| Millar Farming Limited | Roxburghshire | 2023 |
| Millar Tree Services Limited | Enniskillen | 2025 |
| Millard Poultry Limited | Wells | 2003 |
| Millbank Livery Limited | Ipswich | 2018 |
| Millbank Steading Limited | Lochwinnoch | 2025 |
| Millbeck Forests Limited | Chippenham | 2014 |
| Millbrook Farm Ltd | Martock | 2019 |
| Millbry Hill Stud Limited | Stokesley | 2020 |
| Millbuie Livery Limited | Westhill | 2015 |
| Millburs Stud Ltd | Newport Pagnell | 2020 |
| Millchurch Farms Ltd | Salisbury | 2025 |
| Millchurch Ltd | Salisbury | 2025 |
| Millco Farming Limited | Exeter | 2014 |
| Milldaw Equestrian Ltd | Sutton-In-Ashfield | 2026 |
| Millenheath Farms Limited | Whitchurch | 2015 |
| Millennium (Orkney) Ltd | South Ronaldsay | 2013 |
| Millennium 17 Ltd | Peterhead | 2019 |
| Millennium Crofts Limited | Eastbourne | 2018 |
| Millennium Farming Company Limited | Wisbech | 2024 |
| Millennium Professional Centre (MPC) Ltd | Barking | 2024 |
| Miller and Parker Agriculture Limited | Falmouth | 2023 |
| Miller Farms Limited | Aberdeen | 2021 |
| Miller Farriers Limited | Lincoln | 2018 |
| Miller Fishing Co Ltd | Wick | 2025 |
| Miller Hill Farms Ltd | Millisle | 2022 |
| Miller JAX Ltd | Banff | 2020 |
| Miller Tree Surgery Ltd | Glasgow | 2026 |
| Miller Wheel & Cultivator Co.Limited(The) | Orpington | 1940 |
| Millers Contracting Limited | Wigton | 2002 |
| Millets Farm and Kitchen Ltd | Reigate | 2025 |
| Millfarm NK Limited | Higham Ferrers | 2020 |
| Millfield Farming Limited | Bridlington | 2012 |
| Millfold Forestry Ltd | Pulborough | 2018 |
| Millglen Farms Limited | Alloa | 1980 |
| Millhill Farms Limited | Perthshire | 1997 |
| Millhouse Fertility Clinic Ltd | Gateshead | 2023 |
| Millhouse World of Wood Limited | Sowerby Bridge | 2012 |
| Millie & Belle Ltd | Bristol | 2018 |
| Milliedolls Ltd | Warrington | 2023 |
| Milligan Farms | Portadown | 2024 |
| Milligan-Manby Farms Ltd | Market Rasen | 2014 |
| Milligen Mcleod Contracting Limited | Norwich | 2010 |
| Milling Farms Ltd | Dungannon | 2019 |
| Millington (Farms) Limited | Selby | 1974 |
| Millington (Gallops Farm) Limited | Oakham | 2004 |
| Millington Limousins Limited | Driffield | 2012 |
| Millman Contractors Limited | Holsworthy | 2021 |
| Millmoor Woodland Enterprises Ltd | Crediton | 2018 |
| Millmore Eggs Ltd | Antrim | 2025 |
| Millom and Broughton Agricultural Society Ltd | Broughton-In-Furness | 1995 |
| Millpoint Showdogs Ltd | Heanor | 2020 |
| Millrodgie Limited | Perth | 2022 |
| Mills Agri Services Ltd | Dingwall | 2024 |
| Mills Agricultural Limited | Oakham | 2011 |
| Mills Beech Limited | Salisbury | 2010 |
| Mills Poultry Limited | Welshpool | 2002 |
| Millstone Ornamentals Limited | Montgomery | 1999 |
| Millstream (Yarmouth) Ltd | Yarmouth | 1963 |
| Milltown Farm Limited | | 2007 |
| Millvalefarm Ltd | Belfast | 2021 |
| Millview Dairy Farm Ltd | Newtownards | 2024 |
| Millview Eggs Ltd | Moy | 2018 |
| Millview Nursery Limited | Market Rasen | 2003 |
| Millward Farms Ltd | Whitchurch | 2020 |
| Millwood Market Garden Ltd | Witney | 2016 |
| Millys PAW Care Ltd | Southampton | 2025 |
| Milmac (Dutch Spotted Sheep) Ltd | Derby | 2024 |
| Milmill Ltd | Cardiff | 2018 |
| Milne Agri Limited | Forfar | 2017 |
| Milner Homes Limited | Hebden Bridge | 1980 |
| Milton Enterprises Limited | Taunton | 2003 |
| Milton Field Sports Limited | Wells | 2006 |
| Milton Hall Fields GWT Limited | East Sussex | 2022 |
| Milton Hill Farming Limited | Pewsey | 1998 |
| Milton of Leuchars Limited | St. Andrews | 2014 |
| Milton(Peterborough)Estates Company, | Peterborough | 1934 |
| Miltons Estate Limited | Somerset | 1997 |
| Minch Harvesters Limited | Point | 2026 |
| Mind Forestry Ltd | Dunblane | 2022 |
| Mind Motion Creation Ltd | Hemel Hempstead | 2024 |
| Mind the Trees (Yorkshire) Ltd | Pudsey | 2021 |
| Mind,Body & Spirit Nurturing Ltd | Bishop Auckland | 2024 |
| Mindrum Farming Company Limited | Northumberland | 1971 |
| Minds Alike Animal Training and Behaviour Limited | Aylesbury | 2021 |
| Minecope Limited | Porth | 1988 |
| Minefleet Farms Limited | Poulton Le Fylde | 1949 |
| Minehill Farm Ltd. | Newry | 2016 |
| Mineral Advice Limited | Shrewsbury | 2025 |
| Minett's Farm Ltd | Cheltenham | 2019 |
| Mingke Jewelry Co., Ltd | London | 2018 |
| Mingys Sun Limited | London | 2022 |
| Mini Farms Ltd | Reading | 2011 |
| Mini ME (Yorkshire) Limited | Todmorden | 2019 |
| Mini Meadows Farm Ltd | Welford | 2009 |
| Mini Motley Sanctuary CIC | Woodbridge | 2026 |
| Mini Moxons CIC | Liverpool | 2022 |
| Mini One Plant Hire Limited | Luton | 2004 |
| Miniature Mediterranean Donkey Association | Bamburgh | 2003 |
| Minimal Damage Ltd | St Leonards On Sea | 2012 |
| Minimarket Grocery Ltd | Oldham | 2025 |