| Magic Ring O Bells Ltd | Hospitality | 2025 |
| Magic Scissors Limited | Other services | 2003 |
| Magic the Cat Group Ltd | Financial services | 2025 |
| Magic the Cat Ltd | Hospitality | 2013 |
| Magic Touch Catering Equipment Ltd | Manufacturing | 2025 |
| Magic WOK Bristol Ltd | Hospitality | 2025 |
| Magicbox Entertainment Limited | Arts & recreation | 2021 |
| Magician Limited | Households | 1981 |
| Magm-Rdr Ltd | Professional & scientific | 2019 |
| Magma Amplification Limited | Manufacturing | 2021 |
| Magna Healthcare Limited | Wholesale & retail | 2014 |
| Magna Opera Ltd | Information & communication | 2019 |
| Magna-Ascent Investments Ltd | Professional & scientific | 2026 |
| Magners GB Limited | Manufacturing | 2009 |
| Magnesium Creative Ltd | Administrative & support | 2009 |
| Magnifera Indica Ltd | Wholesale & retail | 2025 |
| Magnifi Limited | Professional & scientific | 2013 |
| Magnit Building Trader Service Ltd | Construction | 2017 |
| Magnolia Mews Bakehouse Ltd | Hospitality | 2022 |
| Magnolia Property Developments Limited | Professional & scientific | 1994 |
| Magnum Groundworker Ltd | Construction | 2023 |
| Magnum Scaffolding (Contracts) Limited | Construction | 2012 |
| Magnum Scaffolding Limited | Administrative & support | 2004 |
| Magnum Truck and Van Limited | Extraterritorial | 2024 |
| Magnus Auto Recovery Ltd | Other services | 2018 |
| Magnus Pettersen Studio Limited | Wholesale & retail | 2021 |
| Magnus Services Limited | Other services | 2009 |
| Magpie & Mint Limited | Information & communication | 2012 |
| Magpie Gardens Residents Management Company Limited | Households | 2010 |
| Magpie Inventory Services Limited | Administrative & support | 2021 |
| Magpie Lets Limited | Real estate | 2017 |
| Magpie Metal & Waste Limited | Wholesale & retail | 2014 |
| Magpie Scaffolding Ltd | Construction | 2022 |
| Magro Foods (UK) Limited | Hospitality | 2009 |
| Magwadas CIC | Information & communication | 2026 |
| Mahadev Haulage Ltd | Transport & logistics | 2026 |
| Mahalah Consulting Limited | Professional & scientific | 2022 |
| Mahavir Construction Limited | Real estate | 2019 |
| Mahavir Consultancy Services Ltd. | Information & communication | 2022 |
| Mahdy Spice Limited | Hospitality | 2024 |
| Mahek Bristol Limited | Hospitality | 2018 |
| Mahi RAJ Ltd | Hospitality | 2021 |
| Mahika Kala Ltd | Wholesale & retail | 2026 |
| Mahir Care Ltd Limited | Wholesale & retail | 2025 |
| Mahmud Rasel Ltd | Transport & logistics | 2025 |
| Mahrous Limited | Hospitality | 2021 |
| MAI BUI Consultancy Limited | Professional & scientific | 2021 |
| Maia Designs Ltd | Professional & scientific | 2025 |
| Maid in Bristol Cleaning Services Ltd | Administrative & support | 2019 |
| MAID2CLEAN (Dust 'N' Shine) Ltd | Administrative & support | 2012 |
| Maida Fintech Limited | Professional & scientific | 2024 |
| Mail a DOC Limited | Administrative & support | 2007 |
| Mail Handling International Limited | Transport & logistics | 1996 |
| Mailgreen Limited | Transport & logistics | 2009 |
| Main Interior Design Ltd | Professional & scientific | 2018 |
| Main Kids Limited | Manufacturing | 2007 |
| Main Street Exit Limited | Professional & scientific | 2025 |
| Maine Pointe Limited | Professional & scientific | 2016 |
| Mainstone Heating Limited | Construction | 2011 |
| Mainstone Investments Limited | Real estate | 2004 |
| Mainstream Maintenance (South West) Ltd | Construction | 2020 |
| Maintain More Ltd | Manufacturing | 2021 |
| Maintain-A-Drain (South West) Limited | Extraterritorial | 2012 |
| Maintenance & Contracting Services Ltd | Professional & scientific | 2006 |
| Maintenance Response Electrical Division Limited | Construction | 2020 |
| Maintenance Response Ltd | Construction | 2019 |
| Maintenance Services Direct Ltd | Extraterritorial | 2014 |
| Maintenance Services Ltd | Extraterritorial | 2018 |
| Maintenance SW Ltd | Construction | 2023 |
| Maiora IT Services and Consulting Ltd | Information & communication | 2021 |
| Maisie Court Freehold Limited | Households | 2018 |
| Maison 64 Ltd | Real estate | 2022 |
| Maison Developments Limited | Real estate | 2005 |
| Maison Jade Limited | Households | 2025 |
| Maison K&B Ltd | Wholesale & retail | 2025 |
| Maison Modesty Ltd | Wholesale & retail | 2022 |
| Maitiu Group Ltd | Hospitality | 2024 |
| Maitland & Poate Ltd | Wholesale & retail | 2013 |
| Majestic Mile Chauffeurs Limited | Transport & logistics | 2022 |
| Majestic Prepared Food Services Ltd. | Manufacturing | 2019 |
| Majjigas Limited | Real estate | 2025 |
| Major Minor Productions Limited | Arts & recreation | 2019 |
| Major Solutions Security Services Ltd | Administrative & support | 2026 |
| Major Worktops Limited | Construction | 2018 |
| MAJOR1 Tsimavor Ltd | Wholesale & retail | 2017 |
| Majorbymm Ltd | Professional & scientific | 2025 |
| MAK and Co Ltd | Wholesale & retail | 2014 |
| MAK41 Ltd | Hospitality | 2025 |
| Maka & Kidz Limited | Health & social care | 2024 |
| Makadesa Properties Ltd | Real estate | 2025 |
| Makan Flats Ltd | Households | 2014 |
| Make Bespoke Limited | Construction | 2018 |
| Make by Design Limited | Professional & scientific | 2018 |
| Make Digital Count Limited | Information & communication | 2023 |
| Make Estates Limited | Construction | 2018 |
| Make Foundation Ltd | Health & social care | 2021 |
| Make Group Limited | Construction | 2015 |
| Make Happen CIC | Education | 2015 |
| Make Happen NOW Ltd | Education | 2021 |
| Make Health Human Ltd | Professional & scientific | 2023 |