| Twelve Trees Care Limited | Professional & scientific | 2018 |
| Twelve Trees Home Care Limited | Health & social care | 2014 |
| Twelve Trees Limited | Health & social care | 2008 |
| Twelvetree Carpets Limited | Wholesale & retail | 2022 |
| Twenty One Developments Limited | Real estate | 2020 |
| Twenty Two Keys Ltd | Other services | 2025 |
| TWENTY3CONSULTING Ltd | Professional & scientific | 2013 |
| Twentywell Business Services Ltd | Professional & scientific | 2025 |
| Twentywell Developments Limited | Construction | 2013 |
| Twentywell Management Limited | Households | 1990 |
| Twentywell Rentals Limited | Real estate | 2025 |
| Twentywell River View Limited | Households | 2025 |
| Twilight Leisure Limited | Hospitality | 2013 |
| Twin Atlantic Limited | Administrative & support | 2024 |
| Twin Bank Limited | Administrative & support | 2021 |
| Twin Cafe Limited | Wholesale & retail | 2014 |
| Twinality Limited | Information & communication | 2026 |
| Twine London Limited | Wholesale & retail | 2025 |
| Twinflex Limited | Real estate | 1997 |
| Twinkl (Global Holdings) Ltd | Information & communication | 2016 |
| Twinkl Hive Services Ltd | Administrative & support | 2019 |
| Twinkl Ltd | Education | 2010 |
| Twinkle Ltd | Financial services | 2020 |
| Twinkle Studio Limited | Transport & logistics | 2020 |
| Twinkle Toes Shoes Limited | Wholesale & retail | 2006 |
| Twinkli Ltd | Manufacturing | 2025 |
| Twinpay Group Limited | Administrative & support | 2022 |
| Twinpay Ltd | Administrative & support | 2022 |
| Twins of Evil Limited | Administrative & support | 2001 |
| Twins Stars Ltd | Wholesale & retail | 2023 |
| Twixle Solutions Limited | Information & communication | 2025 |
| TWL Financial Limited | Professional & scientific | 2019 |
| TWL Music Limited | Information & communication | 2021 |
| TWM Luxury Ltd | Manufacturing | 2019 |
| Twnty Four Music Ltd | Professional & scientific | 2023 |
| Two Acre Holdings Ltd | Financial services | 2026 |
| Two Brothers Deli and Catering Ltd | Hospitality | 2025 |
| Two Eleven Management Company Limited | Households | 2005 |
| Two Gunned Saint Films Limited | Information & communication | 2012 |
| Two Knots Ltd | Wholesale & retail | 2023 |
| Two Mabels Ltd | Real estate | 2023 |
| Two Thirds Beer Co. Ltd | Wholesale & retail | 2021 |
| Two Thirds Different Ltd | Professional & scientific | 2020 |
| Two Wests & Elliott Limited | Wholesale & retail | 2007 |
| Two-Line Tortoise Ltd | Manufacturing | 2024 |
| Twoecom Ltd | Wholesale & retail | 2025 |
| Twothreed Consultancy Limited | Professional & scientific | 2019 |
| TWR Notarial Services Limited | Professional & scientific | 2019 |
| TWS Alloys Limited | Wholesale & retail | 2024 |
| TWS Investments Ltd | Real estate | 2021 |
| Txokos Ltd | Hospitality | 2023 |
| TY Eurvil Management Limited | Households | 2022 |
| TYA Private Ltd | Hospitality | 2026 |
| Tyack Consulting Limited | Information & communication | 2015 |
| Tyas Shaw & Co Limited | Professional & scientific | 2018 |
| Tyburn Lane Debt Management Limited | Construction | 2017 |
| Tyke Films Ltd | Information & communication | 2014 |
| Tyler Rail Limited | Manufacturing | 2018 |
| Tyma Neuro Consultants Ltd | Health & social care | 2015 |
| Tymah Properties Limited | Real estate | 2020 |
| Tyne Grange Health Care Limited | Health & social care | 2019 |
| Tyneside Automotive Ltd | Wholesale & retail | 2015 |
| Type Media Ltd | Wholesale & retail | 2025 |
| TYR Strength & Conditioning Ltd | Extraterritorial | 2025 |
| Tyrah's Touch Ltd | Other services | 2020 |
| Tyree Fabrications Limited | Manufacturing | 1981 |
| Tyremarks S35 Limited | Wholesale & retail | 2015 |
| Tytan Solutions Limited | Professional & scientific | 2016 |
| Tyto Solutions Ltd | Professional & scientific | 2023 |
| Tyxan Ltd | Information & communication | 2014 |
| Tyzack Limited | Professional & scientific | 1937 |
| Tyzack Machine Knives Limited | Manufacturing | 2001 |
| TZ Enterprises Ltd | Arts & recreation | 2015 |
| Tzai Ltd | Information & communication | 2025 |
| Tzeart Ltd | Manufacturing | 2023 |
| TZI Services Ltd | Health & social care | 2023 |
| U & T Union Ltd | Hospitality | 2019 |
| U Entertainment Ltd | Hospitality | 2011 |
| U H Ltd | Health & social care | 2003 |
| U Legend Innovation Service Limited | Administrative & support | 2024 |
| U Plus Mart Limited | Wholesale & retail | 2020 |
| U Travls Ltd | Transport & logistics | 2025 |
| U-Telecom Ltd | Information & communication | 2017 |
| U-Za Parts Ltd | Wholesale & retail | 2002 |
| U.G. Accountancy Ltd | Professional & scientific | 2024 |
| U.J‘Fly High’ Ltd | Wholesale & retail | 2025 |
| U.K. Medical Limited | Financial services | 1979 |
| UBH International Limited | Manufacturing | 1999 |
| Ubiquitous Particle Ltd | Information & communication | 2021 |
| UCA Engineering Limited | Professional & scientific | 2021 |
| UCC Worldwide Ltd | Agriculture & fishing | 2020 |
| UCH Medicals Limited | Health & social care | 2014 |
| Udaya Agro Farm Limited | Wholesale & retail | 2025 |
| Uddins FBA Limited | Wholesale & retail | 2023 |
| UDR Beeley Wood Limited | Real estate | 2007 |
| UE Holdings Ltd | Real estate | 2019 |
| UFN London Limited | Wholesale & retail | 2023 |
| UG Services Limited | Construction | 2017 |
| Ugrad Online Limited | Extraterritorial | 2014 |
| UHC Traders Ltd | Wholesale & retail | 2024 |