| TO BE Announced Ltd | Wholesale & retail | 2021 |
| TO BE Systems Limited | Professional & scientific | 2013 |
| Tobin F Ltd | Professional & scientific | 2021 |
| Tobisam Properties Limited | Real estate | 2020 |
| TOC Care Services Limited | Health & social care | 2019 |
| Toci Logistics Ltd | Transport & logistics | 2024 |
| Todd Creative Services Limited | Professional & scientific | 2007 |
| Toddler Sense Harlow Ltd | Health & social care | 2018 |
| Tofan Plastering Ltd | Construction | 2017 |
| TOG Clothing (UK) Limited | Wholesale & retail | 2014 |
| TOG Kitchenware Limited | Wholesale & retail | 2026 |
| Toil (Lodge Farm) Management Company Limited | Households | 2021 |
| Token Traxx Hold Co Ltd | Information & communication | 2022 |
| Token Traxx IP Limited | Information & communication | 2022 |
| Token Traxx Music Ltd | Information & communication | 2021 |
| Tokenized Properties Ltd | Real estate | 2022 |
| Tokhi Medical Limited | Health & social care | 2020 |
| Told Communications Ltd | Information & communication | 2023 |
| Tolo Carpets Ltd | Wholesale & retail | 2016 |
| Tolpits Garage Limited | Real estate | 1972 |
| TOM Pigott-Smith Ltd | Administrative & support | 2016 |
| TOM Veal Services Limited | Construction | 2023 |
| TOM Wood Project UK Ltd | Wholesale & retail | 2025 |
| Tom's Garden Services Limited | Other services | 2011 |
| Toma & Sons Ltd | Construction | 2024 |
| Toma Transport Limited | Transport & logistics | 2014 |
| Tomahawk Lettings Ltd | Real estate | 2026 |
| Tomeasure Ltd | Wholesale & retail | 2024 |
| Tomittsupplies Ltd | Wholesale & retail | 2020 |
| Tomo Industrial Park Ltd | Real estate | 2026 |
| Tomorrow NOW Partners Limited | Professional & scientific | 2019 |
| Tomorrow's Hope Media CIC | Professional & scientific | 2020 |
| Tomorrow's Warriors Trust | Arts & recreation | 2012 |
| Tomorrows Hope Foundation | Health & social care | 2022 |
| Tompo Consulting Limited | Information & communication | 2019 |
| Tomson Europe Limited | Other services | 1998 |
| Tomus Trans Limited | Construction | 2018 |
| Tonaoi Thai Therapy Ltd | Other services | 2025 |
| Tonic London Limited | Wholesale & retail | 2023 |
| Toniga Ltd | Professional & scientific | 2023 |
| Tony Devine Limited | Construction | 2012 |
| Tony G Electrical Ltd | Construction | 2024 |
| Tonys Best Hand Car Wash Ltd | Administrative & support | 2022 |
| Tooki's Limited | Wholesale & retail | 2024 |
| Tool Chest Tool and Plant Hire Ltd | Administrative & support | 2018 |
| TOONE00 Ltd | Wholesale & retail | 2025 |
| Toothache Solutions Ltd | Health & social care | 2016 |
| Toothfairy London Limited | Health & social care | 2010 |
| Toothful Limited | Health & social care | 2013 |
| Tooting Kebab and Chicken Ltd | Hospitality | 2026 |
| Top Choice Hire Limited | Wholesale & retail | 2023 |
| Top Deals Store Ltd | Wholesale & retail | 2021 |
| Top Down Trading and Suppliers Limited | Wholesale & retail | 2025 |
| Top Fence Limited | Construction | 2016 |
| Top Gear Logistics Ltd | Wholesale & retail | 2021 |
| Top Gear Motors (UK) Limited | Wholesale & retail | 2013 |
| Top Hair Link Ltd | Other services | 2017 |
| Top HAT Directories Ltd | Information & communication | 2012 |
| Top in Town Limited | Wholesale & retail | 2024 |
| Top Notch Hounds Ltd | Other services | 2018 |
| Top Notch Resin Ltd | Administrative & support | 2020 |
| Top One Limited | Real estate | 1993 |
| Top Phone Planet Ltd | Wholesale & retail | 2018 |
| Top Quality Cars Ltd | Wholesale & retail | 2023 |
| Top Quality Road Ltd | Construction | 2024 |
| Top Secret Investment Ltd | Financial services | 2025 |
| Top Tier Tyres Ltd | Wholesale & retail | 2026 |
| Top Vision Limited | Wholesale & retail | 1995 |
| Topaz Care Services Ltd | Health & social care | 2016 |
| Topaz Property Investments Ltd | Real estate | 2025 |
| Topbrand Promotions Limited | Wholesale & retail | 2009 |
| Topcatt Consulting Ltd. | Administrative & support | 2015 |
| Topchoice Tyres Ltd | Administrative & support | 2019 |
| Topcom Security Ltd | Administrative & support | 2011 |
| Topcons Design Ltd | Construction | 2022 |
| Topenkin Limited | Education | 2014 |
| Topfloor Lettings Limited | Real estate | 2022 |
| Tophospitality Ltd | Professional & scientific | 2024 |
| Topia Life Sciences Holdings Limited | Financial services | 2025 |
| Topia Medtech Holdings Limited | Financial services | 2025 |
| Topia Medtech Limited | Professional & scientific | 2025 |
| Topia Pharma Intelligence Holdings Limited | Financial services | 2025 |
| Topia Pharma Intelligence Limited | Information & communication | 2025 |
| Topline Store Ltd | Wholesale & retail | 2019 |
| Toplinesecuritygb Ltd | Administrative & support | 2021 |
| Topman Contractors Ltd | Construction | 2025 |
| Topnourish Limited | Hospitality | 2023 |
| Topo M Surveys Ltd | Wholesale & retail | 2018 |
| Toppm Ltd | Other services | 2025 |
| Topskill Builders Ltd | Construction | 2023 |
| Toptrendz Limited | Wholesale & retail | 2011 |
| Torac Ltd | Construction | 2019 |
| Torah & Chesed (BH) Limited | Health & social care | 1978 |
| Torberg Film Ltd | Information & communication | 2026 |
| Torchlight Property Solutions Limited | Real estate | 2021 |
| Torenia Limited | Real estate | 2019 |
| Torpane Ltd | Real estate | 2026 |
| Torpedo Films Ltd | Information & communication | 2026 |
| Torphyx Limited | Wholesale & retail | 2025 |
| Torq Commodities (UK) Ltd | Wholesale & retail | 2019 |