| Logan Denvers Enterprises Limited | Real estate | 2011 |
| London Zeera Ltd | Manufacturing | 2025 |
| Lotus Care and Support Services Limited | Health & social care | 2021 |
| Lotus Chinese Meals Limited | Hospitality | 2020 |
| Louby Lou's Storytelling Ltd | Arts & recreation | 2022 |
| Lovara Limited | Real estate | 2025 |
| Lowe Classics Ltd | Wholesale & retail | 2022 |
| Lowe Moto Ltd | Wholesale & retail | 2024 |
| LSL Hire and Sales Ltd | Manufacturing | 2018 |
| LTM Investing Ltd | Real estate | 2023 |
| Ludlow Brook Ltd | Wholesale & retail | 2025 |
| Luke Shephard Funeral Directors Limited | Professional & scientific | 2023 |
| Luke Windsor Limited | Professional & scientific | 2018 |
| Luma Living Group Limited | Health & social care | 2025 |
| Lumensa Ltd | Wholesale & retail | 2018 |
| Lumislab Ltd | Wholesale & retail | 2025 |
| Lumsden Dyers Ltd | Wholesale & retail | 2025 |
| Lush Wigs Ltd | Wholesale & retail | 2015 |
| Luxurious Beauty Limited | Other services | 2020 |
| LVC Construction Ltd | Construction | 2022 |
| M and KI Properties Ltd | Real estate | 2024 |
| M B Evans Limited | Manufacturing | 1999 |
| M H Middle Plumbing and Heating Ltd | Construction | 2003 |
| M J Pearce Building and Landscaping Limited | Construction | 2017 |
| M R Barnby Ltd | Construction | 2014 |
| M&H Estates Ltd | Real estate | 2016 |
| M&H Trading Ltd | Wholesale & retail | 2014 |
| M&R Motorcycle Tours LLP | | 2023 |
| M&S Commercial Property Limited | Real estate | 2024 |
| M&Y Group Ltd | Wholesale & retail | 2022 |
| Maben Property Ltd | Real estate | 2026 |
| Maben Vehicle Hire Ltd | Administrative & support | 2012 |
| Maben Vehicle Sales Ltd | Wholesale & retail | 2021 |
| Mabpropertyinvestmentservices Ltd | Real estate | 2026 |
| Machen Store Ltd | Wholesale & retail | 2023 |
| Madame Fromage Limited | Manufacturing | 2021 |
| Maddon Generators Limited | Manufacturing | 2003 |
| Made of Stone Fitness Ltd | Other services | 2020 |
| Made to Measure Garden Buildings Ltd | Manufacturing | 2015 |
| Magdalene Mina Ltd | Wholesale & retail | 2025 |
| Maha (Ponty) Ltd | Hospitality | 2020 |
| MAJ Data Ltd | Construction | 2026 |
| Malachi Harold Ltd | Wholesale & retail | 2024 |
| Malibabi Ltd | Wholesale & retail | 2017 |
| Mamau Ffit Ltd | Arts & recreation | 2026 |
| Mambiea Care Ltd | Health & social care | 2025 |
| Mamhilad Park Estate Limited | Extraterritorial | 2016 |
| Mana Trailers and Towing Ltd | Manufacturing | 2020 |
| Manston Hest Ltd | Wholesale & retail | 2025 |
| Mantis Services Ltd | Manufacturing | 2026 |
| Marcus Warner Coaching Ltd | Arts & recreation | 2021 |
| Marshall & Hicks Print Limited | Manufacturing | 2015 |
| Martin Norman Building Services Limited | Information & communication | 2014 |
| Martin the Local Plumber Ltd | Construction | 2022 |
| Mason Jones Ltd | Professional & scientific | 2021 |
| Matt Rogers Trading Ltd | Real estate | 2024 |
| Maxblu Air Conditioning Ltd | Construction | 2020 |
| Maya's Pebbles Ltd | Real estate | 2025 |
| MB Design Architectural Services Ltd | Professional & scientific | 2025 |
| MDW Auto Limited | Wholesale & retail | 2014 |
| Meadow Grove Llangrove Limited | Households | 2025 |
| Meadow Walk Management Limited | Real estate | 2010 |
| Meadowell Therapies Ltd | Health & social care | 2026 |
| Meadway Rise Ltd | Wholesale & retail | 2025 |
| Medcross Limited | Manufacturing | 1981 |
| Medea H Ltd | Arts & recreation | 2022 |
| Medicare for ALL Ltd | Health & social care | 2023 |
| Medina Sands Ltd | Wholesale & retail | 2025 |
| Medrus Engineering Ltd | Manufacturing | 2009 |
| Megan Turner Cleaning Ltd | Administrative & support | 2025 |
| Melbourne Bishop Ltd | Wholesale & retail | 2025 |
| Melton Ludlow Ltd | Wholesale & retail | 2025 |
| Merevale Hobs Ltd | Wholesale & retail | 2025 |
| Merton FOX Limited | Administrative & support | 2024 |
| Methuen & Gicquel Limited | Real estate | 2013 |
| Metsolar Limited | Manufacturing | 2024 |
| MH Limitless Limited | Professional & scientific | 2025 |
| Mhfa Wales Ltd | Education | 2010 |
| MI Blinds Limited | Wholesale & retail | 2019 |
| Michael Gary Hancock Limited | Extraterritorial | 2025 |
| Michele Zerbino Ltd | Professional & scientific | 2025 |
| Mido Plant Services Ltd | Agriculture & fishing | 2010 |
| Midway Transitional Solutions Ltd | Health & social care | 2015 |
| Miliwn Limited | Real estate | 2024 |
| Mill Hospitality Ltd | Hospitality | 2025 |
| Mill Lane Childcare Ltd | Health & social care | 2025 |
| Millbrook Almond Ltd | Wholesale & retail | 2025 |
| Millhill Elms Ltd | Wholesale & retail | 2025 |
| Milverton Maycliffe Ltd | Wholesale & retail | 2025 |
| Mint Construction & Maintenance Ltd | Construction | 2024 |
| Mint Property Development Ltd | Real estate | 2026 |
| Mint Solar Ltd | Professional & scientific | 2023 |
| MJ Dental Services Ltd | Health & social care | 2012 |
| Mjib Accounting Ltd | Professional & scientific | 2022 |
| MLC Group Ltd | Financial services | 2025 |
| MLT Advisory Ltd | Professional & scientific | 2025 |
| MLW Utilities Ltd | Construction | 2026 |
| Model-K Limited | Transport & logistics | 2015 |
| Mogul Mechanical Engineering Ltd | Professional & scientific | 2020 |
| Mondale Fane Ltd | Wholesale & retail | 2025 |