| Marine Networks Ltd | Information & communication | 2026 |
| Mario Barba Ltd | Administrative & support | 2014 |
| Mark O'Kane 3D Limited | Wholesale & retail | 2009 |
| Mark Whenham Limited | Professional & scientific | 2008 |
| Marketing and More Ltd | Professional & scientific | 2021 |
| Markopoulos Ltd | Wholesale & retail | 2024 |
| Marston Green Development Company Limited | Construction | 2019 |
| Marton Garage 2016 Limited | Wholesale & retail | 2019 |
| Maryvale Homes Limited | Construction | 2023 |
| Matrix Consulting Services Ltd | Professional & scientific | 2026 |
| Matthew Bunting Antiques Limited | Other services | 2022 |
| Maximum Attack Limited | Information & communication | 2017 |
| Mayora Holdings Ltd | Real estate | 2026 |
| MB Excellence Ltd | Administrative & support | 2022 |
| Mbmbs Limited | Financial services | 1997 |
| MCG Environmental Engineering Ltd | Construction | 2020 |
| Mclaughlin Family Office (UK) Ltd | Professional & scientific | 2024 |
| MD Gardner Limited | Professional & scientific | 2010 |
| MDF Profiles Limited | Professional & scientific | 2001 |
| Meadow Studio Ltd | Professional & scientific | 2021 |
| Mediatex Limited | Information & communication | 2008 |
| Medicare Connect Ltd | Wholesale & retail | 2024 |
| Merlin Earth Movers Limited | Water & waste | 2025 |
| Metropolis Property Management Ltd | Real estate | 2020 |
| Mettle & Grace Limited | Other services | 2025 |
| Michael Fairhurst Ltd | Construction | 2019 |
| Microscope Ltd | Professional & scientific | 2018 |
| Midland Scientific Ltd | Manufacturing | 2022 |
| Midlands Property Partners Limited | Real estate | 2024 |
| Mill House Management (Southam) Limited | Households | 2016 |
| Mindsight Psychology Services Ltd | Health & social care | 2024 |
| Minerva JBE Limited | Professional & scientific | 2023 |
| Mini Mega Festivals Limited | Professional & scientific | 2025 |
| Minoan Pictures Limited | Information & communication | 2019 |
| Mira Business Limited | Other services | 2018 |
| MIS Casas EN Alquiler (Residential Lettings) Ltd | Real estate | 2025 |
| Miss Julie ASH Design Ltd | Information & communication | 2022 |
| Mitchard Ltd | Information & communication | 2025 |
| MJ Modifications Limited | Manufacturing | 2023 |
| Mjqs (M&E) Limited | Professional & scientific | 2012 |
| Mmpp Co Limited | Wholesale & retail | 2008 |
| Mmzo FO Limited | Financial services | 2023 |
| Moabi Ltd | Real estate | 2026 |
| Mobile Sheep DIP Limited | Agriculture & fishing | 2024 |
| Monaco Mapwork Ltd | Education | 2025 |
| Montague (Emscote) House Management Company Limited | Households | 2002 |
| Morgan Cyber Solutions Limited | Information & communication | 2023 |
| Moss Gone Ltd | Administrative & support | 2020 |
| Move Over Recruitment UK Limited | Administrative & support | 2012 |
| MR2 Championship Limited | Manufacturing | 2006 |
| MSB Fitters Ltd | Construction | 2024 |
| Mummins Ltd | Hospitality | 2024 |
| Muncila Chiropractic Limited | Health & social care | 2007 |
| Mygreenlipstick Limited | Professional & scientific | 2008 |
| Myring Holdings Limited | Administrative & support | 2023 |
| N J N Management Ltd | Administrative & support | 2009 |
| Napton Cidery Limited | Manufacturing | 2016 |
| Napton Lettings Limited | Real estate | 2017 |
| Napton Lock Brewhouse Limited | Manufacturing | 2024 |
| Napton Marina Limited | Transport & logistics | 1975 |
| Napton Padel (Construction) Ltd | Arts & recreation | 2025 |
| Napton Plant Ltd | Administrative & support | 2025 |
| NDC Advisors Ltd | Extraterritorial | 2012 |
| Nemesia Designs Limited | Professional & scientific | 1999 |
| NET Zero and Energy Frameworks Limited | Professional & scientific | 2026 |
| New Business Department Consultancy Limited | Professional & scientific | 2010 |
| Newfields Fine Homes Limited | Hospitality | 2006 |
| Newstones Property Limited | Real estate | 2003 |
| Newton Poplars Ltd | Real estate | 2020 |
| Nextwave IT Ltd | Information & communication | 2020 |
| Nforcd Ltd | Manufacturing | 2020 |
| Nibbles Moments Ltd | Hospitality | 2025 |
| Nigel Barnett Plumbing and Heating Limited | Construction | 2003 |
| Nightingale Farm Estate Ltd | Agriculture & fishing | 2024 |
| Niko Limited | Manufacturing | 1999 |
| NNR Property Ltd | Real estate | 2022 |
| NO Middle MAN Enterprises Limited | Administrative & support | 2019 |
| Noralle (Holdings) Limited | Professional & scientific | 2014 |
| Noralle Traditional Country Homes Limited | Construction | 2006 |
| Norman Contracts Limited | Construction | 2015 |
| North Farm Holdings Ltd | Agriculture & fishing | 2024 |
| Nova VIA RS Limited | Construction | 2026 |
| NP Plastering Services Limited | Construction | 2020 |
| NSP Properties Limited | Administrative & support | 2007 |
| Nspa Associates Ltd | Financial services | 2023 |
| Nspa Trading Ltd | Wholesale & retail | 2011 |
| Nualaw Limited | Professional & scientific | 2008 |
| Nutriclub Ltd | Education | 2026 |
| NV Consultants Limited | Financial services | 2017 |
| Oak and Key Ltd | Real estate | 2020 |
| Oak Retirement Limited | Real estate | 2012 |
| Oakwood Plumbing & Heating Ltd | Construction | 2024 |
| OAR Estates Limited | Real estate | 2018 |
| Oblong (UK) Limited | Information & communication | 2006 |
| OC Housing Ltd | Real estate | 2021 |
| Old Potash Farm Limited | Agriculture & fishing | 2015 |
| Old Timber Yard Long Itchington Limited | Administrative & support | 2025 |
| Oliver Wealth Ltd | Professional & scientific | 2022 |
| ON the Hill Properties Ltd | Real estate | 2023 |
| Orchard (Engineering) Solution Limited | Administrative & support | 2010 |