| Meowing MAD Cat Rescue Ltd | Redditch | 2026 |
| MER Fishing Ltd | Elgin | 2026 |
| Mercantil International Ltd | London | 2023 |
| Mercaston Willow Limited | Derby | 2020 |
| Mercer Farming Limited | Burton On Trent | 1964 |
| Mercer Major Fauld Ltd | Burton-On-Trent | 2022 |
| Mercer Show Team Ltd | Cambridge | 2025 |
| Merchant Youldon Limited | Holsworthy | 2008 |
| Mercore Services Group Limited | Mansfield | 2015 |
| Mercurial Holdings Ltd | Droitwich | 2021 |
| Mercurial Medical Ltd | London | 2022 |
| Mercury Environmental Systems 1 Ltd | Edinburgh | 2021 |
| Mercury Environmental Systems Ltd | Edinburgh | 2020 |
| Mercury Instruments Limited | St. Ives | 1992 |
| Mercury Pest Control Limited | London | 2017 |
| Merdale Fruits Ltd | Whitstable | 2010 |
| Mere Beck Limited | Blackpool | 2006 |
| Mere Brow Farm Limited | Manchester | 2015 |
| Mere Environmental Limited | Chester | 2021 |
| Mere Farm (Mannington) Limited | Aylsham | 1976 |
| Mere Plantations Limited | Chester | 2007 |
| Mere Tectona Direct Ltd | Chester | 2007 |
| Mere Trout Ltd | Warminster | 2018 |
| Merecourt Farming Ltd | Old Langho | 2021 |
| Meredith Davies Agri Repairs Ltd | Llandeilo | 2004 |
| Meremouth Farm Limited | Peterborough | 2023 |
| Mergold Limited | London | 2017 |
| Meric Fish Limited | Castle Douglas | 2011 |
| Meridian Farms Limited | Whittlesey | 2012 |
| Meridian Kung FU (Benfleet) Limited | Leigh On Sea | 2015 |
| Meritus Resources Ltd | London | 2019 |
| Merkland Farms Ltd. | Castle Douglas | 2016 |
| Merlesque Ltd | Bromsgrove | 2026 |
| Merlin Facilities Limited | Consett | 1993 |
| Merlin Falconry Ltd | Market Rasen | 2015 |
| Merlin Tree Services Limited | Glasgow | 2018 |
| Merlon Limited | Burry Port | 1985 |
| Merlott Chitty Farms Ltd | Market Drayton | 2016 |
| Merrell Performance Horses Ltd | Bradford-On-Avon | 2026 |
| Merrells Growers Ltd | Beccles | 2018 |
| Merrick Contracting Limited | Peterborough | 2020 |
| Merriefield Farms Limited | Rushden | 1978 |
| Merrifield Agriculture Ltd | Crediton | 2014 |
| Merrifield Alpacas Limited | Milton Keynes | 2009 |
| Merrijohn Ltd | Holsworthy | 2005 |
| Merriment Wood Ltd | Durham | 2021 |
| Merris Bros (Farmers) Limited | Rugby | 1954 |
| Merritt Tree Specialists Ltd | Southampton | 2003 |
| Merrivale Energy Limited | Plungar | 2013 |
| Merrivale Farms Limited | Nottingham | 1979 |
| Merry FOX Stud Limited | Knutsford | 2006 |
| Merry Stem Ltd | Walton On Thames | 2010 |
| Merryfield Farmers Limited | Shepton Mallet | 2006 |
| Merryhagen Farming Ltd | Kilmarnock | 2023 |
| Merryhill Mushrooms Limited | Chichester | 2006 |
| Merryvalls Limited | Droitwich | 2013 |
| Merrywood Farm Limited | Ashford | 2012 |
| Mersea Farming Ltd | Liverpool | 2025 |
| Mersea Trawlers Limited | Colchester | 2011 |
| Mersey Forest Foundation | Liverpool | 2014 |
| Mersey Garden Group Community Interest Company | Manchester | 2025 |
| Merslaugh Farm Limited | Stranraer | 2007 |
| Merston Farm Limited | Halnaker,Chichester | 1984 |
| Merthyr Tydfil Angling Alliance | Merthyr Tydfil | 2018 |
| Merthyr Tydfil Angling Association | Merthyr Tydfil | 2004 |
| Merton Dairy Ltd | Cambridge | 2019 |
| Merton Farming Company Limited | Thetford | 1974 |
| Mertoun Estate Farms Limited | Newmarket | 2000 |
| Mervyn Thomas Limited | Hereford | 2002 |
| Mesa Limited | Burscough | 2002 |
| Mescar Fisheries Limited | Liverpool | 2025 |
| Messers a Kirkbride Limited | Carlisle | 2008 |
| Messers Ferguson & Armitage Ltd | Thurso | 2025 |
| Messingham Sands Fishery Ltd | Scunthorpe | 2020 |
| Messrs a & N Batty Limited | Maryport | 2013 |
| Messrs Bland Limited | Cockermouth | 2023 |
| Messrs Butterworth Limited | Appleby In Westmorland | 2016 |
| Messrs C a Weir and SON Limited | Ayr | 2022 |
| Messrs Charles HAY Limited | | 2003 |
| Messrs Cottam Limited | Cumbria | 2006 |
| Messrs Coutts Ltd | Inverurie | 2025 |
| Messrs Davies (Penlan Farm) Ltd. | Llanwrda | 2015 |
| Messrs Ewbank Limited | Cumbria | 2006 |
| Messrs Fettes Ltd | Buckie | 2014 |
| Messrs G & M E Woodhouse & Sons Limited | Lancaster | 2023 |
| Messrs Holliday Limited | Cumbria | 2006 |
| Messrs J & M Anderson Limited | Forfar | 2013 |
| Messrs J Dickinson Farming Company | Wigton | 2012 |
| Messrs J Dixon & Sons Limited | Wigton | 2016 |
| Messrs J G Gardhouse Limited | Carlisle | 2009 |
| Messrs J Rogerson (Alton) Ltd | Dumfries | 2013 |
| Messrs James Kennedy Ltd | Mauchline | 2013 |
| Messrs Jenkinson Limited | Kirkby Stephen | 2010 |
| Messrs John R S Grant Limited | Dundee | 2003 |
| Messrs Kennedy Ltd | East Lothian | 1954 |
| Messrs L Craven Limited | Brigg | 2013 |
| Messrs Owen CYF | Llandysul | 2013 |
| Messrs P and TL Edmondson Limited | Ulverston | 2002 |
| Messrs Peile Limited | Cumbria | 2006 |
| Messrs R Mcneil Ltd | Stranraer | 2017 |