| Redwood Research Ltd | Professional & scientific | 2024 |
| Reid's Renovations Ltd | Construction | 2026 |
| Repfros Ltd | Information & communication | 2019 |
| Revolutionary Spirit Films Ltd | Information & communication | 2024 |
| Richard Edward and Company (Scotland) Limited | Agriculture & fishing | 2012 |
| Richard Hirst Limited | Construction | 2020 |
| Richard Townsley Limited | Health & social care | 2022 |
| Riga Convience Store Ltd | Wholesale & retail | 2025 |
| Robert C Brady Limited | Administrative & support | 2017 |
| Robin Hamilton Autos Limited | Wholesale & retail | 2009 |
| Rockrose Equestrian Limited | Arts & recreation | 2014 |
| Rona Duncan Ceremonies Ltd | Other services | 2021 |
| Roots & Shoots Landscaping Ltd | Administrative & support | 2022 |
| Rope Base Rigging & Rescue Ltd | Arts & recreation | 2019 |
| Roserocco Ltd | Professional & scientific | 2023 |
| Ross and Outchester Farms Limited | Hospitality | 1960 |
| Rutherford Archway Homes Ltd | Real estate | 2021 |
| S1 Dental Limited | Financial services | 2025 |
| Saltire Executive Golf Limited | Other services | 2013 |
| Samuelston Renewables Ltd | Energy | 2014 |
| Sandy Soles Ltd | Wholesale & retail | 2017 |
| Scotland's Golf Coast Limited | Other services | 2013 |
| Scott Clark Photography Ltd | Professional & scientific | 2025 |
| Scott's Relocation Limited | Real estate | 2024 |
| Seol Trust | Health & social care | 2019 |
| SKG Digital Holdings Ltd | Construction | 2026 |
| SKG Security Limited | Administrative & support | 1998 |
| Skills to Action Ltd | Education | 2025 |
| Skunabay Ltd | Administrative & support | 2017 |
| Sky Rocket Wellness Ltd | Health & social care | 2012 |
| Smith Brands Limited | Information & communication | 2005 |
| SMJ Consulting Services Ltd | Administrative & support | 2016 |
| SN Cleaning Services Ltd | Administrative & support | 2026 |
| Social Sparkle Ltd | Administrative & support | 2026 |
| Sol.Haddington Ltd | Other services | 2025 |
| Somnerfield Feuars (Number 2) Limited | Households | 1974 |
| Somnerfield Feuars Limited | Households | 1973 |
| Sophia Grace Couture Ltd | Wholesale & retail | 2015 |
| Speedyfeet Couriers Ltd | Transport & logistics | 2026 |
| Spellcaster UK Ltd | Information & communication | 2020 |
| Spencer Dixon Limited | Transport & logistics | 2010 |
| Sportsworld (North East) Limited | Wholesale & retail | 1990 |
| Spyder Rope Access and Rigging Ltd | Construction | 2025 |
| Squeaky Clean (Scotland) Limited | Administrative & support | 2024 |
| ST Golf Limited | Wholesale & retail | 2021 |
| Stanhope Nine LLP | | 2009 |
| Stenhouse Transport Limited | Wholesale & retail | 2017 |
| Stirton Consulting Ltd | Professional & scientific | 2014 |
| Strathern Limited | Professional & scientific | 1988 |
| Strike Lightning Protection Services Limited | Construction | 2008 |
| Strike Rate Cricket Ltd | Arts & recreation | 2026 |
| Strome Project Consulting Limited | Professional & scientific | 2018 |
| Student Accommodation Finder Service Ltd | Administrative & support | 2024 |
| Sustainable Technology Information and Research Ltd | Professional & scientific | 2026 |
| Swift Service PVT Ltd | Transport & logistics | 2022 |
| Swiftnut Limited | Manufacturing | 2012 |
| Synvoice AI Ltd | Information & communication | 2025 |
| T Sethi Consulting Limited | Professional & scientific | 2025 |
| Tarragon Limited | Hospitality | 2018 |
| Tavaci Limited | Hospitality | 2023 |
| Telford Retail Ltd | Wholesale & retail | 2025 |
| Tengu Security Ltd | Information & communication | 2017 |
| THE Business Base Haddington Limited | Professional & scientific | 2007 |
| THE Car and Van Rental Co. Ltd. | Wholesale & retail | 1993 |
| THE Cauldshiel Cattle Company Ltd | Agriculture & fishing | 2012 |
| THE Changing Room Barbershop Ltd | Other services | 2024 |
| THE Cheese Lady Limited | Wholesale & retail | 2021 |
| THE Chocolate Tree Limited | Manufacturing | 2006 |
| THE Golf Tavern Limited | Hospitality | 2008 |
| THE Haddington Bridge Centre | Education | 2007 |
| THE Haddington Community Interest Company | Arts & recreation | 2025 |
| THE Lamp of Lothian Trust | Arts & recreation | 2010 |
| THE Life Science Trust | Professional & scientific | 1992 |
| THE Loft Cafe and Bakery Limited | Hospitality | 2015 |
| THE Multi Fuel Stove Company Limited | Wholesale & retail | 2013 |
| THE Nest Play Cafe Ltd | Hospitality | 2024 |
| THE Original Doggie Daycare Company Ltd | Other services | 2016 |
| THE Rehab Dietitian Limited | Health & social care | 2021 |
| THE Scottish Halibut Company Ltd | Agriculture & fishing | 2024 |
| THE Sound of Young Scotland Ltd. | Information & communication | 2015 |
| THE Stewart Partnership | | 1997 |
| THE Systems Solutions Consultancy Limited | Information & communication | 1995 |
| THE Traprain Club Ltd | Arts & recreation | 2026 |
| THE Virtual Hamilton Palace Trust | Arts & recreation | 2003 |
| THE Wellness Lounge Cockenzie Limited | Other services | 2023 |
| Thomas G Ltd | Professional & scientific | 2018 |
| Thomson and White Painters and Decorators Ltd | Construction | 2024 |
| Ticketed.App Ltd | Information & communication | 2019 |
| Tiwona Limited | Health & social care | 2025 |
| Touch of Glass Ltd | Administrative & support | 2026 |
| Transport Times Events Limited | Administrative & support | 2021 |
| Tremmel Guard Limited | Manufacturing | 2024 |
| Tremmel Properties Ltd. | Construction | 1996 |
| Triggerfish Entertainment UK Ltd | Information & communication | 2022 |
| Turas Dana Limited | Wholesale & retail | 2023 |
| TUX Games Ltd | Information & communication | 2024 |
| Tweedside Bathrooms Limited | Construction | 2025 |
| Two (Pbsa) Holding LLP | | 2023 |
| Tyne Holdings (Scotland) Ltd | Real estate | 2025 |
| Tyne Property Developments Ltd | Construction | 2015 |