| TNS AI Services Ltd | Information & communication | 2026 |
| TNS Investment Ltd | Administrative & support | 2021 |
| TNS Restaurants Limited | Hospitality | 2024 |
| TNS Retail Ltd | Wholesale & retail | 2019 |
| TO the Big Kebab Ltd | Construction | 2024 |
| TO the Stars Ltd | Health & social care | 2019 |
| Toad Hall Developers Ltd | Real estate | 2026 |
| Tobbieandco Limited | Wholesale & retail | 2013 |
| Tobee Oyeleye Limited | Professional & scientific | 2019 |
| Toby&Dia Ltd | Transport & logistics | 2025 |
| Toca Building Ltd | Construction | 2015 |
| Tochlyn Limited | Wholesale & retail | 2025 |
| Tocor Ltd | Information & communication | 2023 |
| Tocora Ltd | Health & social care | 2026 |
| Todaes Services Limited | Administrative & support | 2018 |
| Todate Property Limited | Real estate | 2019 |
| Todate Solutions Limited | Information & communication | 2014 |
| Toddle About MK & Bedford Ltd | Education | 2023 |
| Toft Green Developments Limited | Construction | 2017 |
| TOG Orkis CIC | Hospitality | 2022 |
| TOG Support Services Limited | Administrative & support | 2022 |
| Together WE Go Further Ltd | Administrative & support | 2017 |
| Together WE Part Ltd | Professional & scientific | 2023 |
| Togetherasfamily Limited | Health & social care | 2020 |
| Togovan Limited | Wholesale & retail | 2019 |
| TOH22 Linguistic Consultancy Limited | Professional & scientific | 2019 |
| Tokatlian Ltd | Health & social care | 2020 |
| Tokem Services Limited | Administrative & support | 2014 |
| Tokidoki Limited | Information & communication | 2011 |
| Tokun Ltd | Information & communication | 2022 |
| Tokyo Bay UK Limited | Wholesale & retail | 2023 |
| Toles Multinational Business Ltd | Professional & scientific | 2025 |
| Tolex Ventures Limited | Health & social care | 2025 |
| Tollgate Residents Company Limited | Households | 1987 |
| Tollgate Square NO.1 Residents Company Limited | Households | 1987 |
| Tollgate Square NO.2 Residents Company Limited | Households | 1987 |
| Tollgate Square NO.3 Residents Company Limited | Households | 1987 |
| Tollgate Square NO.4 Residents Company Limited | Households | 1987 |
| Tollgate Square NO.5 Residents Company Limited | Households | 1987 |
| Tollywood Thoughts Limited | Information & communication | 2022 |
| Tolson Trading Ltd | Extraterritorial | 2015 |
| Tolu Wusu Ltd | Administrative & support | 2022 |
| TOM Davies Bespoke Eyewear Limited | Wholesale & retail | 2007 |
| TOM Halfpenny Data Ltd | Information & communication | 2025 |
| Tomfag LLP | | 2010 |
| Tommy Refurb Ltd | Manufacturing | 2014 |
| Tommy Trans Ltd | Transport & logistics | 2016 |
| Tomogroup Ltd | Wholesale & retail | 2025 |
| Tomoka Casks Limited | Wholesale & retail | 2019 |
| Tomoka Fine and Rare Limited | Wholesale & retail | 2012 |
| Tomp International Limited | Professional & scientific | 2008 |
| Tomsim Limited | Professional & scientific | 2014 |
| Tomstacey Ltd | Professional & scientific | 2024 |
| Tomtim Limited | Real estate | 2018 |
| Tomworld Limited | Real estate | 2010 |
| Tonca Property Lettings and Maintenance Limited | Real estate | 2022 |
| Tonetini Ltd | Wholesale & retail | 2025 |
| Tong Dinner Ltd | Hospitality | 2021 |
| Tonga & Tonga Limited | Other services | 2015 |
| Tonia Galati Consulting Limited | Professional & scientific | 2018 |
| Tonny Logistics Ltd | Transport & logistics | 2024 |
| Tony and RAY Limited | Real estate | 2024 |
| Tony Kirwan Contractors Limited | Construction | 1992 |
| Tony Management Ltd | Construction | 2017 |
| Tony Talks Money Limited | Information & communication | 2024 |
| Toobee Limited | Professional & scientific | 2015 |
| Tools 4 Trade Limited | Wholesale & retail | 2004 |
| Tools for Self Reliance (Milton Keynes) | Education | 1993 |
| Toorank UK Limited | Wholesale & retail | 1998 |
| Tooth Wellness Ltd | Health & social care | 2025 |
| Toots Hibbert Publishing Limited | Arts & recreation | 1999 |
| Top Accounting Limited | Transport & logistics | 2022 |
| Top BMD Ltd | Construction | 2024 |
| Top Chiropractic Birmingham Limited | Health & social care | 2024 |
| Top Chiropractic Edinburgh Ltd | Health & social care | 2025 |
| Top Chiropractic Newcastle Limited | Health & social care | 2024 |
| Top Class Delivery Ltd | Transport & logistics | 2015 |
| Top Diner Limited | Hospitality | 2022 |
| Top END Village Stores Limited | Wholesale & retail | 2002 |
| Top Home Cleaning Ltd | Administrative & support | 2016 |
| Top Magic Limited | Wholesale & retail | 2023 |
| Top Renting Ltd | Real estate | 2023 |
| Top Sarv Consultancy Limited | Information & communication | 2016 |
| Top Shield Networks Limited | Administrative & support | 2025 |
| Top Smart Electrical Ltd | Construction | 2026 |
| Top Tools Limited | Wholesale & retail | 2016 |
| Top UK Services Ltd | Education | 2021 |
| Top Wheel Repair Ltd | Wholesale & retail | 2023 |
| Top-Notch Laboratory Ltd | Health & social care | 2025 |
| Topaz Investments LLP | | 2009 |
| Topchiro Aylesbury Limited | Health & social care | 2024 |
| Topchiro Poole Limited | Health & social care | 2026 |
| Topdrill Ltd | Construction | 2006 |
| Topendology Ltd | Information & communication | 2017 |
| Topher Software Limited | Information & communication | 2017 |
| Topline Components Limited | Administrative & support | 2002 |
| Topnotch Academy Limited | Public administration | 2023 |
| Toppes Ltd | Construction | 2026 |
| Topsalescloud Ltd | Information & communication | 2025 |
| Toptech Accessories Limited | Other services | 2023 |