| Sylvan Works Ltd | Manufacturing | 2020 |
| Sylvarum Consulting Ltd. | Administrative & support | 2024 |
| Symbios Health Limited | Health & social care | 2020 |
| Symbolsend Ltd | Information & communication | 2019 |
| Symonds Solicitors Limited | Professional & scientific | 2013 |
| Symons Corporations Ltd | Real estate | 2024 |
| Syncytium Health Ltd | Health & social care | 2024 |
| Synergi Projects Ltd | Professional & scientific | 2022 |
| Synergy (Plymouth) Limited | Professional & scientific | 2015 |
| Synergy Health Solutions Ltd | Health & social care | 2015 |
| Synergy Technical Services Ltd | Professional & scientific | 2018 |
| Systemec Limited | Transport & logistics | 1972 |
| Szcreations Ltd | Wholesale & retail | 2025 |
| SZN Services Ltd | Administrative & support | 2020 |
| T & C Decorators Ltd | Construction | 2015 |
| T & C Hot WOK Ltd | Hospitality | 2022 |
| T & F Decorators Ltd | Construction | 2014 |
| T & G Traders Ltd | Wholesale & retail | 2023 |
| T & J C.A.R.E Hub Ltd | Health & social care | 2026 |
| T & W Body Holdings Limited | Financial services | 2020 |
| T a Limited | Professional & scientific | 2002 |
| T and C Metal Limited | Wholesale & retail | 2019 |
| T C Brickwork (SW) Ltd | Construction | 2020 |
| T G K Carpentry Services Limited | Construction | 2026 |
| T Gilmore Properties Ltd | Real estate | 2021 |
| T Hancock Construction Ltd | Construction | 2023 |
| T Harding Properties Limited | Real estate | 2025 |
| T J R Developments Limited | Construction | 2018 |
| T James Management Ltd | Professional & scientific | 2024 |
| T K Pipework Services Limited | Administrative & support | 2014 |
| T Y M Soft Limited | Transport & logistics | 2017 |
| T&J Byrne Residential Property Limited | Real estate | 2022 |
| T&L Homes Ltd | Real estate | 2021 |
| T&M Fishing Ltd | Agriculture & fishing | 2022 |
| T&M Property Developments Ltd | Real estate | 2024 |
| T&S Food and Wine Ltd | Wholesale & retail | 2023 |
| T.A.B Roofing Contractors Limited | Construction | 2024 |
| T.E.J. Heating (Plymouth) Limited | Construction | 1989 |
| T.G Ground Services & Plant Hire Limited | Construction | 2022 |
| T.G.M.A Pro Food Limited | Hospitality | 2016 |
| T.I.M. Marine Limited | Public administration | 2012 |
| T10 Admin Services Ltd | Administrative & support | 2026 |
| T2 Management Limited | Other services | 2018 |
| Tabadek Limited | Health & social care | 2026 |
| Taberna Stores Limited | Wholesale & retail | 2024 |
| Tactics, Command and Leadership Ltd | Administrative & support | 2015 |
| Tadah Design Ltd | Professional & scientific | 2013 |
| Tadtech Ltd | Information & communication | 2015 |
| TAG Financial Planning Limited | Financial services | 2017 |
| TAG Motorsport Ltd | Wholesale & retail | 2020 |
| Tailor Practitioners Trimmings Limited | Wholesale & retail | 2025 |
| Tailored AI Ltd | Information & communication | 2024 |
| Tailored Furnishings Limited | Manufacturing | 2016 |
| Tailored Heat Ltd | Construction | 2015 |
| Tailored Wealth Financial Planning Ltd | Financial services | 2023 |
| Tails UP Limited | Hospitality | 2021 |
| Take a Part Trading Limited | Professional & scientific | 2022 |
| Take ME ( Plymouth ) Ltd | Transport & logistics | 2021 |
| Talaat Private Gynaecology Ltd | Health & social care | 2016 |
| Talamo Limited | Information & communication | 2021 |
| Talbott & Tennet Limited | Wholesale & retail | 2008 |
| Talklight Limited | Wholesale & retail | 1981 |
| Tall Trees (South West) Limited | Health & social care | 1999 |
| Talpa Office Products Limited | Wholesale & retail | 2001 |
| Tamar & Provincial Estates Limited | Construction | 1959 |
| Tamar Adventures Limited | Arts & recreation | 2011 |
| Tamar Analytical Limited | Professional & scientific | 2003 |
| Tamar Caravans & Motorhomes Ltd | Wholesale & retail | 2004 |
| Tamar Carpentry Ltd | Manufacturing | 2023 |
| Tamar Community Business Limited | Hospitality | 2000 |
| Tamar Doors Limited | Manufacturing | 2024 |
| Tamar Electronics Limited | Manufacturing | 2008 |
| Tamar Estates (South West) Limited | Construction | 2015 |
| Tamar Health Ltd | Health & social care | 2024 |
| Tamar Heath Ltd | Real estate | 2023 |
| Tamar Holdings SW Ltd | Real estate | 2024 |
| Tamar Homes Ltd | Real estate | 2012 |
| Tamar HR Limited | Administrative & support | 2005 |
| Tamar Labels Limited | Manufacturing | 1995 |
| Tamar Leisure Holdings Ltd | Financial services | 2022 |
| Tamar Management Co Limited | Extraterritorial | 2002 |
| Tamar Petcare Limited | Professional & scientific | 2025 |
| Tamar Plastics Ltd | Wholesale & retail | 2026 |
| Tamar Scaffolding Limited | Construction | 2007 |
| Tamar Terrace Management Company Limited | Real estate | 2007 |
| Tamar Tractors Limited | Transport & logistics | 2006 |
| Tamar Travel Management Limited | Administrative & support | 2018 |
| Tamar Valley Crematorium Limited | Other services | 2021 |
| Tamar Valley Training Ltd | Education | 2022 |
| Tamar Valley View Residents Company Limited | Households | 2000 |
| Tamar View Community Complex Ltd | Real estate | 2000 |
| Tamar View Residents Association Limited | Households | 1991 |
| Tamar Water Solutions Ltd | Administrative & support | 2024 |
| Tamara House Care Home Limited | Health & social care | 2009 |
| Tamarind Software Ltd | Information & communication | 2006 |
| Tamarside Properties Limited | Real estate | 2025 |
| Tamartech Ltd | Financial services | 2020 |
| Tamerton (Fraser & Linton) Residents Company Limited | Households | 2003 |
| Tamerton Heights Residents Company Limited | Households | 1999 |
| Tamerton Karate Club CIC | Other services | 2025 |