| MJB Geocon Limited | Professional & scientific | 2013 |
| Mumfords Southwold Limited | Wholesale & retail | 2019 |
| NA Hansell Lifestyle Cookery Limited | Education | 2011 |
| Neutral Express Service Limited | Transport & logistics | 2007 |
| Nicholson (Needham) Limited | Construction | 2017 |
| Nicholsons Enterprises Ltd | Hospitality | 2013 |
| Nodoubledutch Ltd | Real estate | 2019 |
| Novax Trading Limited | Administrative & support | 2016 |
| Novoboats Limited | Manufacturing | 2012 |
| Old Hospital Hub Limited | Real estate | 2019 |
| Osmer & Company Ltd | Professional & scientific | 2021 |
| Paranol Limited | Real estate | 1961 |
| Paul Bradley Ltd | Professional & scientific | 2020 |
| Pegham LJR Limited | Real estate | 2020 |
| Phipco Limited | Financial services | 2024 |
| Pirapora UK Limited | Professional & scientific | 1999 |
| Puritan Values Limited | Wholesale & retail | 2004 |
| R J Home Improvements Limited | Construction | 2005 |
| Randolph Hotel Group Holdings Limited | Financial services | 2025 |
| REJUVEN8 Southwold Limited | Other services | 2023 |
| Reydon (St.George's Square) Management Company Limited | Households | 2005 |
| Reydon Handyman Ltd | Construction | 2022 |
| Rissemere Limited | Professional & scientific | 2012 |
| RJB Electrical (Southwold) Ltd | Construction | 2020 |
| RS75 Limited | Hospitality | 2017 |
| Rudd Hotels & Restaurants Ltd | Hospitality | 2014 |
| S R 2024 Ltd | Hospitality | 2024 |
| Sail Southwold Limited | Transport & logistics | 2001 |
| Saturday Publishing Ltd | Information & communication | 2016 |
| Saturn Services Limited | Public administration | 2025 |
| Scnd Commerce Ltd | Wholesale & retail | 2025 |
| Scott Knights Limited | Other services | 2026 |
| Shardalows Limited | Professional & scientific | 1961 |
| Sign-Design-X LP | | 2014 |
| Silkline Decorating Limited | Construction | 2003 |
| South Green Design Limited | Professional & scientific | 2017 |
| Southdon Holdings Limited | Financial services | 2025 |
| Southwold and Aldeburgh Theatre Ltd | Education | 2019 |
| Southwold Carpets, Curtains and Blinds Limited | Wholesale & retail | 2005 |
| Southwold Common Developments Limited | Construction | 2005 |
| Southwold Film Society | Education | 2000 |
| Southwold Golf Club Limited | Arts & recreation | 2026 |
| Southwold Holdings Limited | Real estate | 2015 |
| Southwold Jewellers Limited | Extraterritorial | 2011 |
| Southwold Millennium Foundation | Health & social care | 2021 |
| Southwold Millennium Meadow Car Park Limited | Transport & logistics | 2021 |
| Southwold Oyster Company Ltd | Wholesale & retail | 2020 |
| Southwold Press Limited | Manufacturing | 2003 |
| Southwold Railway Company Limited | Transport & logistics | 2016 |
| Southwold Railway Trust | Arts & recreation | 2006 |
| Southwold Sailors' Reading Room Association | Other services | 2013 |
| Space Southwold Ltd | Construction | 2026 |
| Spring Design and Advertising Limited | Professional & scientific | 2005 |
| Spunyarns Limited | Wholesale & retail | 2013 |
| ST. Edmunds Court (Southwold) Limited | Households | 1980 |
| Sterling Sturrock Management Limited | Real estate | 2014 |
| Sunset Management Company (Southwold) Limited | Households | 2005 |
| T Partridge Electrical Ltd | Construction | 2019 |
| Taylor & SON Builders Limited | Construction | 2004 |
| Taylor Landscape Developments Ltd | Administrative & support | 2025 |
| THE Amber Room Limited | Extraterritorial | 1995 |
| THE Amber Shop Limited | Extraterritorial | 1998 |
| THE Black Olive Delicatessen Southwold Limited | Hospitality | 2005 |
| THE Blue Collective Ltd | Professional & scientific | 2025 |
| THE Crab and Oyster Ltd | Wholesale & retail | 2021 |
| THE Housekeeping Company Limited | Administrative & support | 2021 |
| THE Multi Piano Factory Ltd | Arts & recreation | 2024 |
| THE Nightingale Heath Management Company Limited | Real estate | 2003 |
| THE Pickled Kipper Ltd | Hospitality | 2024 |
| THE Randolph Hotel (Southwold) Limited | Hospitality | 2015 |
| THE Red Lion (Southwold) Ltd | Hospitality | 2017 |
| THE Sigsworth Partnership Ltd | Professional & scientific | 2012 |
| THE Walberswick Tuck Shop Ltd | Wholesale & retail | 2025 |
| The-Vyne Health Insights Ltd | Public administration | 2025 |
| Theatre East Ltd | Arts & recreation | 2026 |
| Tina Sivyer Limited | Professional & scientific | 2013 |
| Tiny House Ltd | Real estate | 2026 |
| Tobin Plant Equipment Ltd | Construction | 2026 |
| Tolleshunt East Green Limited | Real estate | 2020 |
| Tolleshunt Limited | Financial services | 1990 |
| Tolleshunt Properties Limited | Real estate | 2019 |
| Tolleshunt Trinity Limited | Hospitality | 2023 |
| TT Affiliate Academy Limited | Education | 2024 |
| Ukge Limited | Wholesale & retail | 2003 |
| Visible Edge Limited | Construction | 2005 |
| Whelley Properties Limited | Real estate | 1965 |
| Whiting & Howe Limited | Construction | 2002 |
| Woodlands Holdings (Southwold) Limited | Construction | 2010 |
| Yellow HAT 22 Limited | Professional & scientific | 2022 |