| 21CST Partnership Limited | Real estate | 2020 |
| A & H Murray and Partners | | 2001 |
| A Carmichael & Partner | | 1996 |
| A E & R Macintyre (Dunallan) | | 2001 |
| A.H. Dickson & Partners | | 1998 |
| Access Systems Network Limited | Construction | 2024 |
| Alscaff Limited | Construction | 2022 |
| Ambrisbeg Limited | Mining & quarrying | 1992 |
| Ambrismore Farmers | | 1999 |
| Apple Tree Nursery Limited | Education | 2009 |
| Ardmaleish Boatbuilding Company Limited (the) | Manufacturing | 1975 |
| Ardmaleish Holdings Limited | Manufacturing | 2013 |
| Ascog Limited | Professional & scientific | 2003 |
| Baldy Installations Ltd | Construction | 2019 |
| Ballochgoy Ltd | Hospitality | 2025 |
| Balnancy L a Limited | Wholesale & retail | 2013 |
| BEL - AM Holdings Limited | Professional & scientific | 2017 |
| Blosshome Limited | Real estate | 2019 |
| Bonnie Bling Ltd | Manufacturing | 2022 |
| Boxnexus Ltd | Information & communication | 2026 |
| Bute Berthing Co Limited | Transport & logistics | 1993 |
| Bute Blacksmiths Limited | Manufacturing | 2005 |
| Bute Boat Tours Ltd | Transport & logistics | 2019 |
| Bute Community Media Limited | Information & communication | 2002 |
| Bute Dental Care Limited | Health & social care | 2024 |
| Bute Developments Limited | Real estate | 2025 |
| Bute Fabrics Limited | Manufacturing | 1977 |
| Bute Factors Ltd | Administrative & support | 2018 |
| Bute Homes Limited | Administrative & support | 2010 |
| Bute Island Developments Ltd | Real estate | 2021 |
| Bute Island Foods Ltd. | Manufacturing | 2002 |
| Bute Jazz Concerts Ltd | Arts & recreation | 2008 |
| Bute Management Services Ltd | Construction | 2023 |
| Bute Noir Community Interest Company | Arts & recreation | 2026 |
| Bute Plumbing Services Limited | Construction | 2025 |
| Bute Property Limited | Real estate | 2006 |
| Bute Retreats Ltd | Hospitality | 2025 |
| Bute Venison Ltd | Manufacturing | 2022 |
| Bute's Bounty Ltd. | Manufacturing | 2023 |
| Colmac Milk Limited | Agriculture & fishing | 2023 |
| Craigberoch Business Decelerator Limited | Professional & scientific | 2019 |
| Craigberoch Trust Limited | Other services | 2020 |
| Critical Resources (International) Limited | Professional & scientific | 2015 |
| Crystal Electrical Services Ltd | Construction | 2020 |
| D.M. & J.L. Mcalister Nether Ardroscadale Farm | | 1998 |
| DI Diving Limited | Agriculture & fishing | 2026 |
| Dirt Road Ltd | Information & communication | 2015 |
| DMC Vehicle Solutions Ltd | Wholesale & retail | 2024 |
| Donald Mcalister Joiner Limited | Construction | 2017 |
| DYN Electrical Services Ltd | Professional & scientific | 2022 |
| Edgar BSL Ltd | Professional & scientific | 2014 |
| Eider Bakery Ltd | Hospitality | 2023 |
| Elenkus Ltd | Information & communication | 2008 |
| Emily Lamb Art Ltd | Arts & recreation | 2020 |
| Emreyn Engineering Limited | Manufacturing | 2008 |
| Ettrick Bay Cafe Ltd | Hospitality | 2025 |
| Farmrecord Ltd | Information & communication | 2026 |
| FUN GUY Mushrooms Ltd | Agriculture & fishing | 2025 |
| Fyne Energy Limited | Energy | 2016 |
| Fyne Futures | Agriculture & fishing | 2005 |
| Fyne Initiatives Limited | Construction | 2005 |
| G12IT Ltd | Information & communication | 2021 |
| Gather Deli Ltd | Manufacturing | 2021 |
| Gbyte Consulting Ltd | Information & communication | 2024 |
| George Hanson (Building Contractors) Limited | Construction | 1990 |
| Glamping by the Bay Limited | Hospitality | 2017 |
| GSM Shopfitting Ltd | Construction | 2011 |
| GT88 Rentals Ltd | Administrative & support | 2025 |
| Hunter Builders Bute Limited | Construction | 2019 |
| Iain F. Crawford Farmers | | 1996 |
| Imoc Limited | Real estate | 2021 |
| Industrial Heritage Consulting Ltd. | Professional & scientific | 2006 |
| Isle of Bute Coffee Ltd | Manufacturing | 2023 |
| J & J Zan-Kreyser Taxis Ltd | Transport & logistics | 2023 |
| Jane Hare Limited | Construction | 2018 |
| JAS Marine Ltd | Extraterritorial | 2020 |
| JOE Macadam Ltd | Construction | 2023 |
| Jones House Ltd | Real estate | 2025 |
| K.M.M. Limited | Administrative & support | 1998 |
| Katlam Limited | Hospitality | 2022 |
| Kdrum Limited | Administrative & support | 2023 |
| Kingarth Farm Limited | Wholesale & retail | 2014 |
| Lambertini Lettings Ltd | Real estate | 2025 |
| Lang Property Management Limited | Real estate | 2022 |
| Leviathan Property Ltd | Real estate | 2026 |
| Loch FAD Fisheries Limited | Agriculture & fishing | 1998 |
| Mackallan Limited | Real estate | 2022 |
| Marcall Catering Ltd | Hospitality | 2023 |
| MDS GAS Services Ltd | Construction | 2026 |
| Messrs. Kerrycroy Farmers | | 1997 |
| MID Ascog Limited | Agriculture & fishing | 2022 |
| Montague and Delucter Ltd | Real estate | 2020 |
| Moonshine and Madness Ltd. | Arts & recreation | 2017 |
| Myheep Ltd | Other services | 2025 |
| Nether Strauannan Farm | | 1989 |
| Nicholson Mccallum Ltd | Financial services | 2021 |
| NÜ Smile Ltd | Health & social care | 2024 |
| ON Tranquil Shores Ltd | Real estate | 2021 |
| One 2 One Accountancy Services Ltd | Professional & scientific | 2024 |
| Orient Salon Limited | Other services | 2020 |