| Maven & I Limited | Wholesale & retail | 2014 |
| MAY Flooring Limited | Administrative & support | 2010 |
| MCB Project Services Limited | Construction | 2013 |
| Meadowview Court M.C. Limited | Administrative & support | 2008 |
| Meadview (Developments) Limited | Real estate | 1994 |
| Meathead Pizza Limited | Hospitality | 2024 |
| Medmix UK Ltd | Manufacturing | 1997 |
| Mera Consultancy & Designs Ltd | Manufacturing | 2017 |
| Metalfx-Liquidmetal-Paint Ltd | Manufacturing | 2025 |
| Metali Window Service Limited | Construction | 2005 |
| Metall-Fx Products Ltd | Manufacturing | 2007 |
| Metin Barber Limited | Other services | 2022 |
| MH Inkpen Consultancy Limited | Professional & scientific | 2018 |
| Michael Blanshard Racing Limited | Arts & recreation | 1999 |
| Mick Fitzgerald Limited | Information & communication | 2004 |
| Millfield Solutions Limited | Information & communication | 2013 |
| Mills Tours Limited | Administrative & support | 2022 |
| Milne-White Books Limited | Wholesale & retail | 2006 |
| Minmarat Ltd | Professional & scientific | 2013 |
| Mint Dental Laboratory Limited | Health & social care | 2011 |
| Mint R&D & Cloud Consulting Ltd | Information & communication | 2020 |
| MIO Fiore Cafe Ltd | Hospitality | 2022 |
| Miokuru Ltd | Hospitality | 2025 |
| Missa Patrem Limited | Construction | 2025 |
| Missing Link Consulting Ltd | Professional & scientific | 2024 |
| Mitchy Motors Lambourn Ltd | Wholesale & retail | 2025 |
| MJ Berry Consulting Ltd | Professional & scientific | 2022 |
| Mltek Limited | Information & communication | 2016 |
| MM Sailplanes Limited | Manufacturing | 2022 |
| Mobilis Consulting Limited | Information & communication | 2001 |
| Modcom Networks Limited | Information & communication | 2022 |
| Montague Park NO.2 (Buckhurst Farm) Management Company Limited | Households | 2018 |
| Montagues Hair Design Limited | Other services | 2004 |
| Monty Accounting Solutions Ltd | Professional & scientific | 2019 |
| Moonlight Tandoori (Hungerford) Ltd | Hospitality | 2026 |
| Morgan & Mills Limited | Construction | 2002 |
| Morgans Yard Limited | Construction | 2020 |
| Moss Vehicle Maintenance Limited | Wholesale & retail | 2024 |
| Motorsport Safety Solutions Ltd | Other services | 2007 |
| Mrqual Limited | Professional & scientific | 1998 |
| MRW Consulting Ltd | Information & communication | 2012 |
| Muddy Mojo Limited | Real estate | 2024 |
| Mumbles 1 Limited | Real estate | 2020 |
| Mumbles 3 Limited | Real estate | 2020 |
| Mumbles 4 Limited | Real estate | 2020 |
| Mumbles 5 Limited | Real estate | 2020 |
| Mumbles 6 Limited | Real estate | 2020 |
| Mumbles 7 Limited | Real estate | 2021 |
| Mumbles Convenience Stores Limited | Financial services | 2021 |
| Mumbles LC 1 Limited | Construction | 2021 |
| Mumbles LC 2 Limited | Construction | 2021 |
| Mumbles Local Centres Limited | Financial services | 2021 |
| Mumbles Petrol & Convenience Holdings Limited | Financial services | 2021 |
| Mumbles Petrol Filling Stations Limited | Financial services | 2021 |
| Munro & Gibson Limited | Real estate | 2023 |
| Munro Properties Limited | Real estate | 1955 |
| MW Associates (Shrewsbury) Limited | Professional & scientific | 2021 |
| MW Bloodstock Limited | Agriculture & fishing | 2024 |
| My Apple Juice Limited | Manufacturing | 2016 |
| My Bathrooms Design Ltd | Wholesale & retail | 2019 |
| My Gold Key Limited | Real estate | 2022 |
| Myriad Bloodstock & Communications Limited | Agriculture & fishing | 1999 |
| MZK Cars Ltd | Wholesale & retail | 2024 |
| N + 1 Cooling Limited | Construction | 2017 |
| N D Services Lambourn Limited | Wholesale & retail | 2003 |
| N. & a. Walker Limited | Agriculture & fishing | 1981 |
| Name Switch Limited | Information & communication | 2015 |
| Nameswitch Deed Poll Services Ltd | Other services | 2020 |
| Nash & Beck Limited | Manufacturing | 2022 |
| Nash Contract Services Limited | Administrative & support | 2001 |
| NAT20 Design Ltd | Information & communication | 2023 |
| Nathan Collings Limited | Agriculture & fishing | 2022 |
| Naturally Fake Limited | Other services | 2016 |
| Naturally Trees Ltd | Agriculture & fishing | 2019 |
| Natures Bakehouse Limited | Manufacturing | 2009 |
| Neilson Advisors Limited | Real estate | 2026 |
| Nelly Holdings Ltd | Financial services | 2021 |
| Netmetrix Limited | Professional & scientific | 2025 |
| Networked Systems Deployment Ltd | Information & communication | 2023 |
| Neurofutures CIC | Education | 2026 |
| Newbury Crossfit and Performance Centre Limited | Arts & recreation | 2017 |
| Newbury Executive Cars Limited | Transport & logistics | 2023 |
| Newbury Plumbing & Heating Limited | Construction | 2025 |
| Newbury Racecourse Management Limited | Households | 2012 |
| Newtons (Hungerford) Limited | Real estate | 1963 |
| Newtons Mews Residents Limited | Households | 2021 |
| Nextphase 3D Designs Ltd | Manufacturing | 2025 |
| Nightjar Shoreditch Limited | Hospitality | 2025 |
| Nines Property Ltd | Construction | 2018 |
| Nivard Ltd | Hospitality | 2018 |
| NLS Property Holdings Limited | Real estate | 2023 |
| Nmpearson Ltd | Professional & scientific | 2024 |
| Nodule Ltd | Real estate | 2023 |
| Norbury Sansom Limited | Professional & scientific | 2016 |
| North Star Tailoring Limited | Wholesale & retail | 2026 |
| Novis Consulting Limited | Professional & scientific | 2016 |
| NPJ Construction Ltd | Professional & scientific | 2013 |
| NRA Developments Ltd | Real estate | 2003 |
| NRG PUB Company Limited | Hospitality | 2024 |
| Nusa Technologies Limited | Information & communication | 2024 |