| Just Community Psychology Greenwich Ltd | Health & social care | 2022 |
| Just Flowers (Seaton) Limited | Wholesale & retail | 2003 |
| K J S (Devon) Limited | Wholesale & retail | 2003 |
| Karer Ltd | Wholesale & retail | 2022 |
| Kebabshish Ltd | Hospitality | 2020 |
| Kennford Tarmacadam Ltd. | Construction | 2009 |
| Kenworthy & Arbourne Limited | Construction | 2012 |
| Keswick Court RTM Company Limited | Households | 2026 |
| Knight RPC Ltd | Real estate | 2024 |
| Knight RPD Ltd | Real estate | 2024 |
| Knight RPW Ltd | Real estate | 2025 |
| Konnect Clinical Psychology Ltd | Health & social care | 2024 |
| Kurdish Barber Seaton Ltd | Other services | 2021 |
| L. & K. Warcup (Construction) Limited | Construction | 1988 |
| Labmedics Servicing Ltd | Manufacturing | 2020 |
| Lamberts Castle Riding Club Ltd | Arts & recreation | 2023 |
| Larham Psychology Services Ltd | Health & social care | 2022 |
| Lawson Homes Limited | Real estate | 2003 |
| LB Psychological Services Limited | Education | 2023 |
| LB Removals Ltd | Transport & logistics | 2013 |
| LEE Austin Ltd | Information & communication | 2017 |
| LEE Clifford Engineering Ltd | Administrative & support | 2010 |
| Leigham Court Property Management Limited | Households | 2011 |
| Level Image Creative Design Limited | Information & communication | 2014 |
| Lewesdon Court (Maintenance) Limited | Real estate | 1970 |
| Libertaria Limited | Real estate | 2005 |
| Lichfield Road Management Company Limited | Households | 1981 |
| Lignum Lorica Ltd | Construction | 2020 |
| Livemoor Limited | Hospitality | 2017 |
| Livingston Therapy Ltd | Health & social care | 2024 |
| Locke Digital Limited | Professional & scientific | 2015 |
| Louise Mccusker Psychology Ltd | Health & social care | 2024 |
| Love Syndrome Productions Limited | Information & communication | 2023 |
| LR Mediclinic Ltd | Other services | 2026 |
| Luxus Milano UK Ltd | Professional & scientific | 2019 |
| Lyme Bay Arts C.I.C. | Wholesale & retail | 2018 |
| Lyme Bay Auctions Ltd | Wholesale & retail | 2013 |
| Lyme Bay EAR Clinic Ltd | Health & social care | 2020 |
| Lyme Bay Field Kitchen Ltd | Hospitality | 2014 |
| Lyme Bay Legal Limited | Professional & scientific | 2013 |
| Lyme Bay Storage Ltd | Other services | 2014 |
| Lyme Regis Marine Aquarium Limited | Arts & recreation | 2013 |
| Lyme's Fish Bar Ltd | Hospitality | 2010 |
| M C Welding and Pipe (SW) Ltd | Manufacturing | 2022 |
| M M Forward Ltd | Real estate | 2012 |
| MAE Coastal Properties Ltd | Real estate | 2025 |
| MAG Square Ltd | Wholesale & retail | 2025 |
| Magdalen Properties Limited | Households | 1995 |
| Major Terrace Management Ltd | Households | 2014 |
| Mamma MIA Portuguese Flavour Ltd | Wholesale & retail | 2023 |
| Management and Marketing Services UK Ltd | Professional & scientific | 2014 |
| Manor Farm Caravan & Camping Site Limited | Hospitality | 2013 |
| Manor Park (Seaton) Management Company Limited | Households | 2002 |
| Mariners Bar Management Limited | Health & social care | 1994 |
| Mashiter Ltd. | Information & communication | 2003 |
| Mashiter Properties Limited | Real estate | 2015 |
| Matt Austin Images Limited | Professional & scientific | 2013 |
| Matt Daines Building & Property Maintenance Ltd | Construction | 2013 |
| Matthews Brothers Properties Ltd | Real estate | 2021 |
| Mberd Aviation Limited | Transport & logistics | 2016 |
| Mcewan Estates Ltd | Real estate | 2024 |
| Mchemx Limited | Manufacturing | 2023 |
| Medicfi Ltd | Information & communication | 2022 |
| Meliora Psychology Ltd | Health & social care | 2022 |
| Metrix Productions Ltd | Information & communication | 2021 |
| MEW Developments Ltd | Construction | 2006 |
| Mightynorth Limited | Real estate | 1985 |
| Mike Cullum Electrical Ltd | Construction | 2025 |
| Millman Electrical Ltd | Construction | 2015 |
| Milton Keynes Riding Club Ltd | Arts & recreation | 2025 |
| Mind Matters Psychological Services Ltd | Health & social care | 2022 |
| Mindful Business Management Ltd | Professional & scientific | 2025 |
| Mindrhythm | Education | 2023 |
| Mocha Restaurant Limited | Hospitality | 2001 |
| Model Marine Limited | Extraterritorial | 1974 |
| Molly Baird Photography Ltd | Professional & scientific | 2023 |
| Moorebridge Limited | Administrative & support | 2026 |
| Morden Lacey Limited | Professional & scientific | 2011 |
| Morgan Heating Maintenance Limited | Construction | 1996 |
| Morgan Utilities (South West) Ltd | Construction | 2024 |
| Mountfield Road Management Limited | Households | 2012 |
| MQD Film Limited | Information & communication | 2019 |
| MR Locum Services Ltd | Professional & scientific | 2025 |
| MRK Equipment Limited | Administrative & support | 2026 |
| MRK Plant and Groundworks Ltd | Construction | 2025 |
| Mubu Developments Limited | Construction | 2018 |
| Multiblast Ltd | Construction | 2013 |
| MW Retail Ltd | Wholesale & retail | 2022 |
| My Accounts Department Limited | Extraterritorial | 2007 |
| My Inner Space Psychology Ltd | Health & social care | 2023 |
| Mynext Limited | Information & communication | 2009 |
| N M H Limited | Real estate | 2007 |
| Natural Worx CIC | Wholesale & retail | 2020 |
| Nccs (Global) Ltd | Professional & scientific | 2025 |
| NDT (Seaton) Ltd | Hospitality | 2022 |
| Neuropsychology Dorset Ltd | Health & social care | 2023 |
| Nevada Court (Seaton) Residents Association Limited | Households | 1980 |
| New Rooms Limited | Construction | 2002 |
| Next Motors (Surrey) Ltd. | Wholesale & retail | 2021 |
| NFW MEN in the Sun Ltd | Information & communication | 2022 |