| M W H Estates Ltd | Sheffield | 2022 |
| M W Jetting Ltd | Birmingham | 2021 |
| M W Sweepers Limited | Rochester | 2009 |
| M Waste Removals Ltd | Liverpool | 2025 |
| M Way Group Limited | Hoddesdon | 2021 |
| M White (Skips) Limited | Sheffield | 2013 |
| M Wyatt Agricultural Contractors Limited | Wimborne | 2002 |
| M&A Hamilton Consultancy Ltd | Lincoln | 2023 |
| M&E Metal Solutions Ltd | Waterlooville | 2025 |
| M&G Strip OUT Ltd | Worcester Park | 2019 |
| M&H Holdings Group Limited | Chelmsford | 2023 |
| M&J ALL Trades Limited | Hull | 2024 |
| M&J Asbestos Specialists Ltd | Melksham | 2025 |
| M&J Rubbish Ltd | Glasgow | 2025 |
| M&J Waste Management Ltd | South Molton | 2021 |
| M&L Waste Management Ltd | London | 2025 |
| M&M OIL Collection Limited | London | 2021 |
| M&M Waste Plymouth Ltd | Launceston | 2024 |
| M&R Skip Hire Limited | Dartford | 2018 |
| M. & M. Skip Hire Limited | Oxfordshire | 1992 |
| M. G. Building Services Limited | Bromborough | 2003 |
| M. Gaze & Co. Limited | Norwich | 1969 |
| M.A.N Shelters Limited | Chesterfield | 2003 |
| M.A.W. Shredding Services Limited | St Helens | 2011 |
| M.B UK Solutions Limited | Salford | 2024 |
| M.B.C. Civil Engineering Ltd | Ludgershall | 2019 |
| M.B.C. Signs (London) Limited | London | 1992 |
| M.B.H. Builders Limited | Wolverhampton | 2004 |
| M.C. Northern Limited | Derbyshire | 2000 |
| M.D.J. Light Brothers (Scrap Processers) Limited | Hailsham | 1971 |
| M.E. Waste Services Limited | Cheltenham | 2018 |
| M.G.S. Trading Ltd | London | 2011 |
| M.N Recycling Solutions Limited | Chesterfield | 2016 |
| M.R. Drains Ltd | Windlesham | 2011 |
| M.S. and S. Graver Ltd | Norwich | 2006 |
| M.W. Waste Drainage Support Services Limited | Richmond | 2011 |
| M.W. White Limited | Norwich | 2010 |
| M14 Innovations Limited | Cardiff | 2024 |
| M2 Recycling Ltd | Newtownabbey | 2024 |
| M3 Contracts Falkirk Ltd | Glasgow | 2022 |
| M34 Removals and Maintenance Services Ltd | Manchester | 2023 |
| M3RVEILLE UK Limited | London | 2025 |
| M6 Waste Ltd | Ashton-Under-Lyne | 2023 |
| M60 Skip Hire Limited | Bury | 2010 |
| M@V Removals OR Waste Specialists Ltd | Ellesmere Port | 2025 |
| MA Grab Hire Limited | Rossendale | 2015 |
| MA Merchants Ltd | Worthing | 2025 |
| Ma&T Limited | Paisley | 2020 |
| Maanjoes Movers Co Ltd | Stoke-On-Trent | 2024 |
| MAB Removal Services Ltd | Barnsley | 2018 |
| MAC Recycling Limited | Walsall | 2009 |
| MAC Skip Hire Limited | Walsall | 2015 |
| MAC Skips Limited | Walsall | 2016 |
| MAC Waste Management UK Limited | Walsall | 2015 |
| Macc Scrap Metals Ltd | Macclesfield | 2020 |
| Macdonald Group Limited | Dunfermline | 2022 |
| Mace Auctions Limited | Lancaster | 2025 |
| Macem Group of Companies Ltd | Maidstone | 2025 |
| Mach Resources UK Ltd | Warrington | 2023 |
| Machinery Breakers NI Ltd | Ballynahinch | 2025 |
| Mackers Total Recycling Ltd | Leigh-On-Sea | 2010 |
| Mackey Demolition Limited | Bridgend | 2015 |
| Mackey Demolition Services Limited | Ascot | 1972 |
| Mackey Group Holdings Ltd | Bridgend | 2025 |
| Mackhouse Landfill Solutions Ltd | Fakenham | 2017 |
| Maclin Environmental Services Ltd | Little Hadham | 2019 |
| Macnabb Bros (Waste Management) Ltd | Country Down | 1993 |
| Mactra Marine Limited | Weston-Super-Mare | 2014 |
| Macwaste Ltd | Warrenpoint | 1992 |
| Macwater Ltd | Inverurie | 2018 |
| MAD Movers Coventry Ltd | Coventry | 2026 |
| MAD4 Commercial FM Maintenance & Service Compliance Company Ltd | London | 2025 |
| Madd Recovery Limited | Coatbridge | 2021 |
| Maddison Squared Gardens & Waste Services Ltd | Pontypridd | 2021 |
| Maen Karne Aggregates Limited | Newquay | 2005 |
| MAG Aggregates Ltd | London | 2024 |
| MAG Environmental Limited | Sheffield | 2021 |
| Magbag Industries Ltd | Pontefract | 2024 |
| Magdalena & Guney Ltd | London | 2023 |
| Magenko Limited | | 1993 |
| Magfern Mini-Waste Limited | Derby | 1987 |
| Magfern Recycling (2018) Ltd | Derby | 2018 |
| Magic P Waste Collection Ltd | Billingshurst | 2024 |
| Magla Limited | Staplefield | 2024 |
| Magman Inspection Ltd | Burnley | 2012 |
| Magre Enterprise Limited | Blyth | 2021 |
| Maia Waste Ltd | Wakefield | 2021 |
| Maidenhatch Estate Limited | Reading | 1989 |
| Maidenhead Skip Hire Ltd | Maidenhead | 2017 |
| Main Trade Services Cleaning Ltd | Witney | 2021 |
| Main's Lettings Limited | Launceston | 2021 |
| Main's Motors Limited | Ewelme | 1957 |
| Mainline Drain Cleaning (UK) Ltd | Preston | 2012 |
| Mainline Environmental Installations Ltd | Derby | 2004 |
| Mainline Recycling Ltd | Derby | 2019 |
| Mainline Salvage & Recovery Ltd | Wolverhampton | 2016 |
| Mainline Sewer Services Limited | Worthing | 2023 |
| Mains to Drains Limited | Marsh Barton | 2024 |
| Mainstream Water Services Ltd | Thornton-Cleveleys | 2018 |
| Mainswell Ltd | Whitchurch | 2024 |