| TCG Accounts Ltd | Professional & scientific | 2025 |
| TCG Awesomeness Ltd | Wholesale & retail | 2021 |
| TCM LOC Limited | Health & social care | 2022 |
| Tcnn Ltd | Information & communication | 2026 |
| Tcpw Risca Ltd | Wholesale & retail | 2025 |
| TD2 Rugby Ltd | Arts & recreation | 2023 |
| Tdsi Ltd | Transport & logistics | 2026 |
| TE J-Rae Ltd | Wholesale & retail | 2025 |
| Tea & Toast Management Limited | Administrative & support | 2015 |
| Tea and Toast Event Catering Limited | Hospitality | 2015 |
| Tea and Toast Festivals Limited | Hospitality | 2015 |
| Tea Planet Ltd | Wholesale & retail | 2026 |
| Teabag Productions Ltd | Hospitality | 2023 |
| Teach Yourself Driving Academy Ltd | Education | 2026 |
| Team Engineering Solutions Together Limited | Manufacturing | 2023 |
| Team GAS Ltd | Construction | 2017 |
| Team Titan Coaching Ltd | Education | 2024 |
| TEC Davies Construction Limited | Manufacturing | 2019 |
| Tech Bridge Outsourcing Ltd | Information & communication | 2025 |
| Tech Desk IT Limited | Professional & scientific | 2018 |
| Tech Repair Limited | Information & communication | 2007 |
| Techcount Limited | Wholesale & retail | 2024 |
| Techit Appit Ltd | Information & communication | 2023 |
| Technorm Limited | Information & communication | 2018 |
| Techygear Ltd | Information & communication | 2022 |
| Techzone Electrics Limited | Manufacturing | 2025 |
| TED Hopkins Limited | Manufacturing | 1989 |
| Teddy EVA Scents Ltd | Manufacturing | 2021 |
| Teddy Restaurants Limited | Hospitality | 2023 |
| Teds Farm Camping Limited | Hospitality | 2023 |
| Tedy Logistics Ltd | Transport & logistics | 2022 |
| Teebubbles Limited | Administrative & support | 2024 |
| Tegelbeckers Ltd | Manufacturing | 2013 |
| TEK Cloudsoul Ltd | Information & communication | 2024 |
| TEK Phluent Limited | Information & communication | 2024 |
| Tekir Marketing Ltd | Professional & scientific | 2018 |
| Tekton Civil Engineering Ltd | Construction | 2024 |
| Tekton Development Limited | Manufacturing | 2022 |
| Telegiants BPO Ltd | Professional & scientific | 2020 |
| Telehandler Ltd | Extraterritorial | 2013 |
| Telematix Ltd | Information & communication | 2023 |
| Telford & Co UK LLP | | 2015 |
| Telford Accountancy Services Limited | Professional & scientific | 2010 |
| Telford Chiropractic Limited | Health & social care | 2001 |
| Tellermate Holdings Limited | Professional & scientific | 2010 |
| Tellermate Limited | Manufacturing | 1980 |
| Telz Health Care and Logistics Ltd | Extraterritorial | 2023 |
| TEM Direct Ltd | Wholesale & retail | 2025 |
| Tempest Property Management Limited | Real estate | 2018 |
| Temple Meadow Holdings Limited | Financial services | 2021 |
| TEN Pearl Limited | Wholesale & retail | 2007 |
| Tenby House (Fishguard) Limited | Other services | 2002 |
| Tennant IP Limited | Other services | 2009 |
| Tennyson Rise RTM Company Limited | Households | 2018 |
| Tenstep Limited | Manufacturing | 2002 |
| Tenty Ltd | Administrative & support | 2021 |
| Terence a. Johnsey Limited | | 1958 |
| Terminator Clothing Ltd | Wholesale & retail | 1998 |
| Terra Telemetry Ltd | Manufacturing | 2026 |
| Terrado-Reardon Limited | Other services | 2019 |
| Terrasofta Products Limited | Manufacturing | 2010 |
| Testeve Global Concepts Ltd | Health & social care | 2023 |
| Textile Tribe Ltd | Wholesale & retail | 2024 |
| Textradeuk Ltd | Wholesale & retail | 2023 |
| TF Promotions Limited | Administrative & support | 2011 |
| TF15 Promotions Ltd | Arts & recreation | 2022 |
| TF3 Promotions Limited | Administrative & support | 2015 |
| TF3 Properties Limited | Real estate | 2021 |
| TG Howell & Sons (Holdings) Ltd | Financial services | 2022 |
| TG General Trading Ltd | Other services | 2022 |
| Tgdr IMC Ltd | Professional & scientific | 2018 |
| TGP Care Ltd | Health & social care | 2022 |
| Tgpragnell Limited | Manufacturing | 2023 |
| TGW Property Limited | Real estate | 2019 |
| TH & L Jones Limited | Wholesale & retail | 2006 |
| TH67 Promotions Ltd | Real estate | 2026 |
| Thai Bodyworx Ltd | Other services | 2025 |
| Thai by JA Ltd | Hospitality | 2026 |
| Thai District Ltd | Hospitality | 2026 |
| Thai Silk Ltd | Other services | 2025 |
| Thames Advisory Ltd | Real estate | 2019 |
| Thames Valley (Holdings) Limited | Financial services | 2013 |
| Thames Valley Construction & Civil Engineering Limited | Construction | 2004 |
| Thames Valley Construction and Concrete Structures Limited | Construction | 2008 |
| Thames Valley Construction Limited | Construction | 2012 |
| That Personal Touch Lawn & Garden Specialists Ltd | Administrative & support | 2025 |
| THE Adelaide Management Company Limited | Households | 2015 |
| THE Adhd-Dementia Diagnostics Centre Ltd Ltd | Public administration | 2025 |
| THE Aditus Group Ltd | Professional & scientific | 2026 |
| THE Airedale Lady Limited | Other services | 2023 |
| THE Airedale Lady RAW Limited | Wholesale & retail | 2023 |
| THE ALL Seeing I Ltd | Professional & scientific | 2021 |
| THE Assistant Girls Ltd | Public administration | 2023 |
| THE Ballroom Network Ltd | Arts & recreation | 2017 |
| THE Barber House IOW Ltd | Other services | 2026 |
| THE Beach Boutique Holidays Ltd | Administrative & support | 2022 |
| THE Beach Boutique Ltd | Administrative & support | 2025 |
| THE Beauty Bar Bristol Ltd | Other services | 2021 |
| THE Beauty Hub Pembrokeshire Limited | Other services | 2025 |
| THE BEE & Dragon Catering Company Limited | Hospitality | 2021 |