| Ingram Motoring Group Limited | Wholesale & retail | 1974 |
| Integrated Ceilings & Partitions Limited | Construction | 1993 |
| Inverglen Scotch Whisky Co. Limited | Wholesale & retail | 1970 |
| Island Craft Clothing Company | | 1994 |
| Isle View Spa Thai Massage & Wellness Ltd | Other services | 2026 |
| J & D Pierce (Contracts) Ltd. | Manufacturing | 1997 |
| J.C. Peacock & Co., Limited | Manufacturing | 1947 |
| James Forrest Agricultural Contractors Limited | Agriculture & fishing | 2005 |
| James G Young (Investments) Limited | Professional & scientific | 2001 |
| James G. Brodlie Limited | Health & social care | 1982 |
| James Gibb (Animal Feeds) Limited | Wholesale & retail | 1988 |
| James Wilson & SON (Auchmillan) Limited | Construction | 1957 |
| Jenicam Construction Limited | Construction | 2006 |
| Jetstream Aircraft Limited | Extraterritorial | 1992 |
| JIM Wylie Mortgage & Financial Services Limited | Financial services | 2003 |
| John B. Scott Limited | Agriculture & fishing | 1975 |
| John Craig & Sons(Contractors)Limited | Construction | 1976 |
| John H Mcnae Ltd. | Wholesale & retail | 2005 |
| John Kirkland Glenside | | 1987 |
| John Mcaulay (Fairlie) Limited | Construction | 1975 |
| John Whiteford Garages Limited | Construction | 2002 |
| Joseph Waldron Ltd | Transport & logistics | 2025 |
| JST (Port Services) Ltd. | Transport & logistics | 2001 |
| K K Draught Drinks Limited | Manufacturing | 2006 |
| Kerr Baillie Limited | Wholesale & retail | 1966 |
| Kilmarnock Land Co. Ltd. | Real estate | 2007 |
| Kilpatrick & Walker Nominees Limited | Professional & scientific | 1996 |
| Kilpatrick & Walker Trustees Limited | Professional & scientific | 1996 |
| L & M Therapeutic Services CIC | Health & social care | 2019 |
| Ladybank Farm | | 1985 |
| Ladybank Farming Company | | 1988 |
| Lanfine Holdings Limited | Manufacturing | 1973 |
| Lawrie Brothers (Sandyford) | | 2002 |
| Lazy Mist Records Limited | Arts & recreation | 2000 |
| Lemon Tree T/A Shafs Chippy Ltd | Hospitality | 2025 |
| Let's Escape Motorhomes Ltd | Administrative & support | 2020 |
| Lime Tree Larder Limited | Professional & scientific | 2003 |
| LM Edge Logistics Ltd | Transport & logistics | 2025 |
| Lochridge Hills Farms Ltd | Agriculture & fishing | 2023 |
| Lokring Europe Limited | Wholesale & retail | 2005 |
| Loudoun Mains Luxury Lodges Ltd | Hospitality | 2024 |
| Loudoun Valley Trust | Health & social care | 1993 |
| Loudounhill Contracts Limited | Mining & quarrying | 1986 |
| LOW Greenbank Railway Bridge Company Limited | Real estate | 1992 |
| Lumax Homes Limited | Construction | 2002 |
| Lyndsay Mccurry Ltd | Transport & logistics | 2025 |
| M Ross Taylor & Partners | | 1980 |
| Macfarlane Labels Limited | Manufacturing | 1949 |
| Machined Components Limited | Manufacturing | 1928 |
| Mair Matheson Limited | Real estate | 2001 |
| Manor Park Financial Services Limited | Financial services | 1991 |
| Manor Park Pensions and Investments Limited | Professional & scientific | 1990 |
| Marry Harry Limited | Hospitality | 2003 |
| Mason Omoa Limited | Agriculture & fishing | 1970 |
| Mauchline Bing Limited | Extraterritorial | 2018 |
| MAX Promotions Limited | Administrative & support | 1999 |
| Maybank Motors Limited | Wholesale & retail | 1996 |
| Mcfadzean Motor Engineering Limited | Wholesale & retail | 2005 |
| Mckinlay Properties (Troon) Limited | Real estate | 2003 |
| Mcnab Improvements Ltd | Construction | 2003 |
| Mickle Enterprises Limited | Wholesale & retail | 2003 |
| MID Carrick Properties Ltd. | Real estate | 2002 |
| Middlepart Limited | Agriculture & fishing | 2004 |
| Milligans Coach Travel Limited | Transport & logistics | 2003 |
| Millside Properties Limited | Real estate | 1964 |
| Mindstore International Limited | Education | 2004 |
| Minuntion Sporting Company Limited | Arts & recreation | 2006 |
| Mitchell's Stores Limited | Wholesale & retail | 2003 |
| Morayside Limited | Energy | 2023 |
| Mortgage Master (Glasgow) Ltd. | Financial services | 1998 |
| MRC Fitness & Leisure Limited | Arts & recreation | 1984 |
| Murphy Builders Limited | Construction | 1994 |
| NB Design Engineering Limited | Professional & scientific | 2007 |
| Nether Landscapes Limited | Administrative & support | 2016 |
| Netherside Limited | Energy | 2023 |
| New Futures (Scotland) Limited | Health & social care | 2022 |
| North Shaw Farming Company | | 1990 |
| Nova Cement Scotland Limited | Wholesale & retail | 2023 |
| NS Indian Cuisine Ltd | | 2011 |
| Odds on Book-Makers | | 2001 |
| P.P.I.G. Limited | Manufacturing | 2002 |
| Pacific Shelf 1065 Limited | Professional & scientific | 2001 |
| Pacific Shelf 1281 Limited | Real estate | 2004 |
| Pacific Shelf 1282 Limited | Real estate | 2004 |
| Paladin Financial Services Limited | Financial services | 1998 |
| Pantrak Transportation Limited | Professional & scientific | 2001 |
| Paul Stevenson Funeral Directors Ltd. | Other services | 1994 |
| Peacock Salt Limited | Wholesale & retail | 1955 |
| Peter Drummond, Architect Ltd | Professional & scientific | 2007 |
| Phoenix Plumbers Limited | Construction | 2003 |
| Pierside Limited | Energy | 2021 |
| Pisgah Farm | | 1991 |
| Plan (Borders) Limited | Real estate | 2006 |
| Plastic Rotational Mouldings Ltd. | Extraterritorial | 2004 |
| Portland Laboratory Services Limited | Health & social care | 1987 |
| Positively Legal Limited | Professional & scientific | 2001 |
| Pro-Fitt Flooring Limited | Professional & scientific | 2004 |
| Protec Training & Consultancy Ltd. | Professional & scientific | 2002 |
| PWR Bioheat Limited | Construction | 2013 |
| R & L Miller Limited | Wholesale & retail | 2004 |