| Longbourn Finance Ltd | Wholesale & retail | 2014 |
| Lori Sitton Talent Acquisition Ltd | Administrative & support | 2017 |
| Lost Boys Catering Ltd | Hospitality | 2026 |
| Lottie’S Frome Limited | Hospitality | 2017 |
| Loud Mouth Coffee Ltd | Manufacturing | 2018 |
| Lowden Ambrose Ltd | Professional & scientific | 2015 |
| LP Installations and Repairs Ltd | Construction | 2023 |
| LR Property Services Ltd | Construction | 2017 |
| LRC Holdings Ltd | Hospitality | 2019 |
| Luciel Limited | Other services | 2011 |
| Lullington Power Limited | Energy | 2007 |
| Lumber Jack Leisure Limited | Hospitality | 2021 |
| Lungi Babas Ltd | Hospitality | 2019 |
| Luzaac & Co Ltd | Wholesale & retail | 2025 |
| M & J Transport and Sons Ltd | Transport & logistics | 2022 |
| M & S Houses Ltd | Real estate | 2012 |
| M & V Lettings Limited | Real estate | 2010 |
| M a Gunter Grounds Maintenance Ltd | Administrative & support | 2014 |
| M a Hairdressing Limited | Other services | 2024 |
| M a Sanders Properties Limited | Professional & scientific | 2005 |
| M Aesthetics by Emily Roberts Ltd | Other services | 2021 |
| M Civil Engineering Limited | Construction | 2015 |
| M Collister Logistics Ltd | | 2013 |
| M D Day Woodland Contractor Ltd | Agriculture & fishing | 2002 |
| M Hollyoake Consulting Services Limited | Professional & scientific | 2012 |
| M Keeling Farming Ltd | Agriculture & fishing | 2020 |
| M W R Coles Properties Ltd | Real estate | 2020 |
| M.I.Lettings Ltd | Real estate | 2019 |
| M.J.T. Brickwork Ltd | Construction | 2020 |
| MACH6 Publications Ltd | Information & communication | 2021 |
| Maclaines Warehouse Limited | Real estate | 2020 |
| Macomatic Ltd | Information & communication | 2016 |
| Madhatter Commercial Ltd | Professional & scientific | 2022 |
| Magseis FF (UK) Ltd | Financial services | 2017 |
| Mahphotographs Ltd | Professional & scientific | 2025 |
| Major Plumbing Company (Wells) Limited | Construction | 2013 |
| Makers Yard Somerset Ltd | Real estate | 2018 |
| Making Faces Limited | Health & social care | 2017 |
| Malissa Brown Ltd | Arts & recreation | 2012 |
| Maltbarn (Sussex) Ltd | Construction | 2018 |
| Mann F Studio Ltd | Information & communication | 2024 |
| Manor Farm (Skinner's Hill) Management Company Ltd | Households | 2023 |
| Manor Farm Glastonbury Ltd | Hospitality | 2012 |
| MAP S.Solutions Ltd | Construction | 2013 |
| Marant Investments Limited | Real estate | 2017 |
| Marcelle's Tennis Academy Limited | Hospitality | 2024 |
| Marchant & Marchant Limited | Financial services | 2003 |
| Marianne Johnson Psychotherapy Ltd | Health & social care | 2023 |
| Marjoram Media Ltd | Information & communication | 2011 |
| Mark Baker Consulting Limited | Administrative & support | 2006 |
| Mark Bruce Company Limited | Arts & recreation | 2023 |
| Mark Bull Ltd | Administrative & support | 2015 |
| Market Place Barbers Limited | Other services | 2022 |
| Marketing AF Ltd | Administrative & support | 2020 |
| Marksdanes Restorations Limited | Wholesale & retail | 1995 |
| Marley and Jerome Bespoke Limited | Manufacturing | 2024 |
| Marmot Asset Management Limited | Financial services | 2025 |
| Marmot Tours Limited | Administrative & support | 2005 |
| Marsh Farm (East Woodlands) Ltd | Other services | 2020 |
| Marson Dart Holdings Ltd | Professional & scientific | 2024 |
| Marston Foods Limited | Manufacturing | 2010 |
| Marston Gate Properties Limited | Real estate | 1999 |
| Master Fresh (UK) Limited | Hospitality | 2013 |
| Matilda Morrogh-Ryan Limited | Professional & scientific | 2022 |
| Matilda Rose Ltd | Other services | 2025 |
| Maulisha & Co Limited | Wholesale & retail | 2026 |
| Mavire Ltd | Manufacturing | 2024 |
| Mawsonia Holdings Limited | Professional & scientific | 2025 |
| Maximising Velocity Ltd | Real estate | 2015 |
| Maxin Holdings Limited | Real estate | 2024 |
| Maxin Limited | Real estate | 1993 |
| Mayday Saxonvale Development Limited | Construction | 2021 |
| MC Roofing (SW) Ltd | Construction | 2022 |
| Mcandrews Properties Limited | Real estate | 2012 |
| Mcintosh DBR Works Ltd | Construction | 2020 |
| Mcintosh Developments (Camerton) Ltd | Construction | 2021 |
| Mcintosh Developments (Keinton) Ltd | Construction | 2019 |
| Mcintosh Developments East Harptree Ltd | Construction | 2018 |
| Mcintosh Developments KM Ltd | Construction | 2021 |
| Mcintosh Developments Ltd | Construction | 2014 |
| Mcmenemy Automotive Ltd | Wholesale & retail | 2019 |
| Mdbr Ltd | Construction | 2017 |
| MDC Therapy Services Ltd | Health & social care | 2024 |
| Meatmylk Limited | Information & communication | 2023 |
| Mecob Design Ltd | Professional & scientific | 2014 |
| Mells Sports and Recreation Company Limited | Arts & recreation | 2011 |
| Mells Water Recreation Company Limited | Arts & recreation | 2001 |
| Mendip Accountancy Limited | Professional & scientific | 2002 |
| Mendip Accountancy Services Limited | Professional & scientific | 2005 |
| Mendip Developments & Investments Ltd | Real estate | 2017 |
| Mendip Developments Limited | Construction | 2005 |
| Mendip Green Ltd | Real estate | 2025 |
| Mendip Pallets Limited | Manufacturing | 2005 |
| Mendip Renovations Limited | Construction | 2025 |
| Meridian FS Limited | Financial services | 2016 |
| Merlin Theatre Trust Limited | Arts & recreation | 1992 |
| MERLIN360.COM Limited | Information & communication | 2005 |
| MES Amis Food Ltd | Hospitality | 2006 |
| MES Amis Maison Ltd | Professional & scientific | 2017 |
| Meyer Energy Ltd | Professional & scientific | 2025 |