| Lockstones Lettings Limited | Real estate | 2014 |
| LON PIN Solar Limited | Professional & scientific | 2019 |
| Long Newnton Solar Limited | Energy | 2012 |
| Louis Harvey Limited | Arts & recreation | 2021 |
| Loveuwedo Ltd | Education | 2024 |
| Lowenna Properties Limited | Real estate | 2021 |
| Lucutus Ltd | Information & communication | 2025 |
| Lucy TOM Interiors Limited | Wholesale & retail | 2012 |
| Luminous Investments Ltd | Real estate | 2024 |
| Lumley Garden and Pet Supplies Ltd | Wholesale & retail | 2026 |
| Luxuryita Limited | Administrative & support | 2025 |
| Lydiard Services Limited | Extraterritorial | 2006 |
| Lyntonfox Limited | Wholesale & retail | 2019 |
| M&C Electricians Ltd | Construction | 2025 |
| M&Korkmaz Ltd | Other services | 2020 |
| M.A.C. Hotels Ltd | Hospitality | 2001 |
| M20 Homes Limited | Real estate | 2013 |
| Macam Ltd | Administrative & support | 2018 |
| Madama Systems Limited | Information & communication | 2015 |
| Madinirisk Limited | Professional & scientific | 2013 |
| Maison LET Limited | Real estate | 2002 |
| Maker Culture Limited | Wholesale & retail | 2022 |
| Mallard Flyfishers Limited | Agriculture & fishing | 2003 |
| Malmesbury (2016) Ltd | Hospitality | 2016 |
| Malmesbury Abbey Books Limited | Wholesale & retail | 1992 |
| Malmesbury Abbey Cafe Limited | Hospitality | 2012 |
| Malmesbury Barbers Limited | Other services | 2026 |
| Malmesbury Bowls and Social Club Ltd | Arts & recreation | 2023 |
| Malmesbury C of E Primary School | Education | 2013 |
| Malmesbury Dental Ltd | Health & social care | 2017 |
| Malmesbury Italian Limited | Hospitality | 2019 |
| Malmesbury Joinery Ltd | Administrative & support | 2016 |
| Malmesbury Live Arts CIC | Arts & recreation | 2020 |
| Malmesbury MCM Limited | Administrative & support | 2015 |
| Malmesbury River Valleys Trust | Education | 1992 |
| Malmesbury Town Team CIC | Administrative & support | 2019 |
| Malmesbury Village Foods Limited | Hospitality | 2017 |
| Maltings Mill Management Company Limited | Households | 1993 |
| Management Services Limited | Real estate | 1960 |
| Manor Farm Wiltshire Ltd | Construction | 2022 |
| Manor West Homes Limited | Construction | 2013 |
| Mark Fletcher Joinery Ltd | Construction | 2014 |
| Marvern House Limited | Construction | 2013 |
| Matthew Rich Roofing Services Limited | Construction | 2025 |
| Maycroft Homes Management Company Limited | Other services | 2015 |
| MDR Pharma Ltd | Professional & scientific | 2009 |
| Meadow View Equine and Locum Services Ltd | Agriculture & fishing | 2019 |
| Mechsign Limited | Professional & scientific | 2008 |
| Medeka Ltd | Professional & scientific | 2010 |
| Meerhay Consulting Limited | Professional & scientific | 2012 |
| Megasteel Ltd | Wholesale & retail | 1991 |
| Megasteel Ropes Limited | Wholesale & retail | 2023 |
| Messer Project Management Ltd | Real estate | 2023 |
| Messer Property Management Ltd | Households | 2023 |
| MFP Music Ltd | Arts & recreation | 2025 |
| MHM Investments Limited | Real estate | 2007 |
| Mica Investments Limited | Real estate | 2024 |
| Michael Norton Water Consultancy Limited | Construction | 2014 |
| Middleton-Taylor Associates Limited | Agriculture & fishing | 2013 |
| Milbo Castle Solutions Limited | Administrative & support | 2025 |
| Millar Beldon Associates Limited | Professional & scientific | 2011 |
| Mindful Wins Ltd | Wholesale & retail | 2025 |
| Mindvision Design Limited | Extraterritorial | 2005 |
| Mindvision Media Limited | Professional & scientific | 2007 |
| Minety Music Festival Limited | Arts & recreation | 2016 |
| Minety Pre-School CIC | Education | 2014 |
| Minety Rugby Football Club Ltd | Arts & recreation | 2014 |
| MJS Tax Advisory Limited | Professional & scientific | 2019 |
| Mneo Properties Limited | Real estate | 2025 |
| Modus Corporate Limited | Construction | 1995 |
| Moffatt Engineering Limited | Water & waste | 2004 |
| Monedero M3 Limited | Wholesale & retail | 2019 |
| Monsaraz Consulting Limited | Professional & scientific | 2013 |
| Mooretechgroup Ltd | Information & communication | 2020 |
| Mostyn Chase Ltd | Administrative & support | 2010 |
| MRB Heating Ltd | Construction | 2023 |
| Mrinsights Limited | Professional & scientific | 2014 |
| Msec Marketing Limited | Professional & scientific | 2012 |
| Mulberry Professional Services Ltd | Administrative & support | 2012 |
| MUM of the Home Ltd | Information & communication | 2018 |
| Murcott Farm Shop Limited | Wholesale & retail | 2024 |
| Mywhitedog Ltd | Education | 2018 |
| N ACH Consulting Limited | Professional & scientific | 2004 |
| N Houghton Ltd | Manufacturing | 2011 |
| Nadarra Aesthetics Limited | Other services | 2025 |
| Nail Supplies Global Limited | Other services | 2021 |
| Nanotech Applications Ltd | Professional & scientific | 2018 |
| Natarix Ltd | Health & social care | 2026 |
| Nathan IND Financial Planning Limited | Professional & scientific | 2023 |
| Naturbeads Ltd | Professional & scientific | 2018 |
| Navigame Ltd | Information & communication | 2024 |
| NC Fasteners Limited | Wholesale & retail | 2013 |
| NC Industries Limited | Wholesale & retail | 2003 |
| Ndnl Consulting Ltd | Information & communication | 2024 |
| New ERA Event Productions Ltd | Arts & recreation | 2022 |
| New Life Church, Cirencester | Education | 2007 |
| Newton Liveries Limited | Agriculture & fishing | 2023 |
| Next Generation Carpentry Limited | Construction | 2022 |
| Nightspark Investments Ltd | Real estate | 2025 |
| Nimble and Wild Ltd | Arts & recreation | 2023 |