | 2019 |
| Alexander Chase Capital Ltd | Glasgow | 2020 |
| Alexander Chisholm Construction Limited | Fareham | 2024 |
| Alexander Clare Electrical Services Limited | London | 2017 |
| Alexander Construct Limited | Ilford | 2015 |
| Alexander Construction (East Anglia) Ltd | Ashwellthorpe | 2023 |
| Alexander Construction (Oxfordshire) Limited | Banbury | 2012 |
| Alexander Construction Leicester Ltd | Leicester | 2019 |
| Alexander Construction Ltd. | Chesham | 1992 |
| Alexander Construction Manchester Ltd | Cardiff | 2019 |
| Alexander Construction Services Ltd | Haywards Heath | 2017 |
| Alexander Constructors Ltd | Penarth | 2023 |
| Alexander Contracts Ltd | Belfast | 2016 |
| Alexander Crown Limited | Cardiff | 2017 |
| Alexander Dale Building & Surveying Services Ltd. | Leeds | 1995 |
| Alexander David Electrical Ltd | Tonbridge | 2024 |
| Alexander David Scully Electrics Ltd | Larkhall | 2026 |
| Alexander Decor Ltd | London | 2020 |
| Alexander Decorators Limited | Dundee | 2012 |