| Link Electrical Solutions Ltd | Construction | 2019 |
| Little Ducks - Hemingbrough Ltd | Health & social care | 2024 |
| Little Ducks Nursery-North Duffield Ltd | Education | 2021 |
| Little Legends Childminding Ltd | Education | 2023 |
| Livepa Networks Ltd | Information & communication | 2013 |
| LJF Group Holdings Ltd | Financial services | 2026 |
| LM Financial Services Limited | Financial services | 2025 |
| Lodge Farm Services Ltd | Wholesale & retail | 2023 |
| Loftsome Bridge Hotel of Loftsome Bridge Holdings Limited | Hospitality | 2018 |
| Lollipop Lane Ltd | Education | 2022 |
| Lordship Construction Limited | Construction | 2013 |
| Lordship MLM Ltd | Extraterritorial | 2017 |
| Loud Noises Brass Limited | Arts & recreation | 2022 |
| Love of My Life Productions Limited | Information & communication | 2014 |
| Lovely Jubbly Limited | Hospitality | 2012 |
| Loxodromic Systems Limited | Information & communication | 2025 |
| Loyal Cerise Property & Developments Limited | Construction | 2003 |
| LPM Healthcare Ltd | Health & social care | 2024 |
| LR Decor Ltd | Construction | 2025 |
| LR Joinery & Carpentry Ltd | Construction | 2015 |
| LS25 Bookkeeping Ltd | Professional & scientific | 2024 |
| LSC Agri Ltd | Agriculture & fishing | 2019 |
| LT Roofing & Cladding Ltd | Construction | 2022 |
| Lucy's Pet Boutique and Dog Groomers Ltd | Other services | 2023 |
| Lukasz Dabrowski Ltd | Transport & logistics | 2014 |
| Luke Ritchards Ltd | Professional & scientific | 2025 |
| Lune's Autos Limited | Wholesale & retail | 2025 |
| LW Motor Vehicle Services Limited | Wholesale & retail | 2022 |
| Lyndon Poskitt Racing Limited | Wholesale & retail | 2019 |
| M & B Building and Joinery Limited | Construction | 2025 |
| M & K Property Services (UK) Limited | Real estate | 2011 |
| M & M Contracting Ltd | Administrative & support | 2024 |
| M & M Mortgage Solutions Limited | Financial services | 2012 |
| M & M Plumbing Heating and Mechanical Services Limited | Construction | 2004 |
| M & R Aluminium Installation Limited | Construction | 2003 |
| M a Property Consultants Ltd | Real estate | 2023 |
| M F Ellis Limited | Hospitality | 2014 |
| M J J Solutions Ltd | Professional & scientific | 2022 |
| M Rudd Consultancy Ltd | Education | 2025 |
| M&M Audio Hire Ltd | Wholesale & retail | 2023 |
| M&M Car Services Limited | Wholesale & retail | 2011 |
| MA Projects Ltd | Construction | 2017 |
| MAB Consulting Ltd | Professional & scientific | 2025 |
| Macaltec Technical Services Ltd | Professional & scientific | 2024 |
| Maccamoo Ltd | Professional & scientific | 2021 |
| Mackinder Farms Holiday Accommodation (North Yorkshire) Limited | Hospitality | 2026 |
| Mackinder Farms Holiday Accommodation LLP | | 2012 |
| Mactraffic Limited | Construction | 2025 |
| Madison&Blades Ltd | Hospitality | 2025 |
| Magic Sun Ltd | Other services | 2024 |
| Magnate Transportation Consultancy Services Ltd | Professional & scientific | 2026 |
| Maha PVT Ltd | Wholesale & retail | 2023 |
| Maier Trans Ltd | Transport & logistics | 2016 |
| Maiku Ltd | Information & communication | 2008 |
| Majestic Garage (Goole) Ltd | Wholesale & retail | 2011 |
| MAK Contracting Ltd | Professional & scientific | 2019 |
| Malc Collins Mini Coaches Limited | Transport & logistics | 2004 |
| Malec SM Ltd | Transport & logistics | 2014 |
| Mandj Yorkshire Ltd | Professional & scientific | 2023 |
| Mango Monkey Marketing Limited | Administrative & support | 2026 |
| Mansfield House Hotel Ltd | Hospitality | 2017 |
| Maple Events Ltd | Hospitality | 2026 |
| Marisoul Studio Ltd | Information & communication | 2024 |
| Marley Homes Ltd | Construction | 2021 |
| Marow Limited | Professional & scientific | 2015 |
| Marroni Tax Limited | Professional & scientific | 2021 |
| Marshall Properties 2025 Ltd | Construction | 2025 |
| Marshalvane Limited | Agriculture & fishing | 1980 |
| Martins Services Ltd | Transport & logistics | 2017 |
| Martinswood Ltd | Manufacturing | 2010 |
| Masc-It Ltd | Information & communication | 2012 |
| Masflow Limited | Professional & scientific | 2026 |
| Matland (UK) Ltd | Construction | 2025 |
| Mattgray Hospitality Limited | Administrative & support | 2019 |
| Matthew Byrne Enterprises Ltd | Financial services | 2021 |
| MB Energy Services Ltd | Mining & quarrying | 2023 |
| MB Tax Solutions Limited | Professional & scientific | 2010 |
| MBC Express Ltd | Transport & logistics | 2021 |
| MCN Brown Limited | Construction | 2012 |
| Mdrj Limited | Professional & scientific | 2022 |
| MEB Electrical York Ltd | Construction | 2024 |
| Melia Automation Ltd | Professional & scientific | 2026 |
| Melville Place Limited | Real estate | 2010 |
| Mendedge Ltd | Wholesale & retail | 2025 |
| Menomovement Limited | Education | 2024 |
| Mertec Engineering Services Limited | Manufacturing | 2019 |
| Metanoia Film Limited | Information & communication | 2015 |
| MF Accountancy Solutions Ltd | Professional & scientific | 2025 |
| MFM Logistics Ltd | Transport & logistics | 2020 |
| MH Projects Yorkshire Ltd | Construction | 2026 |
| MI Images Limited | Professional & scientific | 2009 |
| Miami Tanning & Beauty Ltd | Other services | 2026 |
| Michael Stewart Limited | Wholesale & retail | 2011 |
| Michael Walsh (Plasterers) Limited | Construction | 1977 |
| Mick Wilson Construction Limited | Professional & scientific | 2010 |
| Mickley Hydro Scheme Limited | Energy | 2008 |
| Micton Solution Limited | Wholesale & retail | 2023 |
| Midas Aggregates Ltd | Wholesale & retail | 2024 |
| Midgel Engineering Ltd | Professional & scientific | 2020 |
| Midnight Dreamery Ltd | Manufacturing | 2025 |