| Swift Access Health Limited | Health & social care | 2025 |
| Swift Access Health Medical Limited | Health & social care | 2025 |
| Swiftqube Limited | Information & communication | 2023 |
| Syarc Ltd | Information & communication | 2025 |
| Sylvan Finance Limited | Administrative & support | 2020 |
| Symposium Pubs Ltd | Hospitality | 2026 |
| Synaflex Solutions Limited | Information & communication | 2014 |
| System One Limited | Wholesale & retail | 1988 |
| Szekai Limited | Hospitality | 2024 |
| T&M Tools and Fixings Hire and Sale Ltd | Construction | 2017 |
| Take 2 AV Ltd | Construction | 2026 |
| Tamesis Construction Limited | Construction | 2023 |
| Tamesis Properties Limited | Construction | 2020 |
| Tanners Court Management Company Limited | Households | 1982 |
| Tanya Couture Boutique Ltd | Extraterritorial | 2006 |
| Tanzco Limited | Information & communication | 2023 |
| Taranaki Contracting Services Limited | Professional & scientific | 2003 |
| Taurus Auto Electrics Limited | Wholesale & retail | 2003 |
| Tavern Townhouse Ltd | Hospitality | 2024 |
| Taylor Unus Limited | Professional & scientific | 2017 |
| TCD (Vineyard) Limited | Real estate | 2014 |
| Tcup Consulting Limited | Arts & recreation | 2010 |
| Team Menus Limited | Information & communication | 1999 |
| Team Resourcing (Holdings) Ltd | Financial services | 2024 |
| Team Resourcing Limited | Administrative & support | 1999 |
| Teamgeist Limited | Wholesale & retail | 2004 |
| Tech Performance Limited | Professional & scientific | 2024 |
| Technical and Management Services Limited | Transport & logistics | 1969 |
| TED James Limited | Other services | 2013 |
| Tekstate Limited | Administrative & support | 2025 |
| Temple Midco Limited | Other services | 2017 |
| Temple Topco Limited | Other services | 2017 |
| Temporal Consulting Limited | Other services | 2003 |
| Tempus Group Holdings Limited | Professional & scientific | 2026 |
| Tempus Healthcare Ltd | Health & social care | 2024 |
| Termhouse (Rosehill House) Management Limited | Households | 1989 |
| Terry's Auto Traders Limited | Wholesale & retail | 2024 |
| TFS Retreats Agency Services Ltd | Administrative & support | 2021 |
| TFS Serviced Accommodation LLP | | 2018 |
| Thaili Ltd | Hospitality | 2024 |
| Thames Court (Abingdon) Residents Association Limited | Households | 1997 |
| Thames Gastro Limited | Health & social care | 2020 |
| Thames Valley Balloons Limited | Arts & recreation | 2003 |
| Thames Valley Design LED Construction Ltd | Construction | 2025 |
| Thames-Side Court Estate Limited | Households | 2020 |
| Thameside Removals Ltd | Transport & logistics | 2024 |
| Thamesview Tyres Ltd | Wholesale & retail | 2003 |
| THE Abbott Partnership Lettings Limited | Real estate | 2019 |
| THE Abbott Partnership Limited | Real estate | 2004 |
| THE Academy of Alchemy Limited | Education | 2024 |
| THE Alpine Circle Limited | Administrative & support | 2026 |
| THE Alpine Standard Limited | Administrative & support | 2026 |
| THE Ark#Safe Space CIC | Health & social care | 2014 |
| THE Audax Generation Ltd | Professional & scientific | 2021 |
| THE Authentic Cruise Company Limited | Administrative & support | 2023 |
| THE Barbour Partnership Limited | Professional & scientific | 2017 |
| THE Beaulieu House (Binfield) Management Company Limited | Real estate | 2000 |
| THE Beeches Communal Area Limited | Households | 2026 |
| THE Beeches Sewer Management Company (Lower Shiplake) Limited | Households | 2022 |
| THE Brewery (Abingdon) Management Company Limited | Households | 2000 |
| THE Broadway (Didcot) Management Company Limited | Households | 1988 |
| THE Bull Nettlebed (NO. 2) Limited | Households | 1999 |
| THE Bump Class Limited | Education | 2013 |
| THE Carlings Orchard Management Company Limited | Households | 1998 |
| THE Cctv User Group Limited | Other services | 1996 |
| THE Chiltern Centre Limited | Health & social care | 2003 |
| THE Chiltern Flour Company Ltd | Manufacturing | 2026 |
| THE Cloisters (High Wycombe) Limited | Households | 2019 |
| THE Crop Candle Company Ltd | Wholesale & retail | 2020 |
| THE Data Support Agency Limited | Professional & scientific | 2017 |
| THE Davidson Group Limited | Financial services | 2017 |
| THE Douglas Watson Studio Limited | Manufacturing | 2004 |
| THE Dovetail Partnership Limited | Professional & scientific | 2010 |
| THE Emotions LAB Ltd | Education | 2024 |
| THE Employee Benefits Corporation Limited | Professional & scientific | 2017 |
| THE Employment Law Partnership Limited | Professional & scientific | 2012 |
| THE Fine Art Society Limited | Wholesale & retail | 1876 |
| THE Flints Management Limited | Households | 2022 |
| THE Floral Garden Centre Limited | Wholesale & retail | 2017 |
| THE Flower TAP Ltd | Wholesale & retail | 2025 |
| THE Flower Union Ltd | Wholesale & retail | 2021 |
| THE Founders Network Global Ltd | Information & communication | 2025 |
| THE Gland of Brothers CIC | Health & social care | 2023 |
| THE Good Customer Consulting Limited | Professional & scientific | 2024 |
| THE Good Kitchen Limited | Wholesale & retail | 2015 |
| THE Green Bough Company Limited | Wholesale & retail | 2009 |
| THE Growth Department Limited | Professional & scientific | 2018 |
| THE Growth House Ltd | Professional & scientific | 2018 |
| THE Hamilton Marketing Consultancy Limited | Professional & scientific | 2025 |
| THE Henley Coaching Partnership Limited | Professional & scientific | 2011 |
| THE Henley Distillery Limited | Manufacturing | 2020 |
| THE Henley Golf Club Limited | Administrative & support | 2016 |
| THE Henley Grapevine Limited | Extraterritorial | 1998 |
| THE Henley Mortgage Company Ltd | Financial services | 2023 |
| THE Henley Wellbeing Centre Ltd | Health & social care | 2026 |
| THE Hermit Comedy Ltd | Arts & recreation | 2026 |
| THE Hermitage Freehold Company Limited | Households | 2016 |
| THE HFT Organisation Ltd | Administrative & support | 2025 |
| THE Huntley RTM Company Limited | Extraterritorial | 2024 |
| THE Hyde Ventures Ltd | Professional & scientific | 2007 |