| Merthyr Waste Services Ltd | Merthyr Tydfil | 2022 |
| MES Environmental Limited | Grove Park | 1993 |
| Mesh Waste Services Limited | Mildenhall | 2024 |
| MET 1 Trading Limited | Rotherham | 2022 |
| Met-Sort (Recycling) Limited | Walsall | 2008 |
| Meta Future Green (Dorset) Limited | London | 2024 |
| Meta Future Green Limited | Cardiff | 2024 |
| Metal & Stone (Cleaning & Property Maintenance Services) Limited | Kingswood | 1997 |
| Metal & Waste Recycling Limited | Radlett | 2021 |
| Metal and Waste Ltd | Basildon | 2021 |
| Metal Collection & Roof Cleaning Ltd | Birmingham | 2025 |
| Metal Genesis Ltd | London | 2025 |
| Metal MAN Ltd | Crawley | 2026 |
| Metal Recovery Solutions Limited | Waterlooville | 2016 |
| Metal Recycling Limited | Eastbourne | 1997 |
| Metal Scrap Ltd | London | 2023 |
| Metal Solutions (Doncaster) Limited | Barnsley | 2025 |
| Metalco SPS Limited | Peterborough | 2006 |
| Metalcor Recycling Ltd | Callington | 2025 |
| Metalian Ltd | Mexborough | 2024 |
| Metalica Trading Limited | Kenton | 1997 |
| Metalikerr Limited | Birtley | 2014 |
| Metalimpex (U.K.) Limited | London | 1981 |
| Metalink Ltd | Bolton | 2021 |
| Metalite Water Hygiene Limited | Southend-On-Sea | 2025 |
| Metallcom Ltd | Kirkcaldy | 2026 |
| Metalux Trading Limited | Birmingham | 2022 |
| Metcat Ltd | Brierley Hill | 2012 |
| Metcollect Limited | Lisburn | 2015 |
| Metcor Group Ltd | Gravesend | 1989 |
| Metdem Limited | Pontyclun | 2022 |
| Metdem Recycling Limited | Pontyclun | 2023 |
| Meteor Online Limited | Co Tyrone | 2001 |
| Methane Exchange Limited | Bath | 2015 |
| Meticulous Upkeep Services Ltd | London | 2026 |
| Metlab Industrial Limited | Nottingham | 2016 |
| Metro Alloys & Residues Limited | Halesowen | 1985 |
| Metro Construction Limited | Cardiff | 2013 |
| Metro Link Couriers Ltd | Horley | 2025 |
| Metro Metals (Burnley) Limited | Poulton-Le-Fylde | 1985 |
| Metro Waste (London) Limited | Barnet | 2004 |
| Metronis Ltd | Birmingham | 2023 |
| Metropolitan Damp Solutions Ltd | London | 2026 |
| Metz Corporation Ltd | London | 2018 |
| MEZ Waste Management Limited | Pinner | 2020 |
| MF Waste Limited | Sutton | 2024 |
| MF Waste Services Ltd | Sunderland | 2025 |
| MFC Skips Limited | Caterham | 2021 |
| MG Drainage Limited | Watford | 2000 |
| MG OIL Waste Ltd | Liverpool | 2022 |
| MG Skip Hire & Recycling Limited | Bourne | 2009 |
| MG Waste Management Ltd | Manchester | 2009 |
| MGH Waste Ltd | Rochdale | 2025 |
| MGL Facilities Ltd | London | 2019 |
| MGM General Services Limited | Bristol | 2007 |
| MGM Utility Broker Ltd | Ellon | 2026 |
| MGV Auto Spares Limited | Castleford | 2013 |
| MH Roofing Ltd | Blackburn | 2024 |
| MH Services Bristol Ltd | Bristol | 2023 |
| MH Skips Limited | Bath | 2019 |
| MHF Realisations Limited | Derbyshire | 1984 |
| Mhonz Empire Ltd | Manchester | 2023 |
| MHZ Scrap Metal Ltd | Bradford | 2025 |
| MI Jetting and Drainage Limited | Robertsbridge | 2021 |
| MIA OIL Collection Ltd | London | 2022 |
| MIA Waste Management Limited | Tamworth | 2022 |
| MIA Waste OIL Ltd | Mexborough | 2018 |
| Mialgae Ltd | Edinburgh | 2016 |
| Micaman Services Ltd | Waltham Cross | 2020 |
| Michael's Waste Removals Ltd | Leeds | 2022 |
| Mick Denton Metal Recycling & Skip Hire Limited | Cambridge, | 2000 |
| Mick George Earthworks Limited | Maidenhead | 2015 |
| Mick George Environmental Limited | Maidenhead | 2016 |
| Mick George Recycling Limited | Maidenhead | 2017 |
| Mick the Skip Limited | Solihull | 2014 |
| Mick's Tidy UP Ltd | Cardiff | 2016 |
| Micncstarsuk Ltd | Liverpool | 2019 |
| Micro Tool Hire Limited | Radstock | 2021 |
| Microstation Ltd | Leatherhead | 2011 |
| Microvi UK Limited | London | 2018 |
| MID Kent Breakers Limited | Oxted | 2008 |
| MID Kent Metals Recycling Limited | Oxted | 2002 |
| MID Surrey Community Fridges CIC | Dorking | 2019 |
| Mid-Sussex Wood Recycling Project Limited | Brighton | 2006 |
| Midas Upholstery Limited | Newcastle Upon Tyne | 1973 |
| Midas Waste Management Limited | Maidstone | 2018 |
| Middlesex County Recycling Ltd | London | 2016 |
| Middlesex Fast Recycling Limited | London | 2021 |
| Middlesex Reclaim & Waste Collection Limited | Twickenham | 2017 |
| Middlesex Recycling Limited | Ashford | 2014 |
| Middlesex Waste Management Limited | Ashford | 2017 |
| Middleton Waste Services Ltd | Ipswich | 2018 |
| Middletown Metals Ltd | Middletown | 2017 |
| Midgeham Cliff END Quarry Limited | Crosshills | 2003 |
| Midiskips.Co Ltd | London | 2026 |
| Midland Autobreakers Smethwick Limited | Kidderminster | 2014 |
| Midland Car Breakers Ltd | Wolverhampton | 2011 |
| Midland Chemicals Waste Management Limited | West Midlands | 1987 |
| Midland Construction U.K. Ltd | Birmingham | 2022 |
| Midland Cylinder Recycling Ltd | Sutton Coldfield | 2022 |