| Arctic Building Communities CIC | Walsall | 2024 |
| ARD Local Ltd | Billericay | 2007 |
| ARD Plant Hire Ltd | Bury St. Edmunds | 2025 |
| ARD Recycling Ltd | Bury St. Edmunds | 2021 |
| Ardbrecknish Water Limited | Dalmally | 2024 |
| Ardoch & Co Ltd | Bristol | 2014 |
| Ardomestic and Commercial Ltd | Rochester | 2026 |
| Ardomestic and Commerical Clearances Ltd | London | 2026 |
| Ardudwy Drainage Ltd | Llanbedr | 2024 |
| Areera Ltd | Halifax | 2020 |
| Areera Recycling Holdings Ltd | Elland | 2026 |
| ARG (East Anglia) Limited | Beccles | 2022 |
| ARG Enterprises Ltd. | Oban | 2005 |
| Argall Metal Recycling Limited | London | 2009 |
| Argus Environmental Limited | Helsby | 1992 |
| Argyll Energy Solutions Ltd | Motherwell | 2012 |
| Argyll Resources Limited | Estate, Oban | 2007 |
| ARH Water Treatment Limited | Farnham | 2018 |
| ARI Global Technologies UK Ltd | Brentwood | 2021 |
| Aridam Ltd | Buntingford | 2025 |
| Aries Export Ltd | Oldham | 2025 |
| ARJ Biosustainable Solutions UK Ltd | Birchington | 2024 |
| ARJ Northwest Ltd | Liverpool | 2025 |
| ARK Environmental Services Limited | Walsall | 2009 |
| ARK Waste Solutions Ltd | Radstock | 2019 |
| ARK Water Ltd | Maze | 2024 |
| Arkholme Water Processing Limited | Carnforth | 2010 |
| Arko Group Ltd | London | 2021 |
| ARL Banton Ltd. | Crawley | 2024 |
| ARL Construction Development & Property Maintenance Ltd | London | 2018 |
| Arlo Drainage Ltd | Leeds | 2026 |
| ARM Grab Hire Ltd | Keighley | 2014 |
| Arma Enviro Ltd | Loughgilly | 2024 |
| Armagh Banbridge Craigavon Skip Hire Ltd | Portadown | 2015 |
| Armagh Car Breakers Ltd | Armagh | 2014 |
| ARMCO-BARRIERS4U Ltd | Stoke-On-Trent | 2018 |
| Armitage Mitchell & Sons Ltd | Leicester | 2018 |
| Armo Skip Hire Limited | Chopwell | 2010 |
| Arms Environmental Ltd | Amlwch | 2025 |
| Armstrong Drainage & Plumbing Ltd | Sevenoaks | 2021 |
| Armstrong Gardens & Landscapes Ltd | Edinburgh | 2019 |
| Armstrong Renewables (Scotland) Limited | Dumfries | 2017 |
| Armstrong Waste Management Limited | Dumfries | 1988 |
| Armstrongs Effluent Disposal Limited | Newcastle Upon Tyne | 2002 |
| Armthorpe Skip Hire Ltd | Doncaster | 2025 |
| Armthorpe Skips Ltd | Doncaster | 2011 |
| Arne Water Company Limited | Wareham | 1987 |
| Arno Removals Limited | Welling | 2025 |
| Arnold Waste Disposal Limited | Doncaster | 1968 |
| Arnull Waste Management Ltd | Leicester | 2024 |
| Aroc Waste Management Ltd | Newport | 2022 |
| Aroma Hygiene Limited | Belfast | 2006 |
| ARP Sliding Doors Limited | Andoversford Cheltenham | 2007 |
| Arrora Ltd | Newton Abbot | 2023 |
| Arrow Barns (Eardisland) Plant Company | Herefordshire | 1994 |
| Arrow Environmental Services Limited | Wolverhampton | 1986 |
| Arrow Metals (Redditch) Limited | Worcs | 1987 |
| Arrow Waste Limited | Hastings | 2018 |
| Arrowstar Services Herts Limited | Waltham Abbey | 2011 |
| Art Logistics Limited | Oldbury | 2026 |
| Art Salvage Ltd | Derry | 2019 |
| Arteks Investment Group Limited | London | 2019 |
| Artemes Waste Solutions Ltd. | Stourbridge | 2013 |
| Artemis Environmental Solutions Limited | Exeter | 2009 |
| Artemis House Ltd | Hartlepool | 2026 |
| Arthur Brook (Dewsbury) Limited | Norwich | 1957 |
| Arthur Brook Limited | Dewsbury | 2013 |
| Arthur Brotherton Ltd | West Yorkshire | 2005 |
| Arthur Tech and System Management Ltd | Newark On Trent | 2024 |
| Arthurs Aggregates Limited | Sheffield | 2018 |
| Arthurs Metal Recycling Limited | Sheffield | 2018 |
| Arthurs Skips Limited | Sheffield | 2001 |
| Arthurs Waste Management Limited | Sheffield | 2011 |
| Artichaulage Ltd | Birmingham | 2024 |
| Artisan Water Treatment Limited | Worcester | 2005 |
| Artisanhousekeeping Limited | London | 2024 |
| Arto House Ltd | Falkirk | 2026 |
| Arun Recycling Ltd | Chichester | 2008 |
| Arun Waste Services Limited | Brighton | 2008 |
| AS Environmental Limited | Basildon | 2026 |
| AS Oils Ltd | Glasgow | 2012 |
| AS Waste Solutions Limited | Sutton Coldfield | 2022 |
| Asap Drainage & SON Ltd | Dagenham | 2024 |
| Asap Drainage Limited | Dorchester | 2020 |
| Asap Property Clearances Ltd | Radlett | 2020 |
| Asap Recycling Limited | Preston | 2017 |
| Asarf Limited | Walsall | 2014 |
| Asas for International Trading Ltd | Manchester | 2025 |
| ASB Waste Limited | Wolverhampton | 2016 |
| Asbesafe Environmental Limited | Lincoln | 2016 |
| Asbesafe Limited | Lincoln | 2018 |
| Asbest Behandling Danmark Ltd | London | 2026 |
| Asbest Limited | Consett | 2023 |
| Asbestech Limited | Hatfield | 1997 |
| Asbestos Abatement UK Ltd | Sheffield | 2019 |
| Asbestos and Air Management Services Ltd. | Kendal | 1996 |
| Asbestos Associated UK Ltd | Runcorn | 2012 |
| Asbestos Aware UK Ltd | Bexhill-On-Sea | 2025 |
| Asbestos Away Ltd | Ash Vale Aldershot | 2026 |
| Asbestos Away OK Ltd | Woking | 2020 |