| Mercer Samad Ltd | Real estate | 2021 |
| Merch (Retail) Limited | Wholesale & retail | 2016 |
| Merchants & Sons Limited | Professional & scientific | 2012 |
| Mercurey Amis Limited | Real estate | 2025 |
| Mercury Aviation Ltd | Professional & scientific | 2019 |
| Mercury Motors (King's Lynn) Limited | Wholesale & retail | 2022 |
| Mercy Manas Ltd | Wholesale & retail | 2025 |
| Merge 54 Plus Limited | Professional & scientific | 2025 |
| Mericon-Uk Ltd | Information & communication | 2025 |
| Meridian Analytica Ltd | Information & communication | 2026 |
| Meridian Business and Educational Supplies Limited | Wholesale & retail | 2008 |
| Meridian Computer Systems Limited | Other services | 2008 |
| Meridian Group Ltd | Administrative & support | 2019 |
| Meridian Office Furniture Ltd | Wholesale & retail | 2020 |
| Meridian Park Management Company Limited | Real estate | 2002 |
| Meridon Management Limited | Households | 1994 |
| Merillian Consultancy Ltd | Professional & scientific | 2016 |
| Merino Wool UK Ltd | Wholesale & retail | 2012 |
| Merlin Couriers Ltd | Transport & logistics | 2026 |
| Merlin DMS Limited | Administrative & support | 2017 |
| Merlin Market Ltd | Wholesale & retail | 2022 |
| Merlin Properties (Norwich) Limited | Real estate | 2026 |
| Mermaid Residents Management Company Limited | Households | 2023 |
| Mermaid Tears E Liquids Ltd | Wholesale & retail | 2016 |
| Mermaids Slipper Norfolk Ltd | Hospitality | 2018 |
| Meronmead Limited | Hospitality | 2001 |
| Merrells & Ellis Limited | Construction | 2025 |
| Merrie Gardens Limited | Real estate | 2006 |
| Merry Oak Timberworks Ltd | Construction | 2014 |
| Mesh Property Limited | Real estate | 2019 |
| Meshaistic Ltd | Wholesale & retail | 2023 |
| MET Commercial Services Limited | Professional & scientific | 2018 |
| Metagenomic Solutions Limited | Extraterritorial | 2022 |
| Metagravity Group Limited | Information & communication | 2021 |
| Metalstyle Ltd | Manufacturing | 2019 |
| Metam Technologies UK Limited | Information & communication | 2024 |
| Metcalfe North East Limited | Construction | 2017 |
| Meteor Power Limited | Professional & scientific | 2013 |
| Method Consultancy Group Ltd | Professional & scientific | 2023 |
| Method Marketing Ltd | Professional & scientific | 2020 |
| Meticulis Ltd | Information & communication | 2024 |
| Metis IT Consulting Ltd | Information & communication | 2012 |
| Metro ( Norwich ) Limited | Hospitality | 2026 |
| Metro Properties Mc/R Ltd | Construction | 2016 |
| Metron Designs Limited | Manufacturing | 1990 |
| Mettacare Ltd | Health & social care | 2009 |
| Mettastorage Ltd | Transport & logistics | 2025 |
| Mettserv Limited | Real estate | 2015 |
| Meus Prop Co Limited | Real estate | 2025 |
| MEW Photography Limited | Professional & scientific | 2014 |
| Mews Holiday Properties Limited | Real estate | 2021 |
| Meyer Scott Ltd | Administrative & support | 2024 |
| MF Building Plans and Surveying Ltd | Professional & scientific | 2025 |
| MF Business Holdings Ltd | Financial services | 2021 |
| MF Enterprise Group Limited | Financial services | 2026 |
| MF Motors (Norwich) Ltd | Wholesale & retail | 2025 |
| MF Properties & Investments Limited | Real estate | 2026 |
| MF Transport & Recovery Ltd | Wholesale & retail | 2025 |
| MFB (Blofield) Limited | Households | 2013 |
| MFH Property Ltd | Real estate | 2020 |
| MFK Recruitment Ltd | Administrative & support | 2018 |
| Mfmm Real Estate Limited | Real estate | 2023 |
| Mfpersonalised Ltd | Wholesale & retail | 2025 |
| MG Critten Ltd | Construction | 2015 |
| MG Flooring Contractors Limited | Construction | 2001 |
| MG Hair & Beauty Ltd | Other services | 2010 |
| MG Halejcio Property Ltd | Real estate | 2025 |
| MG Medics Limited | Health & social care | 2012 |
| MG Pipework Limited | Construction | 2013 |
| MG Plumbing & Heating (Norfolk) Ltd | Construction | 2019 |
| MG Regency Suites Ltd | Real estate | 2013 |
| Mgadent Limited | Health & social care | 2022 |
| Mgams Ltd | Administrative & support | 2025 |
| Mgasbarro Ltd | Information & communication | 2022 |
| MGB EMH Ltd | Manufacturing | 2024 |
| MGF Norfolk Ltd | Administrative & support | 2015 |
| Mgps Developments Ltd. | Extraterritorial | 2004 |
| Mgps Hotels Limited | Real estate | 2006 |
| Mgps Property Limited | Real estate | 2006 |
| MGR Home Improvements & Maintenance Ltd | Construction | 2019 |
| MGS Electrical Ltd | Construction | 2018 |
| MGS Safety Management Ltd | Administrative & support | 2023 |
| MH Scientific Limited | Professional & scientific | 2026 |
| Mh(Vw)E Custodian Trustee Company Ltd | Financial services | 2020 |
| MHF Ltd | Administrative & support | 2014 |
| MHG Ltd | Construction | 2017 |
| MHG Project Services Ltd | Professional & scientific | 2015 |
| MHI (Kent) Limited | Construction | 2016 |
| MHI Ltd. | Financial services | 1994 |
| MHJ Riches Ltd | Administrative & support | 2009 |
| MHK Offshore Engineering Limited | Professional & scientific | 2019 |
| MHL Roofing Ltd | Construction | 2024 |
| MI Systems Ltd | Information & communication | 2018 |
| MIA Hara Ltd | Wholesale & retail | 2016 |
| Miah Spice Limited | Hospitality | 2017 |
| Miamox Ltd | Wholesale & retail | 2007 |
| Mibbit Ltd | Information & communication | 2020 |
| Micari Limited | Health & social care | 2023 |
| Micari Property Solutions Limited | Real estate | 2020 |
| Mices Ltd | Extraterritorial | 2006 |