| Siteman Services (Scotland) Ltd. | Professional & scientific | 2011 |
| Sizzlick Ltd | Hospitality | 2023 |
| SJR Beauty Therapies Ltd | Other services | 2019 |
| Sky Smoking Store Ltd | Wholesale & retail | 2025 |
| Skyline Scaffolding Ayrshire Ltd | Construction | 2025 |
| SL & EL Limited | Wholesale & retail | 2013 |
| SL Medics Ltd | Wholesale & retail | 2015 |
| SM Plastering Glasgow Limited | Construction | 2025 |
| Small Talk (Ayrshire) Ltd | Hospitality | 2019 |
| Smalltown Audio Ltd | Administrative & support | 2012 |
| Smart FX Alloy Wheel and Bumper Repairs Limited | Wholesale & retail | 2014 |
| Smarter Accounting and Tax Solutions Ltd | Professional & scientific | 2022 |
| Smoke Cloud Ltd | Other services | 2017 |
| Sole Works Ltd | Health & social care | 2025 |
| Sophies Choice Catering Ltd | Hospitality | 2015 |
| Soul Sisters Limited | Hospitality | 2017 |
| SPARES4REPAIRS Ltd | Wholesale & retail | 2024 |
| Spearhead Management Services Limited | Professional & scientific | 2006 |
| SS Pizza AYR Ltd | Manufacturing | 2025 |
| Ssge Scaffolding Ltd | Construction | 2025 |
| ST Andrews Accommodation Limited | Hospitality | 2021 |
| Stan Wardrop Limited | Transport & logistics | 2023 |
| Steakd Ltd | Information & communication | 2023 |
| Stevens Cunningham Limited | Professional & scientific | 2018 |
| Stevenston Enterprise Ltd | Wholesale & retail | 2023 |
| Storm Improve Ltd | Construction | 2009 |
| Stormfab Ltd | Manufacturing | 2022 |
| Streamline Energy Limited | Professional & scientific | 2024 |
| Structural Surveys & Design Scotland Ltd | Professional & scientific | 2020 |
| Style 4 ALL Ltd | Wholesale & retail | 2016 |
| Style Range Fashion Ltd | Wholesale & retail | 2025 |
| Summel Outside Catering & Events Ltd | Hospitality | 2024 |
| Summel Properties Ltd | Real estate | 2018 |
| Summer Holding Ltd | Manufacturing | 2019 |
| Superspout Limited | Manufacturing | 2008 |
| Surefix Roofing Solutions Ltd | Construction | 2024 |
| SW Aesthetics Irvine T/A SW Aesthetics Ltd | Health & social care | 2024 |
| SW Skin Ltd | Health & social care | 2023 |
| Swan Domestics Ltd | Real estate | 2022 |
| Swatt Electrical Solutions Ltd | Construction | 2022 |
| Swoon Property Ltd | Real estate | 2024 |
| Tanner Financial Advice Ltd | Financial services | 2013 |
| Tasty Bite Hub Ltd | Hospitality | 2025 |
| Taxi Call (Irvine) Ltd | Transport & logistics | 2022 |
| TAY Homes Limited | Construction | 2021 |
| TCT Industrial Roofing Ltd | Construction | 2014 |
| TCT Property & Accommodation Limited | Hospitality | 2026 |
| TDM Home Services Ltd | Manufacturing | 2026 |
| Technology Equipment Suppliers Ltd | Professional & scientific | 2015 |
| Tes-Amm (Europe) Ltd. | Water & waste | 2005 |
| THE Booth Welsh Trust Limited | Financial services | 2025 |
| THE Bothan Limited | Real estate | 2012 |
| THE Bothy (Dreghorn) Ltd | Hospitality | 2017 |
| THE Bowden Hair LLP | | 2017 |
| THE Cladding and Roofing Company Ltd | Construction | 2019 |
| THE Dessert Retail Co Ltd | Wholesale & retail | 2019 |
| THE Dressing Room (Ayrshire) Ltd | Wholesale & retail | 2018 |
| THE Gentleman's Mane Barbers LP | | 2019 |
| THE Key Centre Limited | Other services | 2004 |
| THE Melville Foundation | Other services | 2023 |
| THE Music Room (Ayrshire) Ltd | Education | 2024 |
| THE November Collective Ltd | Professional & scientific | 2025 |
| THE Picture Framer (Glasgow) Ltd | Professional & scientific | 2014 |
| THE Project Controls Pool Limited | Professional & scientific | 2023 |
| THE Scottish Maritime Trust | Arts & recreation | 2005 |
| THE Sgian Dubh Company Limited | Extraterritorial | 2000 |
| THE Social Garage Project C.I.C. | Wholesale & retail | 2026 |
| THE Three Sixty Ayrshire Ltd. | Health & social care | 1996 |
| THE Works Salon Ltd | Other services | 2023 |
| THEINN5 Ltd | Hospitality | 2025 |
| Thermal Fabrication Services Ltd | Construction | 2022 |
| This IS Project Ltd | Professional & scientific | 2023 |
| Thistle Commercial Consultancy Limited | Energy | 2017 |
| Thistle Help Limited | Wholesale & retail | 2007 |
| Thistle Housing Services Limited | Administrative & support | 1997 |
| Thornhouse Ltd | Extraterritorial | 2024 |
| Timberworx Manufactured Joinery Ltd | Construction | 2023 |
| Timmy's Tasty Limited | Hospitality | 2021 |
| TKS Plumbing Services Ltd | Professional & scientific | 2018 |
| Tomahawk Access Ltd | Construction | 2026 |
| Tonys Gyros Ltd | Hospitality | 2025 |
| Topchef 88 Limited | Hospitality | 2025 |
| Total Tickets Ltd | Information & communication | 2014 |
| Tower Properties (Ayrshire) Limited | Real estate | 2018 |
| Townfoot Holdings Ltd | Real estate | 2016 |
| Townhead Research Limited Partnership | | 2000 |
| Transform Property Group Ltd | Real estate | 2025 |
| Transform PT Ltd | Health & social care | 2021 |
| Trinity Park Plumbing & Heating Ltd | Construction | 2024 |
| Trusted Tech Team, Inc. | | 2022 |
| TSC Consulting Ltd | Professional & scientific | 2022 |
| Turkish Hair Place Limited | Other services | 2021 |
| TWB Consultancy Ltd | Professional & scientific | 2026 |
| Tygris US (Holdings) Limited | Financial services | 2023 |
| Tynole Ltd | Professional & scientific | 2017 |
| Tyrewise Irvine Ltd | Wholesale & retail | 2022 |
| UK Storage Solutions Ltd | Other services | 2018 |
| Ultimate Contact Manager Limited | Professional & scientific | 2013 |
| United Food LR Ltd | Hospitality | 2026 |
| Universal Estates & Developments Limited | Real estate | 1993 |