| Mackenzie Staton Ltd | Wholesale & retail | 2014 |
| Macku Holdings Limited | Other services | 2023 |
| Maclayen Traders Ltd | Wholesale & retail | 2024 |
| Maclean Moore Group Limited | Financial services | 2018 |
| Macloughlin Carbis Bay Limited | Hospitality | 2015 |
| Macmillan Rich Limited | Administrative & support | 2014 |
| Macnab Property Limited | Real estate | 2015 |
| Macolie Trade Ltd | Hospitality | 2026 |
| Macquillan MCS Limited | Health & social care | 2014 |
| Macquillan MLS Limited | Health & social care | 2014 |
| Macquillan Properties Limited | Health & social care | 2014 |
| Macrae Road Limited Liability Partnership | | 2007 |
| Macriloda Property Ltd | Real estate | 2016 |
| Macrita Housing Ltd | Real estate | 2025 |
| Macrita Ltd | Health & social care | 2014 |
| Macro Decisions LLP | | 2010 |
| Macro Investments Ltd | Households | 2020 |
| Macro Solutions Tools Ltd | Information & communication | 2024 |
| Macsco 25 Limited | Real estate | 2010 |
| Macstaff Limited | Administrative & support | 2015 |
| Mactaggart Scott (UK) Limited | Extraterritorial | 2014 |
| Macvies Caring Limited | Health & social care | 2016 |
| MAD Apper Studios Limited | Information & communication | 2022 |
| MAD Apple Imports & Exports Ltd | Wholesale & retail | 2013 |
| MAD Chase Co Ltd | Financial services | 2016 |
| MAD COW Developments Ltd | Real estate | 2025 |
| MAD Digs Ltd | Real estate | 2025 |
| MAD Jeff Promotions Limited | Real estate | 1984 |
| MAD Skin Wear Limited | Wholesale & retail | 2025 |
| MAD Solutions Bristol Ltd | Professional & scientific | 2021 |
| Madam Two Saws Ltd | Arts & recreation | 2016 |
| Madavies Scaffolding Ltd | Construction | 2025 |
| Madbor Ltd | Wholesale & retail | 2021 |
| Maddox Design Ltd | Administrative & support | 2002 |
| Maddrell Consultancy Services Limited | Construction | 2002 |
| Made 4 Space Ltd | Manufacturing | 2018 |
| Made by Lenee Ltd. | Wholesale & retail | 2020 |
| Made by Olivia Ltd | Administrative & support | 2020 |
| Made by Unfold Ltd | Information & communication | 2020 |
| Made by Yasmin Limited | Manufacturing | 2018 |
| Made for Impact Limited | Information & communication | 2022 |
| Made in Bristol Shop Limited | Wholesale & retail | 2014 |
| Made IT Happen Ltd | Arts & recreation | 2019 |
| Made on the Moon CIC | Information & communication | 2024 |
| Made YOU Look Studios Ltd | Information & communication | 2025 |
| Madebymeta Limited | Professional & scientific | 2018 |
| Madebyorigin Ltd | Manufacturing | 2026 |
| Madeleine Locations Ltd | Information & communication | 2025 |
| Madeleine Woof Psychotherapy Services Ltd | Education | 2019 |
| Mademed Ltd | Health & social care | 2020 |
| Madera Consulting Limited | Information & communication | 2026 |
| Madera UK Limited | Professional & scientific | 2009 |
| Madeye Trading Ltd | Financial services | 2019 |
| Madhira Consultancy Services Ltd | Information & communication | 2013 |
| Madiha Khan MUA Ltd | Other services | 2020 |
| Madina Bazar Ltd | Wholesale & retail | 2025 |
| Madina Fish Bar Limited | Hospitality | 2024 |
| Madison CRT (Bristol) Management Company Limited | Households | 2025 |
| Madison-Rae Ltd | Other services | 2018 |
| Madisons Bristol Ltd | Hospitality | 2024 |
| Madleys Exterior Cleaning Services Ltd | Administrative & support | 2020 |
| Madras Junction Ltd | Hospitality | 2023 |
| Madszyd Ltd | Information & communication | 2016 |
| Maducleaning Ltd | Administrative & support | 2024 |
| Maef Care Ltd | Health & social care | 2025 |
| Maeforth Consulting Ltd | Extraterritorial | 2025 |
| Maeforth Events Ltd | Extraterritorial | 2025 |
| Maeme's Burger Limited | Hospitality | 2024 |
| Maeme's Easton Ltd | Hospitality | 2025 |
| Maemes Bristol Ltd | Administrative & support | 2019 |
| Maemes Grill Ltd | Hospitality | 2023 |
| Maestri Consultancy Ltd | Construction | 2025 |
| Maestro Data Services Ltd | Information & communication | 2026 |
| Maevis Limited | Wholesale & retail | 2020 |
| Mafia Weekend CIC | Information & communication | 2022 |
| Magali Epin Ltd | Real estate | 2015 |
| Magans Taxis Limited | Transport & logistics | 2011 |
| Magari Group Limited | Hospitality | 2021 |
| Magchap Healthcare Ltd | Health & social care | 2021 |
| Magdalena Court RTM Company Limited | Households | 2010 |
| Magellan-Group Ltd | Professional & scientific | 2022 |
| Magenta Consultancy Services Ltd | Professional & scientific | 2021 |
| Maggie MAY Media Ltd. | Manufacturing | 2018 |
| Maggs & Templar Renovations Ltd | Construction | 2022 |
| Maggs Agricultural and Silvicultural Ltd | Agriculture & fishing | 2020 |
| Maggs Housing Ltd | Real estate | 2022 |
| Maggs Property Investments Ltd | Real estate | 2024 |
| Maggs Renovations Limited | Construction | 2019 |
| Magi-Cut Software Limited | Information & communication | 1983 |
| Magia Limited | Health & social care | 2019 |
| Magic Bars Leisure Ltd | Hospitality | 2016 |
| Magic Bean Counters Limited | Professional & scientific | 2003 |
| Magic Box Motion Pictures Limited | Information & communication | 1997 |
| Magic Broom Cleaning Ltd | Administrative & support | 2022 |
| Magic Dents Group Ltd | Wholesale & retail | 2016 |
| Magic Donkey Ltd | Information & communication | 2012 |
| Magic Hands Construction Ltd | Construction | 2024 |
| Magic Leap Europe Ltd | Information & communication | 2014 |
| Magic Masala Bristol Ltd | Hospitality | 2026 |
| Magic Mobility Ltd | Manufacturing | 2008 |