| Lychgate Consulting Ltd | Health & social care | 2023 |
| Lycia Direct Ltd | Professional & scientific | 2010 |
| Lycia Wealth Ltd | Financial services | 2011 |
| Lydian Stone Limited | Professional & scientific | 2019 |
| LYE Laundry Ltd | Other services | 2026 |
| LYG (Trading) Limited | Arts & recreation | 2004 |
| Lykke Construction Limited | Real estate | 2025 |
| Lykke Investments Limited | Real estate | 2025 |
| LYLA97 Ltd | Health & social care | 2024 |
| Lymans Consultancy Limited | Professional & scientific | 2009 |
| Lymcloud IT Services Ltd. | Information & communication | 2016 |
| LYN Sills Property Ltd | Extraterritorial | 2023 |
| Lynchdell Properties Limited | Real estate | 2016 |
| Lynco Limited | Public administration | 2014 |
| Lyndhurst Heating Limited | Construction | 2016 |
| Lynds Group Ltd | Hospitality | 2022 |
| Lynsted Properties Limited | Real estate | 1986 |
| Lynton & Malvern Ltd | Wholesale & retail | 2025 |
| Lyntouch Ltd | Information & communication | 2015 |
| Lynx Auto Centre Limited | Wholesale & retail | 1992 |
| Lynx Living Limited | Real estate | 2023 |
| Lynx Property Management Ltd | Real estate | 2023 |
| Lynx Property Partners Ltd | Real estate | 2025 |
| Lyon Hall Investments Ltd | Administrative & support | 2001 |
| Lyon Square Energy Management Company Limited | Households | 2015 |
| Lyon Square Management Company Limited | Households | 2015 |
| Lytix Ltd | Information & communication | 2022 |
| Lyve Group Ltd | Professional & scientific | 2020 |
| LZA Holdings Ltd | Real estate | 2025 |
| Lzhu Ltd | Professional & scientific | 2025 |
| M & a Europe Ltd | Hospitality | 2016 |
| M & a HAQ Management Limited | Construction | 2018 |
| M & a Interlocking Services Limited | Professional & scientific | 2018 |
| M & a Investments London Ltd | Real estate | 2020 |
| M & a Tours Limited | Administrative & support | 2025 |
| M & AM Ltd | Professional & scientific | 2018 |
| M & B Construction Inc Limited | Construction | 2019 |
| M & C Hair Studio Ltd | Other services | 2021 |
| M & D Auto Services Limited | Water & waste | 2017 |
| M & E Translogi Ltd | Transport & logistics | 2022 |
| M & F Construct Ltd | Construction | 2016 |
| M & H Care Ltd | Health & social care | 2007 |
| M & H Charlton Ltd | Other services | 2011 |
| M & L Maintenance Limited | Construction | 2017 |
| M & M Auto Services Ashford Ltd. | Real estate | 2017 |
| M & M Commercial Finance Ltd | Financial services | 2017 |
| M & M Financial Services Ltd | Financial services | 2003 |
| M & M General Insurance Services Limited | Financial services | 2006 |
| M & M Leisure Imports Ltd | Wholesale & retail | 2022 |
| M & M Logicsoft Ltd | Extraterritorial | 2007 |
| M & N (Care Homes) Ltd | Financial services | 2006 |
| M & N Builders & Developers Ltd | Construction | 2009 |
| M & N Builders Properties 2 Ltd | Real estate | 2018 |
| M & N Builders Properties 3 Ltd | Real estate | 2019 |
| M & N Builders Properties Ltd | Real estate | 2016 |
| M & S (UK) Properties Limited | Real estate | 2006 |
| M & S Investment Business Ltd | Administrative & support | 2011 |
| M & T Wholesale Ltd | Wholesale & retail | 2003 |
| M 1090 Limited | Real estate | 2013 |
| M 3 Investment Ltd | Real estate | 2018 |
| M a S Retailers Ltd | Wholesale & retail | 2025 |
| M and a Valeting Ltd | Administrative & support | 2025 |
| M and M Hair Studio 2 Limited | Other services | 2024 |
| M Auto Trader Ltd | Transport & logistics | 2022 |
| M B Food and Beverages Limited | Wholesale & retail | 2022 |
| M Builders Limited | Professional & scientific | 2014 |
| M C Consulting (UK) Limited | Other services | 2013 |
| M G Stephens Investments Ltd. | Professional & scientific | 2000 |
| M G Wyburn Consultancy Ltd | Professional & scientific | 2021 |
| M Glass Ltd | Wholesale & retail | 2018 |
| M Holman Property Advisory Limited | Households | 2020 |
| M J Fashion Ltd | Wholesale & retail | 2020 |
| M J Foods & Wines Ltd | Wholesale & retail | 2018 |
| M J Golz & Co Ltd | Professional & scientific | 2020 |
| M J J Contractors (Ruislip) Limited | Administrative & support | 2019 |
| M K Comm Limited | Construction | 2016 |
| M K H Laminate Ltd | Construction | 2024 |
| M Kane Building Services Ltd | Construction | 2018 |
| M M Books Limited | Administrative & support | 2008 |
| M M S Contracts (London) Limited | Construction | 2011 |
| M Mullins Ltd | Construction | 2010 |
| M N House Ltd | Construction | 2015 |
| M N S Holdings London Ltd | Professional & scientific | 2016 |
| M P Alarm & Cctv Limited | Information & communication | 2018 |
| M P Alliance Ltd | Wholesale & retail | 2023 |
| M P C Fabrication Limited | Manufacturing | 2002 |
| M Patel Consulting Ltd | Professional & scientific | 2013 |
| M Patel Medical Services Ltd | Health & social care | 2013 |
| M R J (UK) Limited | Wholesale & retail | 2014 |
| M Real Estate Investments Ltd | Real estate | 2026 |
| M S Food & Wine Limited | Wholesale & retail | 1999 |
| M S Group First UK Limited | Real estate | 2025 |
| M S Painting Limited | Construction | 2020 |
| M Sheehan,Carpentry & Joinery Limited | Construction | 2000 |
| M Star Property Solutions Ltd | Construction | 2022 |
| M V T Properties Ltd | Real estate | 2021 |
| M Wholesale Limited | Wholesale & retail | 2019 |
| M X Construction Limited | Construction | 2014 |
| M&C Construction Ltd | Construction | 2020 |
| M&E Construction (Harwich) Ltd | Construction | 2022 |