| L.S.Atkinson Ltd | Construction | 2022 |
| LAB in the Garage Brewing Ltd | Manufacturing | 2024 |
| Lagentium Insurance Brokers Ltd | Financial services | 2017 |
| Lagentium Ventures Limited | Real estate | 2025 |
| Lagentium.Studio Limited | Professional & scientific | 2024 |
| Lahrichi's Barbers Limited | Other services | 2023 |
| LAL13 Ltd | Real estate | 2022 |
| LAL14 Ltd | Real estate | 2022 |
| LAL16 Ltd | Administrative & support | 2023 |
| Lamberts Engineering Ltd | Professional & scientific | 2020 |
| Lambson Innovate Limited | Manufacturing | 1966 |
| Laminated Products Limited | Manufacturing | 1989 |
| Lancaster Aggregates & Grab Ltd | Wholesale & retail | 2021 |
| Lannds Property Ltd | Real estate | 2021 |
| LAT Care Company Limited | Health & social care | 2022 |
| Lawrence and Foster Limited | Manufacturing | 1994 |
| Lawrie Project Management Ltd | Professional & scientific | 2024 |
| LC Enterprising Limited | Construction | 2019 |
| Ldlife Ltd | Health & social care | 2023 |
| Leaseable Estates Limited | Construction | 2022 |
| LEE Johnston Signage Limited | Construction | 2012 |
| Lee&Alie Healthcare Limited | Health & social care | 2019 |
| Leeds Driver Hire Limited | Transport & logistics | 2024 |
| Leeds Faiths Forum | Other services | 2005 |
| Leger Court Doncaster Limited | Households | 2025 |
| Legion Solutions Ltd | Administrative & support | 2024 |
| Leicestershire Energy Partnerships Limited | Professional & scientific | 2020 |
| Lemac NO.1 Limited | Professional & scientific | 2009 |
| Letric Limited | Information & communication | 2019 |
| Leyland Road Hand Car Wash Ltd | Other services | 2017 |
| Leylands Workshop Ltd | Other services | 2015 |
| Libp Cell 6 Speke Management Company Limited | Real estate | 2006 |
| Lily's Properties Limited | Real estate | 2023 |
| Linbell Properties Ltd | Real estate | 2022 |
| Lincolnshire Energy Partnerships Limited | Professional & scientific | 2020 |
| Lindsays Cafe Limited | Hospitality | 2015 |
| Lipcsei Ltd | Transport & logistics | 2016 |
| Liquid Retail Limited | Administrative & support | 2016 |
| Lisa Star Nails & Beauty (Knottingley) Limited | Other services | 2020 |
| Live Oak Healthcare Services Limited | Health & social care | 2023 |
| Living of Costs Ltd | Manufacturing | 2024 |
| LJ & Keat Homes Limited | Construction | 2020 |
| LJ and Keat Letting Ltd | Real estate | 2017 |
| LJ Logistics Services Ltd | Transport & logistics | 2025 |
| Llewellyn Rigging & Lifting Ltd | Construction | 2024 |
| Lloyd Kendrick Ltd | Information & communication | 2017 |
| LM Transport (North) Limited | Transport & logistics | 2020 |
| Lnleisure Ltd | Hospitality | 2025 |
| Local Energy Partnerships Limited | Energy | 2018 |
| Local Store Airdale Limited | Wholesale & retail | 2024 |
| Lock Lane Electrical Limited | Construction | 2023 |
| Logic Solar Ltd | Construction | 2022 |
| Logistifix Limited | Professional & scientific | 2017 |
| London Energy Partnership Limited | Professional & scientific | 2020 |
| Longrose Greentown Inkersall LLP | | 2023 |
| Look Sharp Hairsalon Ltd | Other services | 2024 |
| LP Trading Management Ltd | Wholesale & retail | 2023 |
| LR Cards & Collectables Ltd | Wholesale & retail | 2021 |
| LR Event Management (UK) Ltd | Administrative & support | 2023 |
| LR Strategy & Systems Ltd | Information & communication | 2025 |
| LS Tippers Ltd | Transport & logistics | 2019 |
| LST Services Ltd | Wholesale & retail | 2021 |
| Lucas Approved Ltd | Wholesale & retail | 2024 |
| Lucas IT Consultants Ltd | Information & communication | 2026 |
| Ludum Ltd | Arts & recreation | 2019 |
| Lukstar Commercial Ltd | Wholesale & retail | 2024 |
| Lumb Dogs UK Ltd | Hospitality | 2023 |
| Lumos AJM Limited | Professional & scientific | 2025 |
| Luxe and Dough Limited | Manufacturing | 2025 |
| LW Roofing Building Ltd | Construction | 2024 |
| M a W Electrical Services (Yorkshire) Ltd | Construction | 2020 |
| M a W Housing (Yorkshire) Ltd | Real estate | 2025 |
| M I Foods (Castleford) Ltd | Hospitality | 2024 |
| M W Handling Ltd | Wholesale & retail | 2018 |
| M&H Takeaway Ltd | Hospitality | 2025 |
| M&N Utilities Limited | Construction | 2016 |
| M&P Fire Protection Ltd | Administrative & support | 2010 |
| M.M. Industrial Roofing Ltd | Construction | 2021 |
| M.R. Management Services Ltd | Construction | 2018 |
| Made by Urban Limited | Professional & scientific | 2022 |
| Made to Sparkle Ltd | Administrative & support | 2016 |
| MAG Media Limited | Information & communication | 2000 |
| Magic WOK 8 Limited | Hospitality | 2023 |
| Magister Properties Limited | Real estate | 2026 |
| Mags Healthcare Ltd | Health & social care | 2021 |
| Majestic JET Solutions Ltd | Administrative & support | 2025 |
| Makethisdigital Limited | Wholesale & retail | 2021 |
| Malita Ltd | Wholesale & retail | 2023 |
| Mama Takeaway Ltd | Hospitality | 2025 |
| Manor Motors Car Sales Limited | Wholesale & retail | 2016 |
| Mapplewell Homes Limited | Real estate | 2019 |
| Mar-Pol Ltd | Transport & logistics | 2012 |
| March Lettings Ltd | Real estate | 2015 |
| Marcus Rupert Wolf Ltd | Construction | 2018 |
| Marina Consultants Ltd | Health & social care | 2015 |
| Marina Lodges Ltd | Real estate | 2021 |
| Marisa Spa Limited | Health & social care | 2022 |
| Marius Bondoc Ltd | Transport & logistics | 2025 |
| Marvtek Engineering Services Ltd | Professional & scientific | 2023 |
| MAS Services (UK) Limited | Professional & scientific | 2013 |