| Morley’S Haulage Ltd | Transport & logistics | 2024 |
| Morton Toop Accounts Limited | Professional & scientific | 2014 |
| MOT Stop Limited | Wholesale & retail | 2000 |
| Motoshed UK Limited | Wholesale & retail | 2020 |
| Mountain Beauty (SP) Ltd | Other services | 2022 |
| Move on Homes Limited | Real estate | 2018 |
| Move-It Finance | | 2004 |
| Movil Zone Ltd | Wholesale & retail | 2019 |
| Mowlam Metalcraft Ltd | Manufacturing | 2000 |
| Mowlam Transport Ltd | Transport & logistics | 2021 |
| Moxom Joinery Limited | Manufacturing | 2008 |
| Moxoms (Dorset) Limited | Administrative & support | 2012 |
| MP Homes and Management Ltd | Real estate | 2023 |
| Mpks Solutions Limited | Professional & scientific | 2017 |
| MPS (SW) Limited | Other services | 2018 |
| MRL 3 Ltd | Wholesale & retail | 2014 |
| MRS B'S Bakes Ltd | Wholesale & retail | 2008 |
| MSW Build Limited | Construction | 2014 |
| Mucha Foundation Services Ltd | Professional & scientific | 2017 |
| Muir and Associates Ltd | Health & social care | 2022 |
| Mullan Civils Limited | Construction | 2021 |
| Mumma Bee’S Cafe Ltd | Hospitality | 2024 |
| Muntsy's Community Care Activities Ltd | Health & social care | 2010 |
| MW 86 Limited | Hospitality | 2016 |
| MW Legal Services Ltd | Professional & scientific | 2022 |
| MW Lettings Ltd | Real estate | 2021 |
| MW WEY Limited | Hospitality | 2016 |
| MWT Safety Engineering Limited | Professional & scientific | 2014 |
| My Care My Choice Ltd | Health & social care | 2024 |
| My Static Caravan Ltd | Wholesale & retail | 2022 |
| Myriad Project Management & Design Limited | Professional & scientific | 2013 |
| N & R Roberts Holdings Limited | Financial services | 2025 |
| N a Caswell Housing Limited | Real estate | 2006 |
| N and I Finney Transport Ltd | Transport & logistics | 2019 |
| N and P Plumbing and Heating Limited | Construction | 2001 |
| N Bascombe Motor Services Limited | Wholesale & retail | 2019 |
| N C Groundworks and Drainage Solutions Ltd | Construction | 2021 |
| N Read Limited | Construction | 2008 |
| N.A. Caswell Building Limited | Construction | 2001 |
| Nagel Services Kent Limited | Construction | 2020 |
| Nagel Services S E Limited | Construction | 2014 |
| Naked Telecom Limited | Information & communication | 2013 |
| NAM Poole Limited | Hospitality | 2024 |
| Nanayakara Ltd | Wholesale & retail | 2021 |
| Natalie Worth Studio Limited | Other services | 2026 |
| Natural Balance Dog Training Ltd | Agriculture & fishing | 2011 |
| Natural Productions (SW) Limited | Professional & scientific | 2011 |
| Nature's Nook Forest School Limited | Education | 2025 |
| Naughty Forks Desserts Ltd | Hospitality | 2020 |
| Nautica South Ltd | Hospitality | 2015 |
| Nautilus Attraction Developments Limited | Arts & recreation | 2014 |
| Naxavend Ltd | Wholesale & retail | 2026 |
| NB Services (South) Ltd | Administrative & support | 2018 |
| NBC Logistic Ltd | Transport & logistics | 2026 |
| NCA Coaching Limited | Other services | 2018 |
| NCA CRM Limited | Other services | 2025 |
| NCA Softwares LLP | | 2026 |
| NDP Property Southampton Ltd | Real estate | 2024 |
| Neals Flats RTM Company Limited | Households | 2025 |
| Neil Rogers M&E Project Management Ltd | Administrative & support | 2017 |
| Nelson Wharf Limited | Transport & logistics | 1998 |
| Neptune Automotive Limited | Wholesale & retail | 2023 |
| Neptune Technology Ltd | Information & communication | 2023 |
| Netriver Systems Limited | Information & communication | 2014 |
| Netronics Limited | Manufacturing | 1999 |
| New Abbey Developments LLP | Construction | 2013 |
| New Body (Bridport) Limited | Arts & recreation | 2016 |
| New Body (Dorset) Limited | Wholesale & retail | 2017 |
| New Body (Weymouth) Limited | Arts & recreation | 2013 |
| New Body Group Ltd | Arts & recreation | 2025 |
| New Horizon Survey Ltd | Wholesale & retail | 2012 |
| New Image Tile Studio Limited | Manufacturing | 2003 |
| New Joy WOK Limited | Hospitality | 2022 |
| New Look Limited | Professional & scientific | 1986 |
| New Look Retailers Limited | Wholesale & retail | 1982 |
| Newland FIC Limited | Professional & scientific | 2026 |
| Newstead Cottage Ltd | Real estate | 2024 |
| NGS Staff Solutions Ltd | Information & communication | 2020 |
| Niall Laming (Builders) Limited | Real estate | 2012 |
| Nice N Spicey Weymouth Limited | Hospitality | 2023 |
| Nice to Meet YOU Limited | Hospitality | 2025 |
| Nicetta Limited | Hospitality | 2017 |
| Nicholas Carroll & Financial Associates Limited | Administrative & support | 2023 |
| Nick C Green Ltd | Hospitality | 2023 |
| Nightingale Mortgages Limited | Financial services | 2006 |
| Nightworks Ltd | Real estate | 2019 |
| NIK Retail Limited | Professional & scientific | 2024 |
| NJB Marine Ltd | Manufacturing | 2023 |
| Njdmarine Ltd | Other services | 2017 |
| NL Property Holdings Limited | Real estate | 2024 |
| NO Brolly Ltd | Wholesale & retail | 2025 |
| NO Judgement Car Sales Ltd | Wholesale & retail | 2020 |
| NO. 35 Boutique Accommodation Limited | Hospitality | 2013 |
| Noble Manhattan Coaching UK AG Ltd | Other services | 2021 |
| Noble Truth Limited | Information & communication | 2020 |
| Noddy's Cider Ltd | Manufacturing | 2018 |
| Nomadic Spirit Drinks Limited | Manufacturing | 2024 |
| None of Your Business Weymouth Limited | Real estate | 2024 |
| Nordale Pet and Farm Supplies Limited | Agriculture & fishing | 2017 |
| North Mead Farm Limited | Construction | 2014 |