| Alexander Design Build Ltd | Barry | 2012 |
| Alexander Developing Limited | Leicester | 2011 |
| Alexander Developments Limited | London | 1985 |
| Alexander Drylining Limited | Billericay | 2012 |
| Alexander Duthie & Sons Limited | Aberdeenshire | 1988 |
| Alexander Electrical Ltd | Whitstable | 2003 |
| Alexander Electrical Services Limited | Barnet | 2006 |
| Alexander Elliot Developments Ltd | Plymouth | 2019 |
| Alexander Enabling Ltd | Rugby | 2023 |
| Alexander Environmental Systems Ltd | Herne Bay | 2004 |
| Alexander Flooring Contractors Ltd | Dawlish | 2019 |
| Alexander Fraser Developments Limited | Surrey | 1963 |
| Alexander Fraser Electrical Services Ltd. | Drymen | 2003 |
| Alexander GAS Heating Ltd | Glasgow | 2011 |
| Alexander GAS Servicing Limited | Strathclyde | 2007 |
| Alexander Gatey & Co Limited | Blantyre | 1980 |
| Alexander Grace Bathroom Designs Ltd | Conwy | 2021 |
| Alexander Grey Ltd | Derby | 2023 |
| Alexander Hamel Limited | St Leonards-On-Sea | 2004 |
| Alexander Heating & Plumbing Limited | Bristol | 2024 |
| Alexander Heating Installations Ltd | Barnsley | 2025 |
| Alexander Henry Limited | London | 2012 |
| Alexander Heron Group Limited | London | 2016 |
| Alexander Hodgin Joinery Limited | Cheshire | 2005 |
| Alexander Holdings Limited | Leyland | 2022 |
| Alexander Home FIX Ltd | Brighton | 2024 |
| Alexander Home Improvements (Worcester) Ltd | Worcester | 2025 |
| Alexander Home Improvements Limited | Harlow | 2016 |
| Alexander Homes (Scotland) Ltd | Glasgow | 2016 |
| Alexander Homes (UK) Limited | Tamworth | 2003 |
| Alexander Homes and Developments Limited | Bristol | 2017 |
| Alexander Hopkins Architectural Services Ltd | Drayton Parslow | 2014 |
| Alexander Innovations Limited | Stockport | 2018 |
| Alexander Interiors (Midlands) Ltd | Hinckley | 2025 |
| Alexander J Ross Limited | Ross-Shire | 2005 |
| Alexander Jackman Holdings Limited | Rochester | 2022 |
| Alexander James Carpentry & Building Limited | Ipswich | 2021 |
| Alexander James Contracts Limited | Uxbridge | 2012 |
| Alexander James COX Limited | Exeter | 2002 |
| Alexander James Developments Limited | Colchester | 2024 |
| Alexander James Electrical Services Ltd | Middlesbrough | 2025 |
| Alexander James Facades Limited | Uxbridge | 2022 |
| Alexander James Hodgkinson Contracting Limited | Derby | 2019 |
| Alexander James Kitchens Limited | Stockport | 2024 |
| Alexander James Plumbing and Heating Limited | Barton-Upon-Humber | 2023 |
| Alexander James Projects Limited | Weybridge | 2017 |
| Alexander James Site Engineering Ltd | Preston | 2021 |
| Alexander James Utilities Limited | Uxbridge | 2024 |
| Alexander James Wooden Floors Ltd | Coulsdon | 2021 |
| Alexander Johnson Limited | Uxbridge | 2011 |
| Alexander Johnston & Sons Ltd | South Croydon | 2009 |
| Alexander Johnston Bespoke Cabinetry Ltd | Ivybridge | 2026 |
| Alexander Joinery Ltd | Burnley | 2019 |
| Alexander Knight Property Limited | Waltham Cross | 2015 |
| Alexander Knightford Limited | London | 2019 |
| Alexander Law (Slaters) Limited | Aberdeen | 1999 |
| Alexander Lawrence Limited | Wickford | 2024 |
| Alexander Lawrence Property Limited | Poole | 2018 |
| Alexander Leonard Limited | Paisley | 1973 |
| Alexander Lloyd Construction Ltd | Broadstairs | 2023 |
| Alexander Logan Limited | Glasgow | 2022 |
| Alexander Luxury (Yorkshire) Limited | Hull | 2022 |
| Alexander Luxury Living & Dining Ltd | Plymouth | 2025 |
| Alexander Mackenzie Developments Limited | Southampton | 2017 |
| Alexander Maltby Construction Ltd | London | 2014 |
| Alexander Maltby Limited | | 1995 |
| Alexander Marco Ltd | Addlestone | 2026 |
| Alexander Mason Ltd | Stafford | 2008 |
| Alexander Matthews Stays Ltd | Morecambe | 2023 |
| Alexander Mcfarlane & Company Limited | Glasgow | 1995 |
| Alexander Mills Civils Ltd | Co Tyrone | 2019 |
| Alexander Morrison Limited | Edinburgh | 1963 |
| Alexander Murray Developments Limited | London | 2008 |
| Alexander Newton Developments Limited | Southam | 2022 |
| Alexander NKI Ltd | Edinburgh | 2025 |
| Alexander North West Limited | London | 2013 |
| Alexander Oastler (1946) Limited | Dundee | 1946 |
| Alexander Paterson Limited | London | 2023 |
| Alexander Pearce & SON (Plant) Limited | Weybridge | 1965 |
| Alexander Pearce Limited | Weybridge | 1960 |
| Alexander Pearson Ltd | London | 2024 |
| Alexander Perkins Limited | Swindon | 2014 |
| Alexander Plant & Lifting Limited | Lodon | 2016 |
| Alexander Plastering Limited | Dartford | 2003 |
| Alexander Plumbing and Heating (Beds) Limited | Leighton Buzzard | 2021 |
| Alexander Plumbing and Heating Ltd | Belfast | 2016 |
| Alexander Plumbing Limited | Addlestone | 2008 |
| Alexander Pringle Engineering Solutions Limited | Glasgow | 2017 |
| Alexander Project Services Ltd | Godalming | 2025 |
| Alexander Projects Limited | Barnsley | 2016 |
| Alexander Properties (London) Limited | Surrey | 1997 |
| Alexander Properties Essex & London Limited | Dunmow | 2023 |
| Alexander Properties Ipswich and London Limited | Epping | 2019 |
| Alexander Properties Ipswich Limited | Epping | 2015 |
| Alexander Property Limited | | 2004 |
| Alexander Property Solutions Ltd | Manchester | 2022 |
| Alexander Ramsay Group Ltd | Edinburgh | 2024 |
| Alexander Rankin & SON Limited | Belfast | 1974 |
| Alexander Renovations (Kent) Ltd | Tunbridge Wells | 2023 |
| Alexander Ritchie Plumbers Ltd. | Dundee | 2019 |