| MK1 Rail Services Ltd | London | 2025 |
| MKD Pigs Ltd | Norwich | 2018 |
| Mkht Dairy Farms Limited | London | 2025 |
| MKK Fishing Ltd | Banff | 2023 |
| MKM Agriculture Ltd | St. Albans | 2014 |
| Mkme Partners Ltd | London | 2025 |
| MKO Advanced Ltd | Hawick | 2023 |
| MKR Investments Group Ltd | Leicester | 2025 |
| MKS Studio Limited | London | 2020 |
| MKT Bygmester Limited | Somerset | 2007 |
| ML & N Stott Contracting Limited | Wells | 2018 |
| ML Forestry Ltd | Leominster | 2014 |
| ML Racing Bloodstock Ltd | Nuneaton | 2022 |
| MLA Pets Ltd | Birmingham | 2018 |
| MLC Tech Ltd | Berkeley | 2026 |
| MLF Cages Ltd | Sunderland | 2024 |
| Mltt Polo Limited | Tetbury | 2017 |
| MM Agri Ltd | Coleraine | 2024 |
| MM Cleary Holdings Limited | Harrow | 2024 |
| MM Enviro Limited | Worthing | 1993 |
| MM Events Managements Limited | Margate | 2025 |
| MM Fencing Ltd. | | 2005 |
| MM Sellers Limited | Driffield | 2004 |
| MM Tree Services Ltd | Verwood | 2025 |
| MMC Contracting Ltd | Aberdeen | 2024 |
| Mmcalern Limited | Castlewellan | 2026 |
| MMD Corporate Ltd | Tetbury | 2026 |
| MMH Treecare Ltd | London | 2021 |
| MMM Bloodstock Ltd | High Peak | 2026 |
| MMT Services Limited | Chippenham | 1986 |
| MN Jones Digger Services Ltd | St. Ives | 2021 |
| MNC Dog Consultancy Ltd | Spalding | 2021 |
| MNC Partners Ltd | Peterborough | 2026 |
| Mnlv Ltd | Cwmbran | 2016 |
| Mnwfa Property Limited | Inverness-Shire | 1965 |
| MOA Horsemanship Ltd | West Malling | 2024 |
| Moaning Kennels Limited | Uxbridge | 2021 |
| Moat Agriculture & Transport Ltd | Stansted | 2026 |
| Moat Farm (Aldridge) Limited | Polesworth | 2025 |
| Moat Farm Equestrian Centre Limited | Kirkby-In-Furness | 2008 |
| Moat Farm Horticulture Limited | Lincs. | 1992 |
| Moat Hall Farms Limited | Woodbridge | 2013 |
| Moat Yard Limited | Eye | 2025 |
| Moatlands Farm Limited | Tunbridge Wells | 1977 |
| Moats Way Equestrian Ltd | Cambridge | 2006 |
| Mobberley Station Cattery Ltd | Knutsford | 2023 |
| Mobile Farrier Services Limited | Chippenham | 2013 |
| Mobile Orchards Ltd | Rosyth | 2015 |
| Mobile Seeds (Borders) Limited | Shifnal | 1969 |
| Mobile Sheep DIP Limited | Southam | 2024 |
| Mobile Sheep Services Limited | Narberth | 2016 |
| MOD Showjumpers Limited | Basingstoke | 2026 |
| Modaim Limited | Jesmond | 1989 |
| Model Nutrition Dairy Consulting Ltd | Dereham | 2010 |
| Modern Barn Farm Ltd | Battle | 2017 |
| Modern Ecommerce Ltd | London | 2025 |
| Modern Plant Nursery Limited | Beaconsfield | 2014 |
| Modley Limited | Isle Of Skye | 2019 |
| Moel Geifr CYF | Porthmadog | 2016 |
| Moes Group Limited | Stonehouse | 2018 |
| Moes Mowing Limited | Stonehouse | 2024 |
| Mogg Farming Limited | Much Wenlock | 2009 |
| Mohabib Ltd | London | 2025 |
| Mohan Eggs Limited | Newtownbutler | 2015 |
| Mohr View Fishing Ltd | Banff | 2026 |
| Moidart Capital Limited | Edinburgh | 2008 |
| Moigne Combe Bloodstock Ltd | Walton-On-Thames | 2021 |
| Moigne Combe Estate Limited | Walton-On-Thames | 2019 |
| Mojinsuper Ltd | Cardiff | 2021 |
| Mojirayo Ltd | Leicester | 2023 |
| Mojo & Mojo Limited | King'S Lynn | 2021 |
| Mojo Farming Ltd | Peterhead | 2026 |
| Mojo Mushrooms Ltd | Darlington | 2026 |
| Mojo's Dog Boarding and Day Care Ltd | Brisol | 2026 |
| Mole END Farms Limited | Kent | 1993 |
| Mole Management Ltd | Bolton | 2017 |
| Moles Farm Stables Ltd | Buntingford | 2026 |
| Molescroft Farms Limited | Beverley | 1965 |
| Molesfarm Community Projects | Beverley | 2011 |
| Mollie Jayne Fishing Limited | Torquay | 2021 |
| Molly Selby Eventing Ltd | Hexham | 2025 |
| Molly's K9 Pals Ltd | Waterlooville | 2021 |
| Moloney Sporthorses Ltd | Abingdon | 2024 |
| Moltus Investments Limited | Sittinbgourne | 1987 |
| Momentworth Ltd | Barnsley | 2025 |
| MON & Brec Tree Services Ltd | Abergavenny | 2025 |
| MON Mariculture Limited | Bangor | 2012 |
| MON Shellfish Limited | Bangor | 2015 |
| Monachty Estate Ltd | Llanon | 2019 |
| Monarb Limited | Colchester | 2018 |
| Monarch Agricultural Investments Ltd | Bedford | 2021 |
| Monarch Engineering Solutions Limited | Inverurie | 2007 |
| Monarch Farms Limited | Holmfirth | 2003 |
| Monastery Lakes Farm Limited | Towcester | 2026 |
| Monaughty Bloodstock Limited | Bury St. Edmunds | 2015 |
| Monaughty Farms Limited | Peterborough | 1996 |
| Monclone Farm Ltd | Portadown | 2025 |
| Moncreiffe Agricultural Enterprises Limited | | 2003 |
| Mondial Equine and Stud Management Limited | Berwick Upon Tweed | 2013 |
| Mondo Conservation Ltd | Bracknell | 2021 |