| Lexaria Limited | Administrative & support | 2024 |
| Lgmb Consultancy Limited | Real estate | 2016 |
| LGS Yorkshire Construction Operations Ltd | Construction | 2021 |
| LGV Auto Pass Ltd | Other services | 2017 |
| Lifeboat Community Project | Information & communication | 2010 |
| Lifeplanning Solutions Limited | Administrative & support | 1998 |
| Lifetime Financial Solutions (Yorkshire) Ltd | Financial services | 2009 |
| Lime Tree Clothing Ltd | Extraterritorial | 2025 |
| Linkardrian Limited | Real estate | 2021 |
| Lithium Studios Ltd | Professional & scientific | 2004 |
| Little and Shooting Stars Ltd | Health & social care | 2015 |
| Littletown Football Club Limited | Arts & recreation | 2019 |
| LJB Joinery Ltd | Manufacturing | 2025 |
| LMK Electrical Services Ltd | Construction | 2019 |
| LMK Healthcare Provision Ltd | Health & social care | 2012 |
| Lomas Fp&A Services Ltd | Professional & scientific | 2020 |
| Longhorn Electrical Limited | Construction | 2019 |
| Looks FAB Limited | Health & social care | 2025 |
| Lord Family Holdings Limited | Financial services | 2026 |
| Love and Cherish Bridal Boutique Ltd | Wholesale & retail | 2025 |
| Love Yorkshire Retreats Limited | Real estate | 2025 |
| LTH Plumbing & Heating (Yorkshire) Ltd | Construction | 2024 |
| LUM Aesthetics Ltd | Other services | 2026 |
| Luminmediagroup Ltd | Professional & scientific | 2025 |
| LUX Resin Ltd | Wholesale & retail | 2024 |
| Luxurious Look Ltd | Wholesale & retail | 2020 |
| Luxury Coastal Escapes Limited | Hospitality | 2025 |
| LW Electrical (Yorkshire) Ltd | Construction | 2024 |
| Lwrcouriers Limited | Transport & logistics | 2026 |
| Lymani Properties Ltd | Real estate | 2022 |
| Lymani Transport Services Ltd | Transport & logistics | 2025 |
| Lynn UK Motors Ltd | Wholesale & retail | 2023 |
| M & J Printed Products Ltd | Manufacturing | 2013 |
| M & T Worldwide Limited | Hospitality | 2023 |
| M J Gillen Ltd | Health & social care | 2018 |
| M.A.R Courier Services Ltd | Transport & logistics | 2018 |
| M1 Interiors Limited | Construction | 2023 |
| M6 Coaching & Performance Limited | Arts & recreation | 2026 |
| Machenair Limited | Construction | 1987 |
| Machenair Steel Fabrications Limited | Extraterritorial | 2008 |
| Madison C Ltd | Real estate | 2015 |
| Malcolm Pitchforth Delivery Ltd | Transport & logistics | 2026 |
| MAP Ventilation Limited | Manufacturing | 1986 |
| Maple Controls Limited | Construction | 2003 |
| Maple Controls Systems Limited | Information & communication | 2016 |
| Maple Electrical Supplies (Ossett) Limited | Wholesale & retail | 2012 |
| Mark Reynolds Consulting Limited | Professional & scientific | 2013 |
| Mark Smithson Transport (Holdings) Limited | Financial services | 2021 |
| Mark Smithson Transport Ltd | Transport & logistics | 2014 |
| Marketlabco Ltd | Professional & scientific | 2026 |
| Marshalls Direct Ltd | Wholesale & retail | 2017 |
| Marstane Accounts & Consultants Limited | Professional & scientific | 2025 |
| Mastercraft Beds Limited | Manufacturing | 2012 |
| Masters Cricket CIC | Arts & recreation | 2023 |
| Matt Nicholls Photography Ltd | Professional & scientific | 2017 |
| Matthew John Fusco Ltd | Extraterritorial | 2025 |
| Matthew Stokes P&H Limited | Construction | 2012 |
| Maypole Enterprises Ltd | Hospitality | 2025 |
| MDM Plastering Limited | Construction | 2014 |
| MED International Limited | Extraterritorial | 2004 |
| Medley's Childminding Limited | Education | 2013 |
| Mehzu Style Limited | Manufacturing | 2024 |
| Melita Commercial Properties Limited | Real estate | 2013 |
| Mellor Solutions Ltd | Wholesale & retail | 2025 |
| Melt Dessert Bar Ltd. | Hospitality | 2024 |
| Mentoring Minds Ltd | Education | 2025 |
| Merry City Design Ltd | Professional & scientific | 2024 |
| Methley Bridge Commercials Limited | Wholesale & retail | 2012 |
| Metis Capital Partners Ltd | Administrative & support | 2020 |
| Metis Consultancy Services Ltd | Administrative & support | 2019 |
| MH Computers Ltd | Information & communication | 2015 |
| Michael Croisdale Limited | Construction | 2022 |
| Michael Fell Ltd | Extraterritorial | 2022 |
| Michael Gara Limited | Professional & scientific | 2017 |
| Mill House Holdings Yorkshire Limited | Households | 2022 |
| Miller Court Management Limited | Real estate | 1995 |
| Mirraport Ltd | Real estate | 2025 |
| Misk Properties Limited | Real estate | 2019 |
| MJL Law Limited | Professional & scientific | 2015 |
| Mkhp Foods Ltd | Hospitality | 2025 |
| Mobile Shotblasting Ltd | Construction | 2018 |
| Mockba Modular Group Ltd | Manufacturing | 2025 |
| Monaghan Planck Limited | Wholesale & retail | 2011 |
| Mooncrate Studios Ltd | Information & communication | 2026 |
| Moorgate Print Products Ltd | Manufacturing | 2020 |
| MOT Property Limited | Real estate | 2020 |
| Move on Legal Services Ltd | Professional & scientific | 2020 |
| MPWSOLUTIONS24 Ltd | Manufacturing | 2025 |
| MRD OSS Ltd | Hospitality | 2026 |
| Mudana Healthcare Ltd | Health & social care | 2021 |
| Mushroom Dispensary Ltd | Extraterritorial | 2025 |
| Music 4 Memories Ltd | Wholesale & retail | 2024 |
| MW Actuaries Limited | Financial services | 2006 |
| My Renewable Energy Limited | Construction | 2019 |
| MYK Autos Ltd | Wholesale & retail | 2026 |
| Myrtle Grove Properties Ltd | Real estate | 2023 |
| Mysing Hold Co Limited | Financial services | 2020 |
| N B Electrical Limited | Wholesale & retail | 2006 |
| N S Welding Limited | Construction | 2004 |
| Nails 17 Limited | Other services | 2003 |