| Micron Instruments UK Limited | London | 2026 |
| MID Cornwall Speech and Language Therapy Limited | Truro | 2025 |
| MID Kent Enforcement Ltd | Maidstone | 2020 |
| Mid-View Healthcare Ltd | Birmingham | 2020 |
| Mideh Services Ltd | London | 2022 |
| Mideiva Limited | Cardiff | 2022 |
| Midland Fire Protection Services Limited | Coventry | 1998 |
| Midland Markets & Marshals Limited | Bewdley | 2019 |
| Midlands Ambulance Group Ltd | Swadlincote | 2020 |
| Midlands Assess Ltd | Sleaford | 2026 |
| Midlands Community Care Ltd | Walsall | 2022 |
| Midlands Fire Extinguishers Ltd | Derby | 2023 |
| Midlands Fire Protection Ltd | Leicester | 2025 |
| Midlands Haven Homes Ltd | Daventry | 2024 |
| Midlands Healthy Horizons Limited | Solihull | 2013 |
| Midlands Medicare Agency Ltd | Birmingham | 2017 |
| Midlandsfrs Limited | Stone | 2019 |
| Mighty Health Care Limited | Cardiff | 2020 |
| Migrash Ltd | Milton Keynes | 2022 |
| Mika Horizons Limited | Wallington | 2026 |
| Mike Wilkins Consultancy Services Limited | London | 2005 |
| Mikvan Limited | Haverfordwest | 2023 |
| MILAVANNI16+ Limited | London | 2020 |
| Military Storage Solutions Ltd | Milton Keynes | 2019 |
| Milkor UK Ltd | London | 2026 |
| Millets Healthcare Provider Limited | Manchester | 2022 |
| Millhaven Fire Risk Management Ltd | Birmingham | 2024 |
| Millie-Rose Solutions Ltd | Bedford | 2020 |
| Mills Commercials & Fire Doors Limited | Towcester | 2024 |
| Millwood Services Limited | Horsham, | 1984 |
| Milnatney Ltd | Halesowen | 2021 |
| Milo Care Services Limited | Nottingham | 2019 |
| Milo UK Consulting Ltd | Harlow | 2019 |
| Mimi D Ltd | Ilford | 2023 |
| Minat Consultancy Limited | Bolton | 2023 |
| Mina’S Care Limited | Liverpool | 2022 |
| Minchneat Services Ltd | Hitchin | 2021 |
| Mind & Beyond Healthcare Ltd | Runcorn | 2024 |
| Mind and Body Connections Ltd | Chelmsford | 2023 |
| Mind and Strength Ltd | Bracknell | 2021 |
| Mind BE Growing Ltd | London | 2018 |
| Mind Blossom and Bloom Ltd | Cobham | 2023 |
| Mind Health Doctors Rumi Community Interest Company | London | 2024 |
| Mind Safety Group Ltd | Reading | 2023 |
| Mind SET for Work Ltd | Marlborough | 2025 |
| Mind YOU Health & Wellbeing CIC | Roslin | 2021 |
| Mindbridge Education Group Limited | Towcester | 2025 |
| Mindcalm Coach Limited | London | 2025 |
| Mindflix Media Ltd | Telford | 2022 |
| Mindfocus Health Ltd | London | 2026 |
| Mindful Mamahood CIC | London | 2025 |
| Mindful Medix CPD Ltd | Ellesmere Port | 2026 |
| Mindful Support Ltd | High Wycombe | 2025 |
| Mindhug Impact CIC | Stowmarket | 2025 |
| Mindjam Community CIC | Lincoln | 2023 |
| Mindscape London Ltd | Purley | 2024 |
| Mindset Mentors (Private) Limited | Oldham, United Kingdom | 2026 |
| MINE80 Limited | Derby | 2025 |
| Mineral Resources Professional Limited | Bristol | 2013 |
| Ming Healthcare Ltd | London | 2018 |
| Mira Express Services Limited | Dundee | 2022 |
| Miracle Solutions Ltd | London | 2024 |
| Miranzi Healthcare Ltd | Bromley | 2019 |
| Mireille Care Solution Private Limited | Manchester | 2020 |
| Mirella Tradings (Private) Limited | Oldham, United Kingdom | 2026 |
| Miri Care Ltd | Enfield | 2022 |
| Mirla Health Ltd | London | 2024 |
| Mirren Event Safety Limited | Glasgow | 2022 |
| Mirth Group Limited | Pontypridd | 2022 |
| Mission Ability Ltd | Bury St. Edmunds | 2025 |
| Mistek Limited | Rochester | 2016 |
| Mistura Consultancy Services Limited | Gillingham | 2004 |
| MIT Health Safety & Environment Limited | United Kingdom | 2014 |
| Mitchell & Cleary Ltd | Herne Bay | 2019 |
| Mitchell Fire Protection Limited | Mansfield | 2007 |
| Mitchell's Healthcare Training Ltd | Inverness | 2025 |
| Mitec Safety Management Limited | Sittingbourne | 2015 |
| Mithus & Mithoon(M&M) Healthcare Limited | Blackpool | 2025 |
| Mizoa Services Ltd | Cardiff | 2020 |
| MJ Physio Ltd | Doncaster | 2020 |
| MJB Fire Protection Ltd | Hamilton | 2019 |
| MJB NW Ltd | Blackpool | 2025 |
| MJG Care Service Ltd | London | 2022 |
| Mjln TM Ltd | Doncaster | 2025 |
| MJP Electrical Estimating Limited | Downham Market | 2014 |
| MJS Fire Ltd | Loughton | 2025 |
| MJX Healthcare Limited | Woodford Green | 2023 |
| MK Fire & Security Ltd | Newton Abbot | 2022 |
| MK Fire Consultants Ltd | Dungannon | 2022 |
| MK Fire Protection Service & Maintenance Ltd | Glasgow | 2019 |
| MK Haven Care Services Ltd | Milton Keynes | 2025 |
| Mkay Consultancy Limited | Cambridge | 2018 |
| MKB Business Solutions Limited | London | 2016 |
| MKB Fire and Security Ltd | Leatherhead | 2025 |
| MKB Fire Safety Ltd | Warrington | 2020 |
| MKB Fire Services Limited | Belfast | 2017 |
| MKD Empowerment | London | 2024 |
| Mkfco Limited | London | 2024 |
| MKH Supported Living Limited | London | 2023 |
| Mkheswa Limited | Willenhall | 2018 |