| A-2-Z Property Maintenance Ltd | Uxbridge | 2019 |
| A-A Sparks Ltd | Harlow | 2026 |
| A-A-T Plumbing Heating Ltd | Northampton | 2019 |
| A-B-D-S 02 Ltd | London | 2021 |
| A-B-L/Up Limited | Coventry | 2025 |
| A-Bal Developers Limited | South Harrow | 2022 |
| A-Ben Renewables Ltd | Penmaenmawr | 2026 |
| A-Boss Scaffolding Ltd | Portsmouth | 2015 |
| A-C Faur Ltd | London | 2023 |
| A-Cars Travel Ltd | Thruxton | 2012 |
| A-Class Carpentry Limited | Borehamwood | 2009 |
| A-Class Glass and Joinery Ltd | Dundee | 2019 |
| A-Class Heating Services Ltd | London | 2025 |
| A-Class Roofing and Construction Ltd | Salisbury | 2015 |
| A-Consult Limited | Retford | 2004 |
| A-Core Construction Ltd | Nottingham | 2025 |
| A-Core Site Services Ltd | Nottingham | 2025 |
| A-Craft Scaffolding Limited | Worksop | 2022 |
| A-D-C Fabrication Ltd | Great Yarmouth | 2023 |
| A-Dem Demolition Ltd | Watford | 2021 |
| A-Dem Ltd | Limehouse | 2018 |
| A-Demand Electrical Solutions Ltd. | Dartford | 2024 |
| A-Drain Service UK Ltd | Aldermaston | 2008 |
| A-Drill.Uk Limited | Bristol | 2013 |
| A-E Projects Ltd | West Malling | 2026 |
| A-Fix Scaffolding Services Ltd | Aylesbury | 2011 |
| A-Fix Scotland Ltd. | West Lothian | 2003 |
| A-Form Construction Ltd | London | 2015 |
| A-G Plumbing & Houses Ltd | Sunderland | 2021 |
| A-Game Roofing Specialist Ltd | Salisbury | 2026 |
| A-Gas&Electrical Services Ltd | Rowley Regis | 2019 |
| A-Golden Key Construction Ltd | London | 2023 |
| A-Grade Interiors (UK) Ltd | Nottingham | 2023 |
| A-Grade Roofing & Leadwork Limited | Sidcup | 2026 |
| A-Group Highland Ltd | Inverness | 2023 |
| A-J Building Group Ltd | London | 2016 |
| A-K Heating Services Ltd | Burton On Trent | 2017 |
| A-K-E Construction Ltd | London | 2014 |
| A-Kay Electrics Ltd | Maidstone | 2021 |
| A-L-R Installation Group Ltd | Swansea | 2025 |
| A-Lean Ltd | London | 2025 |
| A-Lec Electrical Limited | Tamworth | 2003 |
| A-Lectrical Services Ltd | Birmingham | 2021 |
| A-Lectrical Solutions Ltd | Milton Keynes | 2023 |
| A-Lek Limited | Buntingford | 2005 |
| A-Lift Crane Hire (Holdings) Limited | Wellingborough | 2011 |
| A-Lift Crane Hire Limited | Northampton | 2004 |
| A-Line Building & Carpentry Ltd | Bournemouth | 2024 |
| A-Line Communications Limited | Kidderminster | 2021 |
| A-Line Decorators Limited | Ilford | 2026 |
| A-Line Electrical Ltd | Yelverton | 2015 |
| A-Line Floors Ltd | Middlesbrough | 2026 |
| A-Line Oceana Limited | Ramsgate | 2000 |
| A-List Builders Ltd | Southall | 2014 |
| A-Louis Installations & Joinery Limited | Aberdeen | 2021 |
| A-Mac Environmental Limited | Nairn | 2006 |
| A-Mac Steel Ltd | London | 2014 |
| A-Maisie Build Ltd | Sittingbourne | 2019 |
| A-Maks Construction Ltd | South Ockendon | 2016 |
| A-Malax Ltd | Stanford-Le-Hope | 2026 |
| A-Management Corporate Ltd | Manchester | 2019 |
| A-Mech N.I. Limited | Belfast | 2022 |
| A-Met Engineering Limited | Cookstown | 2011 |
| A-N-R Services Ltd | Waterlooville | 2021 |
| A-Ogun & Sons Limited | Hornchurch | 2025 |
| A-Ogun Limited | Hornchurch | 2007 |
| A-Omega Construction Ltd | Port Glasgow | 2014 |
| A-One (NE) Limited | East Boldon | 2010 |
| A-One Kitchen and Bedroom Fittings Ltd | Hounslow | 2025 |
| A-One Property Care Ltd | Morecambe | 2025 |
| A-Personel Painting Ltd | Sutton-In-Ashfield | 2018 |
| A-Pex Construction (Yorkshire) Ltd | Harrogate | 2024 |
| A-Plan Electrical Limited | Exeter | 2012 |
| A-Plast Ltd | Cannock | 2020 |
| A-Plus Contractors Limited | Ilford | 2019 |
| A-Plus Electrical Systems Limited | Winchester | 2017 |
| A-Plus Electrics (South East) Limited | South Croydon | 2025 |
| A-Plus Renovations Ltd. | Kingston Upon Thames | 2021 |
| A-Ply Carpentry & Building Limited | Newport | 2008 |
| A-R-D Roofing and Cladding Ltd | Ellesmere Port | 2025 |
| A-Rail Limited | London | 2018 |
| A-Reyal Construction Ltd | Hayes | 2022 |
| A-Rock Construction Ltd. | Chesterfield | 2011 |
| A-S Building Services 1 Ltd | Windsor | 2014 |
| A-S Building Services 2 Ltd | Reading | 2018 |
| A-Smart Process Ltd | Slough | 2022 |
| A-Source Plumbing Ltd | Brentwood | 2011 |
| A-Span Limited | Northampton | 1996 |
| A-Spec Carpentry Ltd | Hove | 2008 |
| A-Spec Electrical Ltd | Merthyr Tydfil | 2019 |
| A-Spec Fencing Ltd | Goole | 2017 |
| A-Spec Flooring Ltd | Cheadle | 2026 |
| A-Sprayer Limited | Newark | 2015 |
| A-Sqrd Enterprise Ltd | Oldbury | 2025 |
| A-Squared Real Estate Limited | Coventry | 2019 |
| A-Star Brickwork Ltd | Londonderry | 2024 |
| A-Star Carpentry & Joinery Ltd | Belfast | 2023 |
| A-Star Fire Sprinklers Ltd | Harlow | 2022 |
| A-Star Flooring Services Limited | Northants | 2024 |
| A-Star Home Services Limited | Ipswich | 2018 |