| Merit (SW) Ltd | Construction | 2015 |
| Meritemploy Ltd | Extraterritorial | 2025 |
| Meriton Foundry Ltd | Real estate | 2017 |
| Merj Marketing Limited | Professional & scientific | 2015 |
| Merlin Decorators South West Ltd | Construction | 2017 |
| Merlin Financial Consulting Limited | Professional & scientific | 2026 |
| Merlin Lifts Limited | Manufacturing | 2021 |
| Merlin Moosik UK Ltd | Wholesale & retail | 2026 |
| Merlinc (SW) Limited | Hospitality | 2003 |
| Merlins Wand Ltd | Other services | 2025 |
| Mernco Ltd | Other services | 2017 |
| Mero Barber Ltd | Other services | 2025 |
| Merop Consulting Ltd | Real estate | 2021 |
| Merop Real Estate Ltd | Real estate | 2024 |
| Merrett Estate Planning Limited | Professional & scientific | 2019 |
| Merrick Court Management Limited | Households | 1986 |
| Merrifield Properties Ltd | Real estate | 2025 |
| Merrigan-Reis Estates Limited | Real estate | 2024 |
| Merrin Auto Services Ltd | Wholesale & retail | 2015 |
| Merrion Holdings Ltd | Real estate | 2015 |
| Merrion Pet Co Ltd | Wholesale & retail | 2026 |
| Merry Harriers Limited | Hospitality | 2017 |
| Merry Hill Community Association Ltd | Households | 2021 |
| Merrywood Court Upper Knowle Management Company Limited | Households | 2001 |
| Merrywood UK Investment Limited | Real estate | 2022 |
| Merttlamama Ltd | Professional & scientific | 2026 |
| Mervarde Ltd | Professional & scientific | 2012 |
| Mervyn Entertainment Ltd | Arts & recreation | 2024 |
| Merx Ltd | Information & communication | 2024 |
| Mery and Mels International Ltd | Extraterritorial | 2025 |
| Meryl Court Management Limited | Households | 1979 |
| MES Electrical Services (Bristol) Ltd | Construction | 2024 |
| MES Sports Limited | Other services | 2023 |
| Mesco Consulting Limited | Information & communication | 1998 |
| Mesh Engineering Ltd | Professional & scientific | 2019 |
| Mesh Projects Limited | Professional & scientific | 2009 |
| Meshamo Ltd | Information & communication | 2019 |
| Meshworks Productions Limited | Professional & scientific | 2022 |
| Messages From the Wild Limited | Arts & recreation | 2019 |
| MESSIER42 Ltd | Real estate | 2019 |
| Mesulak Limited | Administrative & support | 2026 |
| MET Healthcare UK Limited | Wholesale & retail | 2020 |
| Meta Sale Group Ltd | Wholesale & retail | 2019 |
| Meta Synergy Marketing Ltd | Professional & scientific | 2023 |
| Meta Synergy Tech Ltd | Information & communication | 2023 |
| Metabolic Profiling Forum | Professional & scientific | 2007 |
| Metacraft Marketing Ltd | Other services | 2007 |
| Metal Spray Coatings Ltd | Manufacturing | 2022 |
| Metalife Marketing Limited | Professional & scientific | 2024 |
| Metalline Signs Limited | Professional & scientific | 1975 |
| Metalworx Roofing & Cladding Ltd | Construction | 2023 |
| Metam Consultancy Ltd | Professional & scientific | 2023 |
| Metamorph VFX Ltd | Professional & scientific | 2013 |
| Metamu Ltd | Professional & scientific | 2025 |
| Metapharm Limited | Health & social care | 2015 |
| Metaquila Limited | Professional & scientific | 2019 |
| Metasoft Consulting Ltd | Administrative & support | 2015 |
| Metaura Limited | Other services | 2020 |
| Metcalfe & HO Ltd | Hospitality | 2023 |
| Metcalfe Design Ltd | Professional & scientific | 2020 |
| Meteor Pixel Ltd | Information & communication | 2016 |
| Metes Foundation | Education | 2022 |
| Method Bar Ltd | Hospitality | 2003 |
| Method Construction Limited | Construction | 2024 |
| Method Endurance Ltd | Education | 2026 |
| Method Land and Development Limited | Construction | 2026 |
| Method Resourcing Solutions Limited | Administrative & support | 2018 |
| Methuen One Management Company Limited | Real estate | 2025 |
| Meticulous Holdings Limited | Real estate | 2015 |
| Metrem Limited | Manufacturing | 2024 |
| Metric and Motive Ltd | Information & communication | 2024 |
| Metric Lighting Services Ltd | Professional & scientific | 2025 |
| Metric Windows Limited | Manufacturing | 2006 |
| Metro Distributors Limited | Wholesale & retail | 2016 |
| Metro Express Central Limited | Other services | 2014 |
| Metro North Limited | Professional & scientific | 2001 |
| Metro-Cammell Weymann Ltd | Extraterritorial | 2010 |
| Metrodental Limited | Health & social care | 2006 |
| Metrofreight Limited | Transport & logistics | 1995 |
| Metropolis Design Ltd | Information & communication | 2023 |
| Metropolis Security Limited | Administrative & support | 1998 |
| Metrum Ltd | Real estate | 2020 |
| Mets Marine Consultancy Ltd. | Professional & scientific | 2015 |
| Mevalco (Fine Foods From Spain) Limited | Wholesale & retail | 2007 |
| Mevamed Ltd | Health & social care | 2020 |
| Mews Management Company (Leigh Woods) Limited | Households | 1983 |
| Mewslade Properties Limited | Other services | 2014 |
| Mexboro Concrete Limited | Manufacturing | 1960 |
| Mezbrod Ltd | Real estate | 2019 |
| Mezky Ltd | Manufacturing | 2018 |
| Mezzaluna Bristol Ltd | Hospitality | 2026 |
| Mezze Software Ltd | Information & communication | 2021 |
| MF & CT Holdings Limited | Financial services | 2019 |
| MF Home Solutions Ltd | Construction | 2022 |
| MF Software Solutions Limited | Other services | 2002 |
| MF Solutions (Tech Services) Limited | Wholesale & retail | 2014 |
| MFB Education Centre Ltd | Education | 2020 |
| MFE Engineering Ltd | Mining & quarrying | 2024 |
| MFJ Electrical Services Ltd | Construction | 2026 |
| Mfk-Treyd Ltd | Manufacturing | 2024 |