| Medyahya Ltd | Wholesale & retail | 2025 |
| Medyaland Ltd | Information & communication | 2025 |
| Medyr CYF | Information & communication | 2016 |
| Medz Recruitment Group Ltd | Other services | 2024 |
| MEE Glazed Products Limited | Construction | 2014 |
| MEE Investment Ltd | Real estate | 2021 |
| Meek Consultancy Group Ltd | Professional & scientific | 2019 |
| Meekfields & Co Ltd | Professional & scientific | 2020 |
| Meem Academy for Consulting and Training Ltd | Wholesale & retail | 2022 |
| Meemit Ltd | Wholesale & retail | 2022 |
| Meerkat Properties Limited | Real estate | 2014 |
| Meeru Halal Meat Ltd. | Wholesale & retail | 2018 |
| Meet Greet Heathrow Parking Ltd | Transport & logistics | 2025 |
| Meet ME Here Limited | Wholesale & retail | 2023 |
| Mefill Limited | Hospitality | 2018 |
| MEG Residential Ltd | Real estate | 2023 |
| Meg-Bell Ltd | Other services | 2024 |
| Mega BPD Limited | Transport & logistics | 2017 |
| Mega Business World Ltd | Wholesale & retail | 2018 |
| Mega Electrical Solutions Ltd | Construction | 2024 |
| Mega Express Ltd | Transport & logistics | 2025 |
| Mega Infinite Capital Ltd | Information & communication | 2021 |
| Mega Tech Solutions Ltd | Information & communication | 2016 |
| Megacorp AUS Ltd | Administrative & support | 2021 |
| Megadraws Limited | Administrative & support | 2025 |
| Megalladon Ltd | Wholesale & retail | 2022 |
| Megalos Services Ltd | Manufacturing | 2025 |
| Megamalax Limited | Extraterritorial | 2014 |
| Megan Jungle Aesthetic Streetwear Limited | Wholesale & retail | 2026 |
| Megan Thomas Hair Ltd | Other services | 2020 |
| Megapharma Ltd | Manufacturing | 2012 |
| Megaprom Company Ltd | Manufacturing | 2018 |
| Megas Spin Ltd | Wholesale & retail | 2019 |
| Megascope Meridian Limited | Construction | 2022 |
| Megashops Ltd | Wholesale & retail | 2019 |
| Megastore TM Limited | Wholesale & retail | 2025 |
| Megatavan Limited | Construction | 2022 |
| Megatrend Investments Ltd | Health & social care | 2020 |
| Meggan Grubb Limited | Arts & recreation | 2018 |
| Megh Consulting Ltd | Professional & scientific | 2021 |
| Megmaefit Coaching Limited | Professional & scientific | 2021 |
| Megs Consultancy Ltd | Administrative & support | 2015 |
| Meharban Ltd | Wholesale & retail | 2025 |
| Mehbson Ltd | Information & communication | 2022 |
| Mehdi Logistics Ltd | Transport & logistics | 2025 |
| Mehedi Hossen Ltd | Wholesale & retail | 2025 |
| Mehmet's Barbers Limited | Other services | 2025 |
| Mehram Ltd | Wholesale & retail | 2025 |
| Mehroonlineshop Limited | Wholesale & retail | 2024 |
| Mehrsa Construction Limited | Construction | 2016 |
| Mehta Consultants Ltd | Health & social care | 2011 |
| Mehta Investors Ltd | Real estate | 2020 |
| Mehtaspine Ltd | Health & social care | 2011 |
| MEI DA Limited | Information & communication | 2025 |
| MEI KIT Limited | Information & communication | 2006 |
| Meikul Ltd | Wholesale & retail | 2025 |
| Meilan Business Limited | Wholesale & retail | 2025 |
| Meile Health Limited | Other services | 2021 |
| Meill Ltd | Wholesale & retail | 2025 |
| Meithrin Tredelerch Limited | Health & social care | 2021 |
| Meithrinfa Si-Lwli Nursery Limited | Health & social care | 2003 |
| Meithrinfa Y Pelican CYF. | Education | 2014 |
| Mekong Group Ltd | Construction | 2026 |
| Mekv Holdings Ltd | Construction | 2026 |
| MEL Capital Ltd | Financial services | 2026 |
| MEL H Davies Ltd | Health & social care | 2014 |
| MEL House Limited | Real estate | 2020 |
| Mela Technologies Ltd | Information & communication | 2025 |
| Melafun Ltd | Wholesale & retail | 2025 |
| Melagent Ltd | Transport & logistics | 2014 |
| Melanie Jayne Home Fragrance Co Ltd | Manufacturing | 2021 |
| Melany Medical Limited | Health & social care | 2015 |
| Melbourne and Masons Court Management Company Limited | Households | 2004 |
| Melbreak Consultants Limited | Administrative & support | 2012 |
| Melbro Limited | Wholesale & retail | 1991 |
| Melderm Ltd | Professional & scientific | 2010 |
| Meleb Ltd | Construction | 2018 |
| Meledo Company Limited | Wholesale & retail | 2018 |
| Melery Fashion Ltd | Wholesale & retail | 2025 |
| Meles Software Limited | Information & communication | 2008 |
| Melia.Ltt Ltd | Real estate | 2019 |
| Melido Ltd | Real estate | 2018 |
| Melifluo Paris Ltd. | Administrative & support | 2018 |
| Melihay Ltd | Wholesale & retail | 2025 |
| Meliora Black Gold Film Ltd | Information & communication | 2026 |
| Melissa Conway Limited | Health & social care | 1997 |
| Melissa Morgan Travel Ltd | Administrative & support | 2019 |
| Melissa Sophia Creative Limited | Arts & recreation | 2019 |
| Melkem Limited | Health & social care | 2014 |
| Mellak Ltd | Information & communication | 2025 |
| Mellberry Ltd | Wholesale & retail | 2020 |
| Mellisa PC | | 2014 |
| Mello London Ltd | Manufacturing | 2016 |
| Mellor & Combes Consultancy Limited | Other services | 2018 |
| Melloware Ltd | Information & communication | 2026 |
| Mells Energy Limited | Other services | 2025 |
| Melo Hair Ltd | Real estate | 2019 |
| Melodi Entertainment Limited | Information & communication | 2025 |
| Melody Music Company Limited | Administrative & support | 2003 |
| Meloncube Limited | Professional & scientific | 2019 |