| TWI Estates Limited | Real estate | 1996 |
| TWI Limited | Real estate | 1999 |
| TWI Technology Centre (Yorkshire) Limited | Professional & scientific | 2002 |
| Twigden and Moss Limited | Construction | 2008 |
| Twigg Scientific & Technical Ltd | Professional & scientific | 2012 |
| Twin Electrical Services Limited | Construction | 2017 |
| Twin Light Limited | Wholesale & retail | 2015 |
| Twin Wing Aviation Ltd | Transport & logistics | 2026 |
| Twins Import & Export Trading Co., Limited | Extraterritorial | 2014 |
| Twinvita Ltd | Information & communication | 2025 |
| Twinwoods JV Limited | Construction | 2023 |
| Twisted Tree Games Limited | Information & communication | 2012 |
| Twistpoint Retail Limited | Hospitality | 2025 |
| Two Chefs Cambridge Limited | Manufacturing | 2023 |
| Two Eight Property Group Limited | Construction | 2018 |
| Two Eight Property Refurbishment Ltd | Construction | 2022 |
| Two MAN Crew Ltd | Information & communication | 2017 |
| Two Thousand Five Hundred Limited | Education | 2021 |
| Two Trees Limited | Construction | 2025 |
| Two Two Two Ting Ltd. | Professional & scientific | 2018 |
| Twoflix Ltd | Information & communication | 2017 |
| Twoshome General Merchandise Co., Ltd | Extraterritorial | 2025 |
| Twoshome Houseware Co., Ltd | Wholesale & retail | 2025 |
| TWP (Trading) Company Limited | Administrative & support | 2002 |
| TWS Developments 2 Limited | Financial services | 2026 |
| TWS Developments Limited | Real estate | 2011 |
| TWT Dehydrates Ltd | Manufacturing | 2021 |
| Twth International Logistics (UK) Limited | Transport & logistics | 2023 |
| Twyft Consulting Ltd | Administrative & support | 2012 |
| Ty-Gard Europe Limited | Wholesale & retail | 1997 |
| Tyche Partners Ltd | Professional & scientific | 2019 |
| Tylicki Bloodstock Limited | Arts & recreation | 2013 |
| Tyndale House and Institute | Arts & recreation | 2015 |
| Tyndale Land Limited | Professional & scientific | 2025 |
| Type 2 Detectives Deluxe Ltd | Extraterritorial | 2014 |
| Type 3 Detectives Limited | Wholesale & retail | 2004 |
| Typhur Innovations Limited | Wholesale & retail | 2024 |
| Tyrell AI Ltd | Wholesale & retail | 2024 |
| TYV Group Ltd. | Information & communication | 2025 |
| TZM Ltd | Manufacturing | 2024 |
| U&N Linen’S Ltd | Administrative & support | 2025 |
| U&N Solution Ltd | Construction | 2025 |
| U&Z Logistics Ltd | Transport & logistics | 2021 |
| U-Blox Cambridge Ltd | Information & communication | 2009 |
| U-Blox Luton Limited | Professional & scientific | 2006 |
| U.G.A.Construction Limited | Construction | 2020 |
| U.Q.G. Limited | Manufacturing | 1973 |
| U3 Foundation | Financial services | 2025 |
| UA Homes Ltd | Construction | 2021 |
| Uadd Limited | Information & communication | 2019 |
| Ubeauty International Ltd | Extraterritorial | 2017 |
| Ubelu Legacy Property Limited | Administrative & support | 2026 |
| Uber Tuning UK Limited | Manufacturing | 2016 |
| Ubet Ltd | Arts & recreation | 2022 |
| Ubicorn Limited | Professional & scientific | 2018 |
| Ubisense Limited | Professional & scientific | 2002 |
| Ubuntopia Limited | Information & communication | 2016 |
| Ubuntu Heritage Ltd | Construction | 2021 |
| UC Cloud Computing PS Ltd. | Information & communication | 2021 |
| Udaye Ltd | Construction | 2025 |
| Udyan Ltd | Hospitality | 2023 |
| UE Oversea Education Limited | Administrative & support | 2017 |
| UE Textile Co., Ltd | Wholesale & retail | 2026 |
| Ufinco Limited | Wholesale & retail | 2026 |
| Ugly Official UK Ltd | Arts & recreation | 2023 |
| Uiosna Limited | Wholesale & retail | 2021 |
| UK 3B Bios Limited | Mining & quarrying | 2025 |
| UK Agro Solutions Ltd | Administrative & support | 2020 |
| UK Aibon Plant Health Co., Ltd | Mining & quarrying | 2026 |
| UK Aipai Personal Care Daily USE Limited | Wholesale & retail | 2024 |
| UK Altai Mobile Technology Limited | Information & communication | 2025 |
| UK Amais Specialty Crop Nutrition Co., Ltd | Mining & quarrying | 2024 |
| UK Ambili Crop Protection Co., Ltd | Mining & quarrying | 2025 |
| UK Angivbrxkpacc-Clothing (International) Limited | Manufacturing | 2025 |
| UK Aplikon Agricultural Development Co., Ltd. | Wholesale & retail | 2023 |
| UK Appmediaex Technology Ltd | Information & communication | 2025 |
| UK Aptamil Crop Nutrition International Limited | Extraterritorial | 2023 |
| UK APV. HS Manufacturing Limited | Professional & scientific | 2016 |
| UK Arctic Harvest Exports Ltd | Wholesale & retail | 2025 |
| UK Arts and Design Association | Information & communication | 2024 |
| UK Asynon Chemical Co., Ltd | Mining & quarrying | 2025 |
| UK Auto Grand Industrial Co., Ltd | Wholesale & retail | 2014 |
| UK Bailis Nutrition Co., Ltd | Mining & quarrying | 2025 |
| UK Bayes Chemical Ltd | Manufacturing | 2020 |
| UK Bayho International Crop Nutrition Co., Ltd | Wholesale & retail | 2022 |
| UK Beho Environment Technology Group Ltd | Manufacturing | 2020 |
| UK Beidilante Int'L Crop Ltd | Extraterritorial | 2019 |
| UK Bella Figura Limited | Manufacturing | 2024 |
| UK Bellamy International Chemical Limited | Wholesale & retail | 2024 |
| UK Bergamo Valve Co., Ltd | Manufacturing | 2025 |
| UK Bingli Group Co., Ltd | Wholesale & retail | 2025 |
| UK Bio-Legend Ltd. | Extraterritorial | 2013 |
| UK Bioom Limited | Mining & quarrying | 2021 |
| UK Birmingham Trading Technology Co., Ltd | Extraterritorial | 2023 |
| UK Bitan International Group Co., Ltd | Mining & quarrying | 2025 |
| UK Blatt Crop Nutrition Co., Ltd | Mining & quarrying | 2025 |
| UK Brand Supply Ltd | Wholesale & retail | 2026 |
| UK Building & Renovations Ltd | Construction | 2026 |
| UK BWA Chemical Limited | Other services | 2021 |
| UK Calvin Plant Health Ltd | Mining & quarrying | 2021 |