| Moore Stephens CIS Holdings Limited | Professional & scientific | 2002 |
| Moore Stephens CIS Limited | Professional & scientific | 2000 |
| Moorgate Lithoplates Services Limited | Manufacturing | 1981 |
| MORE2COME Limited | Real estate | 2024 |
| Morgan Bates Carpentry Ltd | Manufacturing | 2021 |
| Morgan Bates Ltd | Construction | 2026 |
| Morgan Brookes Ltd | Real estate | 2015 |
| Morgan Cosmetic Surgery Limited | Health & social care | 2022 |
| Morning Property Developments Limited | Construction | 2025 |
| Morrell Consultancy Group Limited | Professional & scientific | 2026 |
| Morrison Couriers Ltd | Transport & logistics | 2019 |
| Mosh ABZ Limited | Wholesale & retail | 2014 |
| Motorshow Events Ltd | Administrative & support | 2017 |
| Motowns Bar Limited | Hospitality | 2025 |
| Mould Prevention Ltd | Construction | 2023 |
| Moulting Muttz Ltd | Other services | 2019 |
| Mount Zion Laboratory Ltd | Manufacturing | 2024 |
| Move Collective Limited | Arts & recreation | 2023 |
| Movement Matters Physio Limited | Health & social care | 2017 |
| Moving Stills Productions Ltd | Professional & scientific | 2015 |
| MPE Estate Ltd | Real estate | 2025 |
| MR Window Limited | Construction | 2000 |
| MR. Magus Ltd | Administrative & support | 2008 |
| MR. Tech Ltd | Wholesale & retail | 2020 |
| MRP Group Ltd | Construction | 2017 |
| MRS C Financial Services Ltd | Financial services | 2025 |
| MRT Enterprises Ltd | Administrative & support | 2021 |
| MSB Benfleet Ltd | Professional & scientific | 2017 |
| MSJ Security Ltd | Administrative & support | 2019 |
| Msmzp Properties Limited | Real estate | 2026 |
| MSN Ventures Group Limited | Real estate | 2018 |
| MTE Offices & Warehousing Ltd | Hospitality | 2026 |
| MTR SQ Construction Ltd | Construction | 2021 |
| Mucmata Limited | Hospitality | 2023 |
| Muddy Mildred's Ltd | Professional & scientific | 2015 |
| Mullins Services Ltd | Professional & scientific | 2024 |
| Mumbleco Ltd | Wholesale & retail | 2024 |
| Mumtaz Catering Limited | Hospitality | 2012 |
| Munal Limited | Information & communication | 2022 |
| Munster Property Limited | Real estate | 2021 |
| Mutts Nutts Productions Limited | Information & communication | 2017 |
| Mvbj Limited | Professional & scientific | 2025 |
| MW Marine & Offshore Ltd | Agriculture & fishing | 2008 |
| MW1 Electrical Ltd | Construction | 2018 |
| My Elements Limited | Administrative & support | 2007 |
| My Global Health Ltd | Health & social care | 2019 |
| My Universal Health Ltd | Health & social care | 2023 |
| Mybeans Limited | Transport & logistics | 2000 |
| Mylex Group Ltd | Construction | 2025 |
| MZP Consultancy Limited | Information & communication | 2019 |
| N B H Services Limited | Construction | 2015 |
| N Hawes Plumbing & Heating Limited | Construction | 2007 |
| N J B Contracts Limited | Construction | 2005 |
| N J S Construction (Essex) Limited | Construction | 2019 |
| N K Heating & Plumbing Ltd | Construction | 2016 |
| N7OVS Property Ltd | Real estate | 2025 |
| Nadia LEE Cohen Ltd | Professional & scientific | 2016 |
| Nagle Property Ltd | Real estate | 2020 |
| Nan's Priority Limited | Administrative & support | 2016 |
| Naomi Banjo Limited | Professional & scientific | 2020 |
| Naserian Consulting Ltd | Health & social care | 2025 |
| Nastec Fire Limited | Construction | 2018 |
| Nathan J Ramsay Limited | Professional & scientific | 2022 |
| Natural Bake (Essex) Ltd | Hospitality | 2017 |
| Natural Bake Leigh Ltd | Hospitality | 2017 |
| Natural Options Limited | Wholesale & retail | 2004 |
| Navigator Baitboats UK Limited | Manufacturing | 2026 |
| NAZ Roofing Ltd | Construction | 2022 |
| NDH Projects Limited | Wholesale & retail | 2023 |
| NDI Mmadu Ltd | Manufacturing | 2020 |
| Neil Mockford Photography Limited | Professional & scientific | 2026 |
| Neliana Limited | Real estate | 2021 |
| Nendle Manufacturing Limited | Other services | 1990 |
| Neofit Interiors Limited | Wholesale & retail | 2018 |
| Nereus Ltd | Professional & scientific | 2025 |
| Nerry Ltd | Transport & logistics | 2021 |
| Nest Plastics Limited | Manufacturing | 2011 |
| Nettra Limited | Health & social care | 2007 |
| New Century Windows Essex Limited | Manufacturing | 2000 |
| New Image (Benfleet) Limited | Construction | 2025 |
| New Image Home Improvements (Essex) Limited | Construction | 2014 |
| New Waverley Studios Limited | Information & communication | 2021 |
| Newberry Management Company Limited | Households | 2013 |
| Newfern Developments Limited | Construction | 2021 |
| Newtown House Ltd | Real estate | 2018 |
| Nexa Recruit Ltd | Administrative & support | 2024 |
| Nexform AM Ltd | Professional & scientific | 2026 |
| Nexgen Dance Ltd | Other services | 2018 |
| Next Level Commercial Cleaning Services Ltd | Extraterritorial | 2020 |
| Next Level Commercial Ltd | Extraterritorial | 2022 |
| Next Level Commercial Services Ltd | Administrative & support | 2019 |
| Next Level Waste Ltd | Extraterritorial | 2022 |
| Next Strides Ltd | Health & social care | 2022 |
| NFC Contractors Ltd | Administrative & support | 2026 |
| NFL Law Limited | Professional & scientific | 2016 |
| NGA Properties Ltd | Real estate | 2021 |
| Ngl's Finest Fish & Chips Ltd | Hospitality | 2022 |
| NH Management Systems Ltd | Real estate | 2008 |
| Nicholls Hayter Limited | Professional & scientific | 2015 |
| Nick Pilton Ltd | Arts & recreation | 2026 |