| Luxix Nails Ltd | Other services | 2022 |
| Luxlim Limited | Wholesale & retail | 1988 |
| Luxury Lounge Ltd | Information & communication | 2026 |
| Luxury Representation Collection Limited | Professional & scientific | 2007 |
| LW Playbook Limited | Other services | 2025 |
| Lyallpur Motors Limited | Wholesale & retail | 2024 |
| Lyford Estates Limited | Extraterritorial | 2010 |
| Lykosrf Ltd | Manufacturing | 2025 |
| Lyncares' Ltd | Education | 2022 |
| Lyndale Property Bingley Limited | Real estate | 2014 |
| Lynx Security Ltd | Administrative & support | 2025 |
| Lynxfile Ltd | Information & communication | 2026 |
| Lyons Restoration Limited | Other services | 2013 |
| Lyra Visuals Ltd | Information & communication | 2025 |
| M & M Trading Limited | Wholesale & retail | 2012 |
| M & K Transport Services (H.W) Ltd | Transport & logistics | 2014 |
| M & N Construction Limited | Construction | 2001 |
| M a Callanan Haulage Ltd | Water & waste | 2007 |
| M a Shepherd Limited | Professional & scientific | 2010 |
| M Antinoro Limited | Arts & recreation | 2017 |
| M B Electrical (London) Ltd | Construction | 2004 |
| M B Supply Services Limited | Administrative & support | 2006 |
| M Construct Limited | Construction | 2019 |
| M D Food Services Ltd | Wholesale & retail | 2015 |
| M D Stacey Glazing Ltd | Construction | 2024 |
| M DIN Metal Traders Limited | Wholesale & retail | 2018 |
| M Glynn Builders Limited | Construction | 2007 |
| M Green Electrical Ltd | Construction | 2025 |
| M H Agriculture Ltd | Agriculture & fishing | 2024 |
| M Hale Limited | Construction | 2018 |
| M Hanif Properties Ltd | Real estate | 2019 |
| M J Accountants Ltd | Professional & scientific | 2020 |
| M K Fire Limited | Other services | 1987 |
| M P Ferguson Ltd | Construction | 2005 |
| M Powell Contractors Limited | Other services | 2016 |
| M R Engineering Design Ltd | Professional & scientific | 2014 |
| M R Hewitt Associates Limited | Professional & scientific | 2011 |
| M R Planning Ltd | Professional & scientific | 1999 |
| M Spread Ltd | Health & social care | 2022 |
| M T Messenger Estates Limited | Real estate | 2010 |
| M&B Properties Ltd | Hospitality | 2026 |
| M&G Parties Ltd | Other services | 2023 |
| M&J Global Services Ltd | Construction | 2023 |
| M&K Engineering Ltd | Wholesale & retail | 2019 |
| M&M Spicy Grill Ltd | Hospitality | 2024 |
| M&S Crescent Limited | Construction | 2006 |
| M'Tainment Media Limited | Information & communication | 2025 |
| M-Craft Construction Ltd | Construction | 2016 |
| M. Flegg Transport Limited | Transport & logistics | 2002 |
| M.A & Co (U.K ) Limited | Professional & scientific | 2017 |
| M.A.B. Media Limited | Professional & scientific | 2017 |
| M.Gphotography for ME Ltd | Professional & scientific | 2025 |
| M.J.S Building & Property Services Ltd | Construction | 2020 |
| M.M.D GAS Services Limited | Construction | 2019 |
| M.N Azad Construction Ltd | Construction | 2025 |
| M.R (Essentials) Group Ltd | Wholesale & retail | 2026 |
| M2 Sports Management Limited | Professional & scientific | 2010 |
| M3J Investments Limited | Real estate | 2017 |
| M4 Design Ltd | Professional & scientific | 2019 |
| M40 LPG Ltd | Energy | 2025 |
| M40 Motors Limited | Wholesale & retail | 2025 |
| M40 Pallets Limited | Wholesale & retail | 2001 |
| MA Auto Repair Limited | Wholesale & retail | 2023 |
| MA Auto Trading Ltd | Wholesale & retail | 2025 |
| Maacro Consultancy Limited | Professional & scientific | 2023 |
| Maaha Trading Ltd | Administrative & support | 2022 |
| Maas Properties Ltd | Real estate | 2003 |
| Maasy Limited | Information & communication | 2014 |
| MAB Research & Consulting Limited | Professional & scientific | 2022 |
| Mabel Daniel Ltd | Health & social care | 2015 |
| Mabel Management Ltd | Construction | 2026 |
| Mabk Property Investments Limited | Real estate | 2024 |
| Maccintosh Ltd | Wholesale & retail | 2024 |
| Macintosh Mills Car Park (Management) Limited | Extraterritorial | 2006 |
| Mack Consulting Limited | Professional & scientific | 2009 |
| Mackinney Education Limited | Education | 2022 |
| Mackinney Timetabling Limited | Professional & scientific | 2023 |
| Mackling Ltd | Real estate | 2023 |
| Macu Ltd | Transport & logistics | 2019 |
| MAD Monkeys Trading Ltd | Hospitality | 2012 |
| Made by Brittan Ltd | Administrative & support | 2012 |
| Made by Jules Ltd | Manufacturing | 2026 |
| Made by Omni Limited | Manufacturing | 2018 |
| Made Training Limited | Education | 2010 |
| Madenbridge Limited | Real estate | 1997 |
| Madfun Limited | Manufacturing | 2006 |
| Madhav Catering Services Limited | Hospitality | 2026 |
| Madhuvan Hospitality Ltd | Hospitality | 2023 |
| Madiana Ltd | Professional & scientific | 2023 |
| Madina Residences Ltd | Real estate | 2025 |
| MADINAH786 Limited | Other services | 2026 |
| Madycleaning Ltd | Administrative & support | 2026 |
| Maestro Drapes Ltd | Manufacturing | 2026 |
| MAG Project Management Limited | Professional & scientific | 2011 |
| MAG Property Group Ltd | Real estate | 2020 |
| Magic Builders Ltd | Construction | 2010 |
| Magic Delivery Experts Ltd | Wholesale & retail | 2021 |
| Magic Letterbox Limited | Information & communication | 2026 |
| Magic Sparkle Cleaning Ltd | Administrative & support | 2020 |
| Magic UK Food Limited | Hospitality | 2024 |