| Markimeld LtdUnited Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1978 |
| Marks and Spencer P.L.C.London, United Kingdom · UKmarksandspencer.com · checked 28 Oct 2026 | UK | 0 | – | – | –Mid (producers) | – | 1926 |
| Marlico LimitedTorquay, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2003 |
| Marlin Equity Partners LtdLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2012 |
| Marlo Enterprises LimitedShrewsbury, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2021 |
| Maroush Food Production LtdLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2011 |
| Marriott Webb LtdCardiff, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2023 |
| Marshdry Serv LtdManchester, United Kingdom · UKchecked 26 Oct 2026 | UK | 0 | – | – | – | – | – |
| Marston's PLCWolverhampton, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1890 |
| Marta Vine LimitedWalsingham, United Kingdom · UKmartavine.co.uk · checked 28 Oct 2026 | UK | 0 | – | – | – | – | 2010 |
| Marta's Vinyard LtdBexley, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2000 |
| Marussia Beverages UK LimitedLondon, United Kingdom · UKmarussiabeverages.com · checked 28 Oct 2026 | UK | 0 | – | – | –Mid (producers) | – | 1988 |
| Maschio Gaspardo UK LimitedLincoln, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2018 |
| Mason and Mason Wines LimitedLondon, United Kingdom · UKchecked 26 Oct 2026 | UK | 0 | – | – | – | – | – |
| Massey Bros LtdCrewe, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1957 |
| Mathies Trading LtdBrockenhurst, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2017 |
| Matteo Lupi Wines LtdGreenwich, United Kingdom · UKmatteolupiwines.com · checked 28 Oct 2026 | UK | 0 | – | – | – | – | 2017 |
| Matthew Clark Bibendum LimitedBristol, United Kingdom · UKmcbdrinks.co.uk · checked 28 Oct 2026 | UK | 0 | – | – | –Mid (producers) | 8% | 2007 |
| Matthew Jukes Productions LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1998 |
| Mavega UK LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2013 |
| Maxy Cash & Carry LimitedEnfield, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2016 |
| Maybourne Hotels LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1998 |
| Mayfair Delivers LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2008 |
| Mayfair Hg LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2022 |
| Mccann Manchester LimitedMacclesfield Cheshire, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1986 |
| Mccloskey International LtdBirmingham, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1988 |
| Mccormac Vintners LimitedMuch Wenlock, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2022 |
| Mckenzie Fine Wines LtdGodalming, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2007 |
| Mckinley Vintners LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2010 |
| Mclaren Racing LimitedWoking, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1980 |
| Mcmillan Motorsport LimitedBurton on Trent, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2012 |
| Mcqueens Flowers LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2017 |
| Mde Services Group LimitedBracknell, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2016 |
| Mdeliverygroup LtdLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2018 |
| Mdrc Deli LimitedSouthampton, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2022 |
| Me Group International PLCEpsom, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1962 |
| Meadow Foods LtdChester, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1992 |
| Mechanised Project ManagementLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1946 |
| Mecm, LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 1996 |
| Medagio LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2016 |
| Mediterranean Direct LtdBlackburn, United Kingdom · UKmediterraneandirect.co.uk · checked 28 Oct 2026 | UK | 0 | – | – | – | – | 2007 |
| Mellasat Wines LimitedNorwich, United Kingdom · UKchecked 26 Oct 2026 | UK | 0 | – | – | – | – | – |
| Memento Exclusives LimitedNorthampton, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2010 |
| Mengia e Bevi Vino Torino LimitedHarrogate, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2023 |
| Mentzendorff & Co LtdLondon, United Kingdom · UKmentzendorff.co.uk · checked 28 Oct 2026 | UK | 0 | – | – | –Premium (producers) | 20% | 1968 |
| Mephisto Wine Merchants LtdLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2007 |
| Mercanti Imports LimitedBristol, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2016 |
| Mercato Italiano LimitedBridport, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2014 |
| Mercia Wines LtdCoventry, United Kingdom · UKchecked 28 Oct 2026 | UK | 0 | – | – | – | – | 2020 |
| Messrs Allen Overy Shearman Sterling LLPLondon, United Kingdom · UKchecked 26 Oct 2026 | UK | 0 | – | – | – | – | – |