| Marris Farming Ltd | Grantham | 2024 |
| Marris Foston Limited | Grantham | 2005 |
| Marrison Agriculture Limited | Norwich | 2005 |
| Marsdens Farms Limited | Sheffield | 2007 |
| Marsh Agricultural Cleaning Services Ltd | Diss | 2019 |
| Marsh and Fallow Ltd | Dartford | 2024 |
| Marsh Court Farm Limited | Gloucester | 1999 |
| Marsh Farm Free Range Limited | Yeovil | 2017 |
| Marsh Farm Ltd | Oldham | 2024 |
| Marsh Game Limited | King'S Lynn | 2016 |
| Marsh Green Estates Ltd | Chesterfield | 2007 |
| Marsh Hall Farms Limited | Hull | 2021 |
| Marsh Hill Farm Limited | Aylesbury | 1973 |
| Marsh House Farming Company | Wigton | 2012 |
| Marsh Leys Limited | Bedford | 1964 |
| Marsh Poultry Ltd | Merseyside | 2011 |
| Marsh Produce Limited | Romney Marsh | 2009 |
| Marsh View Farms Ltd | Preston | 2021 |
| Marshall Agricultural Limited | York | 2019 |
| Marshall Cherries (Scotland) Ltd. | Dunfermline | 2004 |
| Marshall Contracting Group Limited | London | 2016 |
| Marshall Farming Limited | Doncaster | 2004 |
| Marshall Farms (Ashton) Limited | Peterborough | 2015 |
| Marshall Holdings (Southern) Ltd | Golden Cross | 2019 |
| Marshall Plant Hire Limited | Newton Abbot | 2007 |
| Marshall Plant Limited | Birmingham | 2020 |
| Marshalls (Donington) Limited | Spalding | 2002 |
| Marshalls Equine Ltd | Leeds | 2025 |
| Marshalls Farm Limited | Chichester | 2015 |
| Marshalls Fisheries Consultant Ltd | Cambridge | 2017 |
| Marshalls Land Services Ltd | Wilmslow | 2017 |
| Marshalls Tree Surgeons Ltd | Newcastle Upon Tyne | 2011 |
| Marshalvane Limited | Selby | 1980 |
| Marshay Farm Limited | Tiverton | 2020 |
| Marshchapel Carp Fisheries Limited | Grimsby | 2018 |
| Marshfield Botanicals Ltd | Wedmore | 2021 |
| Marshfield Traditional Farm Limited | Chippenham | 2005 |
| Marshgate Irises Ltd | North Walsham | 2013 |
| Marshside Fishing Co. Limited | Southport | 2002 |
| Marshwood Alpacas Ltd | Crewkerne | 2015 |
| Marshwood Farm Limited | Burnham | 2009 |
| Marston Farms Limited | Abergavenny | 1977 |
| Marston Fields Fishery Ltd | Sutton Coldfield | 2022 |
| Marston Forestry Ltd | Haslemere | 2018 |
| Marston Lakes Ltd | York | 2025 |
| Marston Park Estate Limited | Shaftesbury | 2004 |
| Marston Park Farm Limited | Ashbourne | 2016 |
| Marston Vale Farms Limited | Bedford | 2008 |
| Marston Vale Services Trading AS the Forest Centre Limited | Bedford | 1998 |
| Marston Vale Tree Care Ltd | Bedford | 2018 |
| Martha's Blooming Gardens Ltd | Horsham | 2023 |
| Martholme Farm Limited | Blackburn | 1963 |
| Martin & Sons (March) Limited | Wisbech | 1950 |
| Martin Ainscough Farms Limited | Wigan | 1958 |
| Martin and Peter Limited | Beaminster | 2025 |
| Martin Body Limited | Cornwall | 1938 |
| Martin Cardno Ltd | Fraserburgh | 2014 |
| Martin Clifton Limited | Ashford | 1959 |
| Martin Dairy Holdings Limited | Bodmin | 2022 |
| Martin Dairy Limited | Bodmin | 2010 |
| Martin Enterprises Limited | Buckinghamshire | 1981 |
| Martin Evans Contracting Ltd | Oswestry | 2015 |
| Martin Evans Farming Ltd | Oswestry | 2015 |
| Martin Farms Ltd | Newtownards | 2025 |
| Martin Farquhar (Skye) Ltd | Isle Of Skye | 2018 |
| Martin Field Farms Limited | Carlisle | 1989 |
| Martin Hares Agri Services Limited | Wells | 2011 |
| Martin Haskett Agricultural Contractors Ltd | Taunton | 2002 |
| Martin House Farms Limited | Ormskirk | 2019 |
| Martin Mcginn & Sons Ltd | Newry | 2003 |
| Martin MEE Ltd | Uttoxeter | 2013 |
| Martin Oakes T/A Specialist Paddock Maintenance Services Ltd | Tean | 2020 |
| Martin Pears Sporting Limited | Leeds | 2018 |
| Martin Reel Ltd | Newry | 2002 |
| Martin Ritchie Limited | Fraserburgh | 2005 |
| Martin Robey Engineering Limited | Nuneaton | 1982 |
| Martin Whiteley Limited | Wakefield | 2013 |
| Martino Resources Ltd | Littlehampton | 2023 |
| Martins & Childs Services Ltd | Cirencester | 2003 |
| Martins of Rushden Limited | Northamptonshire | 2004 |
| Martins Plants Ltd | Buntingford | 2003 |
| Martleaves Farm and Campsite Limited | Weymouth | 2023 |
| Martlet Corporation, Ltd | London | 2025 |
| Martletwy House Limited | Pembrokeshire | 2018 |
| Martley Hall Stud Limited | Woodbridge | 2020 |
| Martock Farms Limited | Stoke-Sub-Hamdon | 2011 |
| Martom Farms Ltd | Liphook | 2019 |
| Marton Manor Farm Limited | East Yorkshire | 2005 |
| Marty Haulage Ltd | Magherafelt | 2018 |
| Martyn England Construction Limited | Ilminster | 2001 |
| Martyn Richardson Farriers Ltd | Tetbury | 2020 |
| Martyn Thomas & Co. Limited | Cowbridge | 1987 |
| Marutomo Limited | Edinburgh | 2018 |
| Marvgallup Group Ltd | London | 2021 |
| Marwell Horse Transport Limited | Hungerford | 2021 |
| Marwell Thoroughbreds Limited | Hungerford | 2000 |
| Mary Margaret Mackie Trading Limited | Liverpool | 2015 |
| Mary Mccall Smith Limited | Crieff | 2010 |
| Marylands Farm Limited | Lincolnshire | 1985 |
| Maryvale Farms Limited | Banbridge | 2024 |