| Marshall Investment Holdings Limited | Financial services | 2025 |
| Matrideus Ltd | Professional & scientific | 2025 |
| Matt Burrows Construction Ltd | Construction | 2006 |
| Matthew H Thomas Ltd | Health & social care | 2025 |
| Mattoid Ltd | Wholesale & retail | 2026 |
| Maytree Consulting Limited | Other services | 2006 |
| MB Scaffolding Ltd | Construction | 2018 |
| Mccombe Design Limited | Professional & scientific | 2017 |
| Meadow Haven Ltd | Other services | 2025 |
| Metacrux Ltd | Professional & scientific | 2017 |
| Meteograms Ltd | Information & communication | 2021 |
| Miba Europe Ltd | Wholesale & retail | 2006 |
| Midas AI ZFE Limited | Other services | 2025 |
| Mike Nichols Personal Training and Nutrition Ltd | Administrative & support | 2017 |
| Mike Rigby Consulting Limited | Professional & scientific | 2022 |
| Mikro Limited | Administrative & support | 2002 |
| Milbury Heath Commercials Limited | Wholesale & retail | 1994 |
| Minims Music Education Limited | Education | 2025 |
| Mirwell Finance Limited | Financial services | 2023 |
| ML Business Support Ltd | Professional & scientific | 2021 |
| Moltobuono Ltd | Hospitality | 2025 |
| Moore's Custom Campers Ltd | Manufacturing | 2014 |
| Morgans Technical Books Limited | Information & communication | 1984 |
| Morley Lanes Management Company Limited | Households | 1992 |
| Motley Zero Alpha Ltd | Wholesale & retail | 2025 |
| Motovia Ltd | Wholesale & retail | 2025 |
| Mountain Kingdoms Ltd | Administrative & support | 1987 |
| Mozart Symphony Orchestra Limited | Arts & recreation | 2008 |
| MRA Building Market Reports Limited | Professional & scientific | 2025 |
| MRA Data Services Limited | Information & communication | 1987 |
| MSB Electrics Limited | Construction | 2017 |
| MTT Investments Limited | Extraterritorial | 2007 |
| MTT Technologies Limited | Extraterritorial | 2000 |
| MUC1 Limited | Administrative & support | 2025 |
| MUK 1 Limited | Construction | 2016 |
| My Family Tree Ltd. | Professional & scientific | 2016 |
| Mynthurst Estates Limited | Agriculture & fishing | 2021 |
| N.W.A. Lang Limited | Construction | 2002 |
| Naiada Ltd | Information & communication | 2025 |
| Neales Financial Management Holdings Limited | Financial services | 2005 |
| Neales Financial Management Limited | Financial services | 1999 |
| Neave Associates Ltd | Manufacturing | 1997 |
| New G Limited | Arts & recreation | 2023 |
| New Home Construction Ltd | Construction | 2016 |
| Nexcen Limited | Information & communication | 1999 |
| Next Best Action Ltd | Information & communication | 2017 |
| Nhne Limited | Information & communication | 2020 |
| Noguer Holdings Limited | Financial services | 2025 |
| Norace Ltd | Hospitality | 2016 |
| Northend Technology Ltd | Information & communication | 2022 |
| Nuwave IT Consultancy Ltd | Information & communication | 2024 |
| Oakhall Farm LLP | | 2024 |
| Oasis Consultation Ltd | Hospitality | 2020 |
| Obarac Limited | Professional & scientific | 2010 |
| Octavia Dickinson Ltd | Professional & scientific | 2018 |
| Oh-So-Clean Limited | Administrative & support | 2012 |
| Old Court House (Wotton-Under-Edge) Limited(The) | Households | 1984 |
| Old White Horse Management Ltd | Households | 2026 |
| Olive Grove Collective Ltd | Information & communication | 2025 |
| Omerta Worldwide Sportfishing Charters Limited | Arts & recreation | 2021 |
| Omniserve Ltd | Agriculture & fishing | 2022 |
| One 80 (UK) Ltd | Wholesale & retail | 2017 |
| One Vision Creations Ltd | Construction | 2025 |
| One World Trust | Professional & scientific | 2008 |
| Onward Engineering Solutions Limited | Professional & scientific | 2015 |
| Optimise QI Ltd | Professional & scientific | 2023 |
| Optimus Woods Ltd | Construction | 2021 |
| Orleyton Ltd | Information & communication | 2020 |
| Outdoor Play West Limited | Education | 2022 |
| Ovalshelfco (Number Eighty Seven) Limited | Real estate | 1982 |
| P & P (Occupational Health & Safety) Limited | Professional & scientific | 1998 |
| P T Newnes Plumbing & Heating Limited | Construction | 2025 |
| P. N. Architecture Ltd | Professional & scientific | 2019 |
| P.A. Sales Limited | Wholesale & retail | 1987 |
| Page Build Limited | Construction | 2023 |
| Paint FIX Bodyshop Ltd | Wholesale & retail | 2020 |
| Painted Curb Limited | Professional & scientific | 2021 |
| Palmer & Cook Ltd | Professional & scientific | 2008 |
| Parkhills Tetbury Limited | Real estate | 2026 |
| Paul Winslet Mrics Ltd | Professional & scientific | 2025 |
| Pedington Limited | Construction | 2008 |
| Penguin Construction Ltd | Construction | 2023 |
| PER Diem Consulting Limited | Hospitality | 2008 |
| Pet Planet Limited | Wholesale & retail | 2007 |
| Philip Turley Landscapes Ltd | Administrative & support | 2025 |
| Phoebe Dickinson Ltd | Arts & recreation | 2021 |
| Phonetalk Communications Ltd | Information & communication | 2015 |
| Pick Property Limited | Real estate | 2025 |
| Pines Land and Property Developments Limited | Construction | 2026 |
| Pool Water Solutions.Co.Uk Limited | Administrative & support | 2012 |
| Positive Context Limited | Information & communication | 2023 |
| Press Play Learning Ltd | Education | 2021 |
| Press Rockhaven Limited | Wholesale & retail | 2025 |
| Preveda Limited | Real estate | 1994 |
| Procalus Limited | Professional & scientific | 2024 |
| Productivity Wolf Ltd | Information & communication | 2026 |
| PRW Plumbing & Heating Ltd | Construction | 2006 |
| Purple Pebbles Limited | Professional & scientific | 2023 |
| Pécheresse Limited | Wholesale & retail | 2023 |
| Quanta Controls Ltd | Construction | 2012 |