| Supernova Capital Assets Limited | Financial services | 2021 |
| Supply Chain Link Ltd | Administrative & support | 2015 |
| Supply Chain People Ltd | Administrative & support | 2015 |
| SUPPLYCHAIN21 Limited | Transport & logistics | 2009 |
| Support Gruppen LLP | | 2013 |
| Supreme Comfort Ltd | Wholesale & retail | 2023 |
| Surge Element Limited | Wholesale & retail | 2014 |
| Surveymyhome.Co.Uk Ltd | Information & communication | 2012 |
| Sustainability Consulting and Training Ltd | Professional & scientific | 2026 |
| Sutterton Holdings Ltd | Professional & scientific | 2023 |
| SVG Quarters Ltd | Real estate | 2026 |
| Swade Digital UK Ltd | Administrative & support | 2025 |
| Swancar of Loughborough Ltd | Wholesale & retail | 2021 |
| Swancar.Com Ltd | Wholesale & retail | 2021 |
| Sweet Naga Chilli Ltd | Hospitality | 2019 |
| Swift FOX Consultancy Ltd | Professional & scientific | 2019 |
| Swinfen Farms Ltd | Agriculture & fishing | 2017 |
| Swordfish Media Limited | Professional & scientific | 2013 |
| SWP Schools Limited | Professional & scientific | 2023 |
| Sycamore Care Providers Limited | Health & social care | 2023 |
| Sylab Scientific Ltd | Manufacturing | 2023 |
| Symcirrus Limited | Wholesale & retail | 2010 |
| Synergy Site Services Limited | Construction | 2016 |
| System-Matic Limited | Manufacturing | 2012 |
| T J Thornton Limited | Wholesale & retail | 2007 |
| T P Commercial Properties Limited | Real estate | 2025 |
| T R C Contracts Limited | Construction | 1998 |
| T&H Digital Ltd | Information & communication | 2022 |
| T&J Community Support Services Ltd | Health & social care | 2025 |
| T. Dennis Property Developments Limited | Real estate | 2001 |
| T.M.T. Holdings Limited | Administrative & support | 1972 |
| T2 Maintenance Ltd | Construction | 2018 |
| TA Controls Ltd | Information & communication | 2018 |
| TA Corporate Finance Limited | Professional & scientific | 2016 |
| TAB Battery UK Limited | Manufacturing | 2011 |
| TAB UK Holdings Limited | Financial services | 2016 |
| TAG Berry Audit Limited | Professional & scientific | 2024 |
| Tailored Learning Resources Limited | Education | 2006 |
| Taken Consulting Ltd | Professional & scientific | 2025 |
| Talentarc Ltd | Professional & scientific | 2024 |
| Talentman Ltd | Professional & scientific | 2020 |
| Tandem Ellis Ltd | Financial services | 2021 |
| Tangible Results Services Limited | Professional & scientific | 2000 |
| Tangled Ltd | Hospitality | 2011 |
| Tantum Limited | Financial services | 2015 |
| Tanya Sweeten Ltd | Construction | 2024 |
| Taoshuang Guardianship Limited | Education | 2023 |
| Tarian Financial Planning Limited | Financial services | 2026 |
| Taste DOT Social Ltd | Hospitality | 2025 |
| Taste of India Rothwell Ltd | Hospitality | 2024 |
| Taycode Ltd | Administrative & support | 2016 |
| Taylor Squared Solutions Limited | Administrative & support | 2022 |
| TC Stephen Limited | Real estate | 2024 |
| TCM Mental Health Assessment Limited | Health & social care | 2015 |
| Techline Roofing & Driveways Ltd | Construction | 2018 |
| Technical Services Consulting Limited | Professional & scientific | 2018 |
| Technical Sports Management Ltd | Arts & recreation | 2004 |
| Technisteel Limited | Manufacturing | 2019 |
| Technophilia Limited | Information & communication | 1987 |
| Techsport Engineering Ltd | Administrative & support | 2017 |
| Tecma (UK) Ltd | Manufacturing | 2002 |
| Tecno Services Ltd | Professional & scientific | 2022 |
| Teepees and Tents Ltd | Arts & recreation | 2017 |
| Terrace Hills Farm LLP | | 2010 |
| Tesa Developments Limited | Professional & scientific | 2018 |
| Teulu Creative & Consulting Services LLP | | 2025 |
| Tfcc Group Ltd | Extraterritorial | 2018 |
| TFN Harborough Limited | Other services | 2021 |
| TGW Limited | Construction | 2006 |
| THA Properties Ltd | Real estate | 2023 |
| Thames Records Ltd | Wholesale & retail | 2015 |
| THE Accountancy Group (TAG) Limited | Professional & scientific | 2024 |
| THE Angler Hospitality Company Limited | Hospitality | 2025 |
| THE Angler Oakham Limited | Hospitality | 2026 |
| THE Attic Hair Studio Limited | Other services | 2019 |
| THE Baby Hamper Company Limited Liability Partnership | | 2025 |
| THE Badgers DEN Group Ltd | Other services | 2025 |
| THE Badgers DEN Market Harborough Ltd | Other services | 2024 |
| THE Bakers Arms Ltd | Hospitality | 2025 |
| THE Birdsong Partnership Ltd | Professional & scientific | 2005 |
| THE Black Horse Foxton Limited | Hospitality | 2024 |
| THE Board Practice LLP | | 2010 |
| THE Book Guild Ltd | Information & communication | 2014 |
| THE Bottle Kicking Cider Company Limited | Manufacturing | 2010 |
| THE Business HUT Limited | Professional & scientific | 2016 |
| THE Cafe Group Limited | Hospitality | 2021 |
| THE Care Training Company Ltd | Education | 2020 |
| THE Chapel Great Bowden Management Limited | Households | 2021 |
| THE Clothing Foundry Limited | Wholesale & retail | 2012 |
| THE Code Clinic (Holding) Company Limited | Financial services | 2017 |
| THE Code Clinic Limited | Information & communication | 2002 |
| THE Content Marketing Team Ltd | Administrative & support | 2018 |
| THE Core Dance Company Ltd | Arts & recreation | 2022 |
| THE Dog Club Lubenham Limited | Other services | 2024 |
| THE Doodle Cloud Limited | Information & communication | 2013 |
| THE Duchess' Collection Ltd | Wholesale & retail | 2018 |
| THE Elite Suite Limited | Professional & scientific | 2018 |
| THE Engine Yard Cafe and Bistro Ltd | Hospitality | 2018 |
| THE Estate Experience Consultancy Ltd | Professional & scientific | 2025 |
| THE Fellowship Property Trust | Other services | 1927 |