| Midland Drain Solutions Limited | Stourbridge | 2019 |
| Midland Drainage Limited | Brierley Hill | 2005 |
| Midland Land Reclamation Limited | Maidenhead | 1983 |
| Midland Metals Recycling Limited | Loughborough | 2005 |
| Midland OIL Recycling Ltd | Ruislip | 2020 |
| Midland Plastic Recycling Limited | Chaddesley Corbett | 2017 |
| Midland Rock Recycling Limited | Leicester | 2018 |
| Midland Skip Hire Limited | London | 2004 |
| Midland Toilet Hire Limited | Jewellery Quarter | 2013 |
| Midland Truck Breakers Ltd | Melton Mowbray | 2010 |
| Midland Tyre Control Limited | Bilston | 2002 |
| Midland's Probate Clearance Ltd | Walsall | 2026 |
| Midlands Adoption Services Ltd | Birmingham | 2025 |
| Midlands Biohazard Trauma Specialist Cleaning Limited | Kidderminster | 2025 |
| Midlands Disposal Skip Hire Limited | Walsall | 2026 |
| Midlands Green&Clean Ltd | Leicester | 2025 |
| Midlands Legionella Control Limited | Burntwood | 2014 |
| Midlands Reclamation and Waste Limited | Warwick | 2002 |
| Midlands Recycle Limited | Stafford | 2025 |
| Midlands Recycling Solutions Ltd | Mansfield | 2024 |
| Midlands RS Ltd | Mansfield | 2024 |
| Midlands Sewer Maintenance Limited | Evesham | 2015 |
| Midlands Street & Ground Works Ltd | Bilston | 2021 |
| Midlands Urban Recycling Ltd | West Bromwich | 2016 |
| Midlands Waste Limited | Birmingham | 2019 |
| Midlands Waste Management Limited | Leamington Spa | 2019 |
| Midlands Waste Solutions Ltd | Birmingham | 2024 |
| Midlothian Advice & Resource Centre | Midlothian | 2004 |
| Midlothian Skip Hire Ltd | Loanhead | 2011 |
| Mids Services Ltd | Long Bennington | 2020 |
| Midwest Resources Solutions Limited | Harrow | 2022 |
| Mighty Pest Control Limited | London | 2015 |
| Migo Group Ltd | London | 2023 |
| Migo Ltd | London | 2023 |
| Migrama Plastics Limited | Smethwick | 2011 |
| Mike Toon Limited | Bournemouth | 2009 |
| Mikes Maindrain Ltd | Rochester | 2014 |
| Mil-Tek (Scotland) Limited | East Kilbride | 1999 |
| Milber Salvage & Spares Limited | Newton Abbot | 2003 |
| Mildenhall Skip Hire Limited | Bury St. Edmunds | 2015 |
| Milestone Environmental Limited | Wallingford | 2015 |
| Milk in a Box Ltd | Liverpool | 2019 |
| Mill Farm Recycling Limited | Stafford | 2024 |
| Mill House Metals Ltd | Liverpool | 2012 |
| Millbarn Outfall Limited | Preston | 2023 |
| Millenium Industrial Cleaning Limited | Coventry | 2014 |
| Millennium Hygiene Services Limited | Preston | 2007 |
| Millennium Just Parts Ltd | Pontefract | 2022 |
| Miller & Cain Holdings Limited | Winchester | 2019 |
| Miller Martin Waste Services Ltd | Peterborough | 2023 |
| Millstone Mechanical Services Limited | Slough | 1986 |
| Millthorpe Fields Management Company Limited | Sleaford | 2000 |
| Milltol Limited | Rotherham | 1989 |
| Milrec UK Limited | Aberdeen | 2004 |
| Milton Keynes Water Softeners Ltd | Buckinghamshire | 2000 |
| Milton Town Treatment Works Limited | Holsworthy | 2004 |
| Mimet Ltd | Doncaster | 2015 |
| Mims Wholesale Ltd | Batley | 2024 |
| Minaera Limited | St. Albans | 2010 |
| Mineral Asbestos Ltd | Glasgow | 2026 |
| Mini Shred Ltd | Chorley | 2019 |
| Mini Skip Hire Ltd | London | 2023 |
| Mini Waste Limited | Sudbury | 2015 |
| Miniskips Ltd | Leek | 2018 |
| Mint & Lite Ltd | London | 2025 |
| Mint Hygiene Ltd | Kingston Upon Thames | 2013 |
| Mintworth Transport Limited | Worcester | 1989 |
| Miracle 1 Services Ltd | Gloucester | 2025 |
| Mircea Limited | London | 2017 |
| Miricharis Ltd | Ilford | 2017 |
| Miscellanea Movers Ltd | Nottingham | 2025 |
| Miss Catch’Em Pest Control Ltd | Orpington | 2022 |
| Mister Miffy Ltd | Swansea | 2025 |
| Mister Shifter Services Ltd | Newcastle Under Lyme | 2025 |
| Mister Water Softener Ltd | Hemel Hempstead | 2024 |
| Mitch Bird-Jones Contracting Limited | Wrexham | 2025 |
| Mitchell & Mayle Ltd | Ely | 2013 |
| Mitchell Drainage and Environmental Solutions Ltd | Centrum 100 | 1998 |
| Mitchell Industrial Services Limited | St. Helens | 2002 |
| Mitchell Thomson Limited | Glasgow | 1951 |
| Mitchellson Aggregates and Recycling Limited | Slough | 2001 |
| Mitie Waste & Environmental Services Limited | London | 2013 |
| Mitre and George Consultants Ltd. | London | 2015 |
| Mitros Cash for Clothes Ltd | Port Talbot | 2015 |
| Miwaste Ltd | Chichester | 2025 |
| Mixit Aggregates Ltd | London | 2015 |
| MJ Aggregates and Waste Ltd | New Cross Gate | 2024 |
| MJ Developments (Leeds) Ltd | Dewsbury | 2015 |
| MJ Developments (Parsons House) Limited | Dewsbury | 2020 |
| MJ Filtration Limited | Harlinton | 2025 |
| MJ Metal and Waste Limited | Gateshead | 2024 |
| MJ Recycling Limited | Milford Haven | 2017 |
| MJ Rubbish Ltd | Harrow | 2025 |
| MJ Rubbish Removals Ltd | Newport | 2013 |
| MJ Vehicle Recovery Service Limited | Doncaster | 2025 |
| MJA Drainage Solutions Ltd | Wigan | 2014 |
| Mjag Ltd | Leeds | 2017 |
| MJL Services Ltd. | Wallsend | 2015 |
| MJM Haulage Ltd | Glasgow | 2020 |
| MJM Skip Hire Limited | York | 2026 |