| Lumley Castle Enterprises LLP | | 2023 |
| Lumley Castle Limited | Hospitality | 2023 |
| Lumley Retail Services Limited | Construction | 2023 |
| Luna Gems Ltd | Wholesale & retail | 2025 |
| Lunacosta Ltd | Professional & scientific | 2014 |
| Lunn Cars Ltd | Wholesale & retail | 2025 |
| Lunori CIC | Health & social care | 2025 |
| Lupo Properties Ltd | Real estate | 2024 |
| Lure Factors Ltd | Wholesale & retail | 2024 |
| Lusso Occasionsuk Limited | Hospitality | 2025 |
| Luxbor Ltd | Professional & scientific | 2015 |
| Luxe & Co Property Services Ltd | Manufacturing | 2023 |
| Luxe Flawless Extensions Limited | Wholesale & retail | 2025 |
| Luxe Glow Studio Limited | Other services | 2026 |
| Luxefinds Ltd | Wholesale & retail | 2025 |
| Luxmore Ltd | Information & communication | 2026 |
| Luxury Nails (AJ) Limited | Other services | 2024 |
| LVA Solutions Limited | Manufacturing | 2024 |
| LVL Removals Ltd | Transport & logistics | 2025 |
| LVR Group Ltd | Construction | 2025 |
| LW Auto Sales Ltd | Wholesale & retail | 2024 |
| LW Site Services Limited | Construction | 2019 |
| LWA Learning Limited | Education | 2009 |
| Lydia House Management Company Limited | Households | 2012 |
| Lyndhurst CHS Holdings Limited | Professional & scientific | 2015 |
| Lyndhurst Cooling & Heating Services Limited | Construction | 2005 |
| Lyndhurst Group Properties Ltd | Construction | 2024 |
| Lyndhurst Hvac Ltd | Financial services | 2024 |
| Lynnwell Limited | Administrative & support | 2025 |
| Lynskey Plant Hire Limited | Extraterritorial | 2002 |
| M & B Holdings Sportsbox Ltd | Hospitality | 2021 |
| M & E Sound Pulse Ltd | Professional & scientific | 2025 |
| M & M Contracts (Northern) Limited | Construction | 2004 |
| M & S Boxes and Packaging Ltd | Manufacturing | 2011 |
| M & Y Bargains Limited | Wholesale & retail | 2025 |
| M a Detailing and Sales Ltd | Wholesale & retail | 2025 |
| M a P Railway Solutions Ltd | Other services | 2010 |
| M Brown Trading Ltd | Wholesale & retail | 2020 |
| M D Box Limited | Construction | 2023 |
| M Darrell Limited | Financial services | 2012 |
| M Desing Ltd | Wholesale & retail | 2015 |
| M E Photography Ltd | Professional & scientific | 2023 |
| M Foster Dental Surgeon Ltd | Health & social care | 2008 |
| M G Roofing Contracts Ltd | Construction | 2018 |
| M H Catering (SY) Limited | Hospitality | 2023 |
| M Hibbert Electrical Ltd | Construction | 2018 |
| M J Downing Ltd | Agriculture & fishing | 2012 |
| M J M Toolmaking Limited | Manufacturing | 2001 |
| M J Regan Ltd | Construction | 2010 |
| M K Browns Ltd | Construction | 2019 |
| M N J Mot's Limited | Wholesale & retail | 2010 |
| M Peters Carpet & TM Services Ltd | Construction | 2020 |
| M R C H Computer Services Limited | Other services | 2015 |
| M Rhodes Grab Hire Ltd | Administrative & support | 2018 |
| M S Sports Ltd | Wholesale & retail | 2018 |
| M SAY Properties Ltd | Real estate | 2021 |
| M Schofield Plumbing and Heating Ltd | Construction | 2026 |
| M T B Properties UK Ltd | Real estate | 2022 |
| M T B Railway Consulting Ltd | Construction | 2021 |
| M T Solutions Rotherham Ltd | Transport & logistics | 2026 |
| M Tahir Optical Limited | Health & social care | 2026 |
| M U S Property Developments Limited | Construction | 2007 |
| M Wood Consulting Ltd | Professional & scientific | 2017 |
| M&B Holdings Ltd | Hospitality | 2019 |
| M&B Partitions Ltd | Construction | 2022 |
| M&D Security Systems Ltd | Administrative & support | 2015 |
| M&E Rainscreen Cladding Installations Ltd | Construction | 2024 |
| M&H Autos Ltd | Wholesale & retail | 2022 |
| M&K Fashion Ltd | Wholesale & retail | 2021 |
| M&L Commercial Ltd | Wholesale & retail | 2017 |
| M&M Full Maintenance Service Ltd | Construction | 2025 |
| M&M Kandemir Ltd | Hospitality | 2025 |
| M&M Toma Ltd | Transport & logistics | 2022 |
| M&O Telecoms Ltd | Professional & scientific | 2026 |
| M&R Erecting Ltd | Construction | 2025 |
| M&R Stanley Holdings Limited | Financial services | 2021 |
| M&Z Training and Consulting Ltd | Construction | 2025 |
| M-Ab Medloc Ltd | Health & social care | 2020 |
| M. B. Eilliot Limited | Hospitality | 2021 |
| M.A. Barratt Limited | Professional & scientific | 2009 |
| M.A.L.C.B. Ltd | Hospitality | 2017 |
| M.A.M. Management Ltd | Information & communication | 2013 |
| M.A.M. WAX Ltd | Administrative & support | 2014 |
| M.B. Heating Solutions Ltd | Construction | 2012 |
| M.B. Joinery Services Ltd | Construction | 2009 |
| M.C Joinery and Interiors Ltd | Construction | 2020 |
| M.E.P. Developments Limited | Real estate | 1999 |
| M.H Mechanic Ltd | Wholesale & retail | 2025 |
| M.I.S. Architectural Aluminium Limited | Manufacturing | 1991 |
| M.K.D Construction Ltd | | 1998 |
| M.N.Executive Travel Ltd | Transport & logistics | 2024 |
| M.R.E. Services (Bewdley) Limited | Manufacturing | 2002 |
| M.W. Lawton Plastering Ltd | Construction | 2018 |
| M1 Welfare Sanitation Services Ltd | Administrative & support | 2021 |
| M18 Bait Supplies Ltd | Wholesale & retail | 2019 |
| M2- Housing Ltd | Real estate | 2025 |
| M28 Scaffolding Solutions Ltd | Construction | 2020 |
| M2M Professional Services Limited | Construction | 2022 |
| M2N Contracts Ltd | Construction | 2020 |
| M60 Plumbing&Heating Ltd | Construction | 2020 |