| THEFIVES5 Limited | Professional & scientific | 2023 |
| Themelios Holdings Ltd | Real estate | 2024 |
| Thempc Ltd | Professional & scientific | 2013 |
| Thempc Property Limited | Real estate | 2017 |
| Therapy Massage Ltd | Health & social care | 2022 |
| Thermagroup Ltd | Manufacturing | 1997 |
| Thermatool Europe Limited | Manufacturing | 2006 |
| Thermo King Fleet Solutions Limited | Financial services | 1956 |
| Thermozone Limited | Administrative & support | 1994 |
| Theshack Limited | Professional & scientific | 2017 |
| Theta Media Limited | Information & communication | 2026 |
| Thevendria Properties Limited | Real estate | 2023 |
| Thewillingbeauty Ltd | Real estate | 2019 |
| They Don'T Come With a Manual Ltd | Information & communication | 2025 |
| Thian Enterprises Limited | Hospitality | 2006 |
| Think Architecture Consultants Limited | Professional & scientific | 2013 |
| Third Bounce Limited | Administrative & support | 2009 |
| Third EYE Digital Security Ltd | Information & communication | 2025 |
| Tholcada Ltd | Wholesale & retail | 2023 |
| Thomas House (Overton) Ltd | Real estate | 2023 |
| Thomas.Crouch Ltd | Households | 2025 |
| Thor Leasehold Ltd | Households | 2016 |
| Thornbury Pickedmoor Development LLP | | 2023 |
| Thornton's Connection Limited | Health & social care | 2012 |
| Thorpe Laboratories Limited | Manufacturing | 2003 |
| Thoughtbridge Consulting Ltd | Professional & scientific | 2013 |
| THR Consultancy Ltd | Administrative & support | 2026 |
| Thread and Toast Ltd | Hospitality | 2025 |
| Three Little Birds LPS Limited | Financial services | 2021 |
| Three Little Birds Nurseries Holdings Ltd | Financial services | 2019 |
| Three Little Birds Nurseries Limited | Education | 2019 |
| Thriive Ltd | Hospitality | 2023 |
| Thrive Care Solutions Ltd | Administrative & support | 2023 |
| Thrive Online Global Ltd | Professional & scientific | 2025 |
| Thrive With Jayne Ltd | Health & social care | 2022 |
| Thunder Road Consultancy Limited | Information & communication | 2024 |
| Tiac Limited | Wholesale & retail | 2024 |
| TIC Creative Ltd | Professional & scientific | 2020 |
| Tickety BOO Teeth Limited | Health & social care | 2021 |
| Ticklaber Consulting Limited | Professional & scientific | 2025 |
| Tidy Time Franchising Ltd | Other services | 2022 |
| Tidy Time Group Ltd | Financial services | 2022 |
| Tier 1 Renovations Limited | Construction | 2023 |
| Tiffanystore Ltd | Wholesale & retail | 2026 |
| Tigara Ltd | Construction | 2025 |
| Tigershark Ventures Ltd | Wholesale & retail | 2014 |
| Tigris Health Limited | Health & social care | 2016 |
| Tije Properties Ltd | Real estate | 2023 |
| Tilage Limited | Construction | 2019 |
| Tilby Limited | Construction | 2005 |
| Tillow Ltd | Construction | 2024 |
| TIM Davey Limited | Construction | 2003 |
| TIM Parkes Design Ltd | Professional & scientific | 2025 |
| Timbers & Lychpit Ltd | Education | 2012 |
| Time & Precision (Sales) Limited | Manufacturing | 1963 |
| Time Accountancy Limited | Professional & scientific | 2005 |
| Timsun Services Limited | Health & social care | 2011 |
| TIN Shed Scenery Ltd | Arts & recreation | 2024 |
| Tinomuda Limited | Health & social care | 2026 |
| Tiny Steps Pre-School Limited | Health & social care | 2019 |
| TJ Francis Builders Ltd | Construction | 2015 |
| TJL Homes Ltd | Real estate | 2025 |
| TJM Tech Ltd | Information & communication | 2026 |
| TK Guitars Ltd | Manufacturing | 2020 |
| TKD24 Limited | Arts & recreation | 2020 |
| TL Fire Limited | Construction | 2010 |
| TM Orchard Estates Limited | Real estate | 2025 |
| Tmarinov Repairs Limited | Other services | 2025 |
| TMB Finance Limited | Financial services | 2023 |
| TMC Health Limited | Public administration | 2022 |
| Tmgf Company Ltd | Wholesale & retail | 2022 |
| TMH Commercial Limited | Wholesale & retail | 2023 |
| TMH Lettings Limited | Real estate | 2021 |
| TMK Health Ltd | Health & social care | 2024 |
| TNC Electronics Limited | Manufacturing | 1999 |
| TNG Ltd | Wholesale & retail | 2018 |
| Tnwc 2011 Ltd | Professional & scientific | 2011 |
| Toast Global Limited | Real estate | 2020 |
| Today`S Local Limited | Wholesale & retail | 2006 |
| Toga Properties Limited | Real estate | 2024 |
| Togwell Property Holdings Ltd | Real estate | 2026 |
| Tokyo Sushi Limited | Wholesale & retail | 2024 |
| Tolado. Limited | Professional & scientific | 2019 |
| TOM Bennett Editorial Ltd | Information & communication | 2021 |
| TOM Driving Ltd | Transport & logistics | 2026 |
| TOM Hopkins Codes Ltd | Information & communication | 2025 |
| Tomarkcareplus Ltd | Health & social care | 2025 |
| Tomato Sustainables Limited | Professional & scientific | 2024 |
| TOMEX4U Ltd | Transport & logistics | 2019 |
| Tomorrow IS Another Day Ltd | Wholesale & retail | 2021 |
| Toms Electrical Contractors Ltd | Manufacturing | 2011 |
| Toni Hair Ltd | Other services | 2011 |
| Tononoka Limited | Other services | 2015 |
| Tony Green Plumbing & Heating Ltd | Professional & scientific | 2013 |
| Tooth and Care Ltd | Health & social care | 2024 |
| Top London Limited | Extraterritorial | 2023 |
| Top MOM Digital Limited | Wholesale & retail | 2024 |
| Top Notch Building Services Limited | Construction | 2007 |
| Top Notch Interiors Ltd | Wholesale & retail | 2006 |
| Top of the Town Studios and Gallery C.I.C. | Health & social care | 2019 |