| Liquid Gold Water &Co Limited | Wholesale & retail | 2024 |
| Little Lionheart Ltd | Wholesale & retail | 2018 |
| Little Lotties Limited | Education | 2012 |
| Little U’S Discovery Limited | Arts & recreation | 2022 |
| Littlesmith Property Limited | Real estate | 2021 |
| LMB Advice Limited | Professional & scientific | 2014 |
| LMB Storage Solutions Limited | Transport & logistics | 2014 |
| Locum Solutions Yorkshire Limited | Health & social care | 2014 |
| Lodge Mortgage Solutions Ltd | Financial services | 2019 |
| London Brand Impact Ltd | Professional & scientific | 2014 |
| Lost Phoenix Ltd | Transport & logistics | 2024 |
| Louise Woollard LLP | | 2013 |
| LP Decorating Limited | Construction | 2020 |
| LRA Marketing Ltd | Professional & scientific | 2015 |
| Lucas Safety Limited | Professional & scientific | 2020 |
| Lume Ltd | Hospitality | 2025 |
| Luqmarn & Co Limited | Wholesale & retail | 2024 |
| LUX Shop Fitting Limited | Construction | 2023 |
| Luxury Designer Room Interiors Limited | Wholesale & retail | 2020 |
| M & M Plumbing Limited | Construction | 2021 |
| M a C Financial Services Limited | Financial services | 2005 |
| M.A. Hayhurst Properties Ltd | Construction | 2020 |
| MA Yorkshire Ltd | Health & social care | 2018 |
| MAC Handley Properties Ltd | Extraterritorial | 2024 |
| Madmunki Ltd | Information & communication | 2012 |
| Magical Orlando Ltd | Hospitality | 2020 |
| Maid N' Heaven Ltd | Administrative & support | 2025 |
| Maid Vericlean Ltd | Administrative & support | 2025 |
| Majestic Sapphire Limited | Other services | 2020 |
| Mamil Cafe Bars Limited | Hospitality | 2020 |
| Mandate Holdings Limited | Financial services | 2018 |
| Mandate Systems Limited | Professional & scientific | 1991 |
| Manrochem Limited | Professional & scientific | 1990 |
| Manzana Contracts (UK) Limited | Manufacturing | 2011 |
| Manzana Holdings Limited | Financial services | 2021 |
| Marcinparquet Limited | Manufacturing | 2025 |
| Mark Peters Racing Ltd | Arts & recreation | 2026 |
| Markis Auto Sale Ltd | Wholesale & retail | 2025 |
| Martin Dyson Homes Limited | Construction | 2015 |
| Marzano Bridge Ltd | Hospitality | 2024 |
| Marzano Ltd | Hospitality | 2017 |
| Maverick Education Technologies Ltd | Information & communication | 2024 |
| Maxim Property Investments Limited | Financial services | 2021 |
| Mazurappliances Ltd | Manufacturing | 2024 |
| MB Services (Northern) Limited | Professional & scientific | 2021 |
| MBE Brighouse Limited | Hospitality | 2023 |
| MBE Wakefield Ltd | Hospitality | 2025 |
| Mbpm Limited | Professional & scientific | 2024 |
| MC Childcare T/As Strawberries Nursery Ltd | Education | 2024 |
| Mcfield Residential Lettings & Property Management Limited | Real estate | 2019 |
| Medical Disposables Ltd | Health & social care | 2016 |
| Meds OPT Ltd | Professional & scientific | 2024 |
| Medstore Limited | Wholesale & retail | 2015 |
| Megapot Limited | Other services | 2020 |
| Megasuite Limited | Wholesale & retail | 2025 |
| Meidera Ltd | Transport & logistics | 2025 |
| Melbourne Raceway Limited | Arts & recreation | 2020 |
| Melissa Worth Legal Limited | Professional & scientific | 2021 |
| Mellors Wheelworks Ltd | Wholesale & retail | 2025 |
| Melody 2026 a Limited | Extraterritorial | 2026 |
| Melody AI Limited | Information & communication | 2023 |
| Mewpmart Ltd | Administrative & support | 2024 |
| Mexi Bean Express Ltd | Hospitality | 2021 |
| Mexi Bean Ltd | Hospitality | 2020 |
| Mexicano & Co (York) Limited | Hospitality | 2017 |
| Mey-Tech Limited | Manufacturing | 1999 |
| MFG 2026 Limited | Wholesale & retail | 2025 |
| MFI Carpets and Furniture Ltd | Wholesale & retail | 2024 |
| MGM Flooring Ltd | Construction | 2026 |
| MGS Global Services Limited | Wholesale & retail | 2019 |
| MGS Global Sourcing Limited | Wholesale & retail | 2020 |
| Michael Wilson & SON Limited | Construction | 2007 |
| Mighty Distribution Limited | Administrative & support | 2024 |
| Mike Barnett Valeting and Detailing Limited | Administrative & support | 2022 |
| Milano Pizza Bradford Road Ltd | Hospitality | 2025 |
| Mill Cottage Montessori School Ltd | Education | 2005 |
| Mill Royd Limited | Professional & scientific | 2022 |
| Millers Oils Limited | Manufacturing | 1914 |
| Millstone Grit Productions Ltd. | Information & communication | 2011 |
| Milo Project Consulting Limited | Professional & scientific | 2013 |
| Mind Body Goals Ltd | Manufacturing | 2021 |
| Mindoarmatter Ltd | Arts & recreation | 2022 |
| Miracle Inside Diagnostic Scan Clinic Ltd | Health & social care | 2019 |
| Miracle Inside UK (Franchise) Ltd | Other services | 2023 |
| Miracle Inside UK Ltd | Health & social care | 2015 |
| MJ Security (Brighouse) Limited | Construction | 2022 |
| MK Trading 99 Ltd | Construction | 2019 |
| MKO Trading Limited | Wholesale & retail | 2024 |
| MM Distribution Ltd | Wholesale & retail | 2021 |
| Mobile Parts UK Limited | Information & communication | 2010 |
| Mobus Fabrics Holdings Limited | Financial services | 2017 |
| Mobus Fabrics Limited | Manufacturing | 1994 |
| Modge Design Studio Limited | Arts & recreation | 2026 |
| Monarch Art Stone Limited | Construction | 2002 |
| Mont Blanc Holdings Limited | Financial services | 2019 |
| Moore Growth Limited | Professional & scientific | 2011 |
| Moto UK Limited | Wholesale & retail | 2006 |
| Motoburo Ltd | Wholesale & retail | 2019 |
| Motor Connection Ltd | Wholesale & retail | 2024 |
| MPC Carpets Ltd. | Wholesale & retail | 2022 |