| Live Naturally CIC | Wholesale & retail | 2014 |
| Live Side Ways Limited | Manufacturing | 2012 |
| Ljci Hospitality Ltd | Hospitality | 2019 |
| LJT Electrical Services Ltd | Construction | 2018 |
| LK Davies Limited | Professional & scientific | 2009 |
| Llanfabon Futures Ltd | Real estate | 2021 |
| LLM Design Limited | Arts & recreation | 2022 |
| Llum Ltd | Information & communication | 2024 |
| LM Support Services Southwest Limited | Health & social care | 2016 |
| Lock & Ledger Ltd | Professional & scientific | 2025 |
| Lockhill Briars Company Limited | Agriculture & fishing | 2022 |
| Lockhill Estates Limited | Real estate | 2021 |
| Lockhill Holdings Limited | Real estate | 2023 |
| Lockhill Pipers Limited | Real estate | 2025 |
| Locks on the Levels Ltd | Other services | 2022 |
| Lodge Farming Limited | Agriculture & fishing | 2015 |
| Loft Living Conversions Limited | Administrative & support | 2014 |
| London Digital Movie and TV Studios Estates Ltd | Information & communication | 2019 |
| London Digital Movie and TV Studios Ltd | Information & communication | 2017 |
| Long Acre Land Limited | Financial services | 2007 |
| Long Industries Limited | Wholesale & retail | 2019 |
| Lonsdale Plant Nursery Ltd | Wholesale & retail | 2021 |
| Lorimer Construction Management Ltd | Construction | 2024 |
| Lotus Health and Beauty Therapy Ltd | Other services | 2022 |
| Love Community CIC | Administrative & support | 2021 |
| Love-Yes Limited | Wholesale & retail | 2025 |
| Lovely Bubbles Ltd | Manufacturing | 2020 |
| Lower Huntham Ltd | Construction | 2025 |
| Lower Rodway Ltd | Administrative & support | 2025 |
| LP Autism Consultancy Ltd | Health & social care | 2022 |
| LR Respiratory Training & Consultancy Limited | Public administration | 2023 |
| LRA Energy Solutions Ltd | Manufacturing | 2022 |
| LSB Accountancy Services Limited | Professional & scientific | 2023 |
| Lucian Express Delivery Ltd | Administrative & support | 2017 |
| Luke & Stan Travel Ltd | Administrative & support | 2021 |
| Luke Richards Design Limited | Professional & scientific | 2014 |
| Lumber Construction Limited | Administrative & support | 2011 |
| Lumiere Property Group Limited | Real estate | 2025 |
| Lumley Engineering Limited | Professional & scientific | 2006 |
| Luna Group Investments Limited | Real estate | 2024 |
| LW Surveyors Ltd | Construction | 2023 |
| Lydeard Farm Bush Camp and Lodges LLP | | 2023 |
| Lynnes Legacy Community Crafts CIC | Education | 2025 |
| M & a Brooks Ltd | Hospitality | 2020 |
| M & H Event Catering Ltd | Hospitality | 2024 |
| M & L David the Halfway House Limited | Hospitality | 2022 |
| M a Taylor Transport Ltd | Transport & logistics | 2019 |
| M Allison Consulting Limited | Information & communication | 2016 |
| M D Decorating Limited | Construction | 2019 |
| M J Parsons & Sons Ltd | Construction | 2020 |
| M M Mansions Limited | Real estate | 2001 |
| M P Plastering Limited | Administrative & support | 2010 |
| M Rousell Carpentry & Property Maintenance Limited | Construction | 2021 |
| M Tanasa Ltd | Construction | 2015 |
| M Tech (SW) Ltd | Construction | 2013 |
| M W Coombes Limited | Agriculture & fishing | 2012 |
| M&C DUO Creations Ltd | Hospitality | 2023 |
| M&M 5G Limited | Information & communication | 2018 |
| M&R Best 4 Cleaning Limited | Construction | 2019 |
| M&S Building and Property Services Ltd | Construction | 2025 |
| M-Cnc Limited | Manufacturing | 2013 |
| M-Edge Properties Investment Ltd | Real estate | 2026 |
| M.Brown Ltd | Other services | 2017 |
| M.E. Ring Consulting Ltd | Professional & scientific | 2022 |
| M.E.M Property Limited | Real estate | 2024 |
| M.I. Beauty Limited | Other services | 2024 |
| M.K Scaffolding Limited | Construction | 2016 |
| M.M Logistics Consultancy Limited | Administrative & support | 2009 |
| M.May Electrical Ltd | Construction | 2025 |
| M5 Textiles Holding Limited | Financial services | 2019 |
| Macca & Macca Ltd | Wholesale & retail | 2022 |
| Macready G Limited | Wholesale & retail | 2017 |
| Macready Properties Ltd | Real estate | 2025 |
| Macsi Digital Limited | Information & communication | 2018 |
| Macsi Ltd | Administrative & support | 2012 |
| MAD Parcel Grind Limited | Transport & logistics | 2021 |
| Madadore Designs Ltd | Manufacturing | 2019 |
| Made by Bees - Cox’S Farm Honey Co. Ltd | Wholesale & retail | 2021 |
| Made in the South West Limited | Other services | 2024 |
| Madeira Lodge Limited | Construction | 2020 |
| Maestro's Pizza Limited | Hospitality | 2021 |
| Magneta Construction Ltd | Construction | 2025 |
| Maison Monnaie Ltd. | Wholesale & retail | 2024 |
| Majenta Audio Visual Limited | Construction | 2006 |
| Make IT Smooth Limited | Construction | 2026 |
| Makemoneywork Ltd | Real estate | 2026 |
| Makepeace Associates Ltd | Professional & scientific | 2014 |
| Maliwans Limited | Extraterritorial | 2016 |
| Managed Document Solutions Limited | Administrative & support | 2012 |
| Mandaba Investments Limited | Health & social care | 2025 |
| Mane (Somerset) Limited | Other services | 2020 |
| Maneki Sushi Limited | Hospitality | 2026 |
| Mangrai Limited | Real estate | 2020 |
| Manifest -ER Sono Ltd | Health & social care | 2024 |
| Manor Court (Cossington) Management Company Limited | Hospitality | 2002 |
| Manor Court Management (Weston-Super-Mare) Limited | Real estate | 2008 |
| Mansfield Property Management Limited | Real estate | 2025 |
| Manucomm Recruitment Ltd | Administrative & support | 2011 |
| Manufax Limited | Professional & scientific | 1993 |
| Maple Court (East Bower) Management Company Limited | Households | 1989 |