| Leamar Homes Limited | Construction | 2003 |
| LEE Mackay Joiner Contractor Ltd | Construction | 2015 |
| LGR Joinery Ltd | Construction | 2021 |
| Lochshell Holdings Limited | Administrative & support | 2021 |
| LSW Services Ltd | Mining & quarrying | 2021 |
| Lyth Arts Centre Ltd | Arts & recreation | 2017 |
| M & G Solutions Ltd | Construction | 2013 |
| M & R Campbell Joinery Ltd | Construction | 2022 |
| M D Joinery (Wick) Limited | Construction | 2017 |
| M Gunn Technical Services Ltd | Professional & scientific | 2021 |
| M.B.M. Farms Ltd. | Agriculture & fishing | 1997 |
| MAC Engineering(Caithness) Ltd | Wholesale & retail | 2014 |
| Mackay Holiday Lets Limited | Hospitality | 2025 |
| Mackay Hotel Company Ltd | Hospitality | 2006 |
| Mackay Joinery Ltd | Construction | 2025 |
| Mackinnonpotterys Ltd | Manufacturing | 2022 |
| Macnab CPM Ltd | Real estate | 2020 |
| Macnab Property Investment Ltd | Hospitality | 2023 |
| Maid in Caithness Ltd | Administrative & support | 2025 |
| Mainline Links Ltd | Wholesale & retail | 2010 |
| Malcolms Shop Ltd | Wholesale & retail | 2013 |
| Marine Diving Solutions Ltd | Construction | 2021 |
| Matmac Joinery Ltd | Construction | 2016 |
| Matthew Tucker Ltd | Agriculture & fishing | 2025 |
| MBT Engineering and Fabrication Ltd | Agriculture & fishing | 2012 |
| Mcallan & Company (Painters) Limited | Construction | 1975 |
| Mcewan Legal Auditors Limited | Professional & scientific | 2021 |
| Mckay Auto Centre Ltd | Wholesale & retail | 2025 |
| ME Engineering Group Limited | Professional & scientific | 2018 |
| MH Spice Ltd | Hospitality | 2026 |
| Miller Engineering Design Ltd | Construction | 2015 |
| Miller Engineering Services Ltd | Professional & scientific | 2003 |
| Miller Fishing Co Ltd | Agriculture & fishing | 2025 |
| Miller Luxury Retreats Ltd | Hospitality | 2023 |
| Miltec Agricultural Limited | Manufacturing | 1983 |
| MJD Electrical Solutions Ltd | Construction | 2024 |
| Mkith Rentals Ltd | Real estate | 2018 |
| MM A&A Ltd | Professional & scientific | 2022 |
| Montylu Limited | Wholesale & retail | 2014 |
| Moose Hoose Holidays Ltd | Real estate | 2021 |
| More Than Motivation Ltd | Professional & scientific | 2019 |
| Morvenops Limited | Professional & scientific | 2025 |
| Mountain DEW Bar Ltd | Hospitality | 2024 |
| MTG Properties Limited | Real estate | 2025 |
| Muddy Dog Limited | Professional & scientific | 2010 |
| Murray Anderson(Floor Coverings) Ltd. | Wholesale & retail | 2004 |
| NCD 1 Limited | Manufacturing | 2019 |
| Nethercliffe Hotel Ltd | Hospitality | 2005 |
| New Vision Caithness Ltd | Real estate | 2025 |
| Nicola More Creative Ltd | Professional & scientific | 2024 |
| NMG Contracts Limited | Construction | 2016 |
| NO Limits Caithness | Health & social care | 2012 |
| Norblast Ltd | Administrative & support | 2020 |
| Norcad Engineering Ltd | Professional & scientific | 2013 |
| Norscot Joinery (Holdings) Limited | Financial services | 2014 |
| Norscot Joinery Limited | Construction | 1984 |
| Norse V3 Ltd | Professional & scientific | 2022 |
| North Coast Competitions Ltd | Other services | 2021 |
| North Coast Fishing Co Ltd | Agriculture & fishing | 2016 |
| North Coast Painting and Decorating Ltd | Construction | 2016 |
| North Highland Autos Ltd | Wholesale & retail | 2026 |
| North Highland Initiative | Administrative & support | 2008 |
| North Highland Products Limited | Wholesale & retail | 2012 |
| North Wick Restaurant Limited | Hospitality | 2019 |
| Noss Farm Ltd | Agriculture & fishing | 2003 |
| Nosspitality Limited | Hospitality | 2024 |
| NPS North Ltd | Professional & scientific | 2024 |
| Ntrust Support Services Limited | Health & social care | 2018 |
| Octumus Limited | Wholesale & retail | 2026 |
| OIL and Storage Services Limited | Administrative & support | 2004 |
| Omni Global Partners LLP | | 2015 |
| Organic Works Ltd | Wholesale & retail | 2019 |
| P and O Group Ltd | Financial services | 2022 |
| P and O Scaffolding Services Ltd | Construction | 2018 |
| P Geddes Electrical Limited | Construction | 2024 |
| Parkhead Fishing Co Ltd | Agriculture & fishing | 2017 |
| Pentland Offshore Services Limited | Professional & scientific | 2017 |
| Pentland Properties (Scotland) Ltd | Real estate | 2011 |
| Pizza Bank Limited | Hospitality | 2025 |
| POS Scaffolding Services Ltd | Construction | 2023 |
| Premier Highland Rentals Ltd | Real estate | 2026 |
| Production Process Support Services Ltd | Mining & quarrying | 2022 |
| Puldagon Farm Shop & Restaurant Ltd | Hospitality | 2019 |
| Pulteney Properties Limited | Extraterritorial | 2004 |
| Pulteneytown People's Project | Administrative & support | 2004 |
| R Amin Property Development Ltd | Real estate | 2022 |
| R Begg Electrical Services Limited | Energy | 2008 |
| R G Macdonald Limited | Manufacturing | 2011 |
| R Sutherland Electrical Ltd | Construction | 2022 |
| RAE Electrical Ltd | Manufacturing | 2016 |
| Raquex Ltd | Manufacturing | 2019 |
| Rasstech Limited | Professional & scientific | 2016 |
| Raven Farm Properties Ltd | Construction | 2025 |
| RBC Access Ltd | Professional & scientific | 2018 |
| Reaper White Fish Company Limited | Agriculture & fishing | 2018 |
| Resurgem Engineering Co. Limited | Manufacturing | 1973 |
| Richard Bain Ltd | Financial services | 2013 |
| Richard's Garage Limited | Wholesale & retail | 1981 |
| Riverside Apartments.Scot Ltd | Hospitality | 2017 |
| RM Rentals Wick Ltd | Real estate | 2025 |