| Travelope Ltd | Administrative & support | 2025 |
| TRB Management Ltd | Construction | 2024 |
| Treasure Care Service Ltd | Health & social care | 2024 |
| Treats Unlimited Ltd | Arts & recreation | 2021 |
| Trend DRY Cleaners Ltd | Other services | 2015 |
| Trinity Health Care Services Ltd | Health & social care | 2022 |
| Trio Two Limited | Transport & logistics | 2010 |
| TRIP2GO Ltd | Administrative & support | 2024 |
| Triple a Management Consultants Ltd | Professional & scientific | 2010 |
| Triple J & R Limited | Health & social care | 2013 |
| Triple Joy Limited | Health & social care | 2019 |
| Triplesquare Limited | Health & social care | 2021 |
| Triplet Homeware Ltd | Wholesale & retail | 2025 |
| Tripplef Ltd | Health & social care | 2023 |
| Trivelles Blackpool Ltd | Real estate | 2018 |
| Trivelles Goldcrest Ltd | Real estate | 2018 |
| Trivelles Offices Ltd | Real estate | 2016 |
| Trivelles Preston Ltd | Real estate | 2017 |
| Trivelles River House Ltd | Hospitality | 2012 |
| Trivelles Trafford Ltd | Real estate | 2017 |
| TRL Line Ltd | Wholesale & retail | 2020 |
| Trove Group Ltd | Real estate | 2024 |
| True Homekare UK Limited | Health & social care | 2026 |
| Trunchi Limited | Transport & logistics | 2013 |
| TS Accountancy and Tax Ltd | Professional & scientific | 2026 |
| TS Asset Management Limited | Financial services | 2012 |
| TS Ventures Limited | Real estate | 2016 |
| TS3 Capital Limited | Real estate | 2023 |
| TSG Accountants Ltd | Professional & scientific | 2018 |
| TSQ Limited | Real estate | 2016 |
| TT Management Services Ltd | Administrative & support | 2024 |
| Tucker's Retail Limited | Wholesale & retail | 2025 |
| Tunedel Ltd | Wholesale & retail | 2020 |
| Tutorfy Ltd | Education | 2019 |
| TVA International Ltd | Information & communication | 2021 |
| Twincaterer Limited | Hospitality | 2023 |
| Tyre House 1 Ltd | Water & waste | 2022 |
| TYS Holdings Ltd | Financial services | 2023 |
| Tyzen Enterprise Ltd | Wholesale & retail | 2026 |
| TZW Limited | Administrative & support | 2017 |
| Uaaaa Limited | Real estate | 2025 |
| Uclaims Limited | Other services | 2004 |
| Ugperformance Limited | Information & communication | 2021 |
| UK Blessed Multitrader Consultant Limited | Real estate | 2019 |
| UK Building & Construction Ltd | Construction | 2020 |
| UK Car Hire Ltd | Administrative & support | 2025 |
| UK Container Sales Ltd | Other services | 2019 |
| UK Direct Commerce Ltd | Wholesale & retail | 2022 |
| UK Energy Surveys Ltd | Real estate | 2007 |
| UK Entertainment Group Ltd | Other services | 2022 |
| UK Fixed Ltd | Construction | 2025 |
| UK Motors Point Ltd | Wholesale & retail | 2020 |
| Uklink Green Climate Ltd | Construction | 2021 |
| Ukmathsrevision Ltd | Administrative & support | 2026 |
| Ukrainian Timber Ltd | Wholesale & retail | 2025 |
| Ultimate Events and Promotions Ltd | Arts & recreation | 2025 |
| Ultimet Alloys Limited | Wholesale & retail | 1997 |
| Ultra Beauty & Hair Ltd | Other services | 2021 |
| Ulue Limited | Real estate | 2022 |
| Umair Properties Ltd | Real estate | 2022 |
| Ummah Cars London Limited | Wholesale & retail | 2023 |
| Ummah Construction Limited | Construction | 2023 |
| Ummah Group Ltd | Financial services | 2023 |
| Ummah Property Limited | Real estate | 2023 |
| UNG Consultant Limited | Information & communication | 2023 |
| Unicorn Accounting Solutions Ltd | Professional & scientific | 2026 |
| Unified Properties Limited | Information & communication | 2021 |
| UNIGO2 Limited | Education | 2026 |
| Unipro Services Limited | Education | 2024 |
| Uniq Sports Management Limited | Professional & scientific | 2023 |
| Unique Engineering Services (UK) Ltd | Manufacturing | 2012 |
| Unique Healthcare Professionals Ltd | Health & social care | 2024 |
| Unique Support Early Years Limited | Health & social care | 2024 |
| Unique Thai Massage Ltd | Other services | 2025 |
| Uniquesoft Ltd | Information & communication | 2014 |
| Uniquesthetic Ltd | Other services | 2019 |
| Uniselect U.K. Ltd | Education | 2024 |
| Unison Raid Ltd | Wholesale & retail | 2025 |
| Universal Asset Sciences Ltd. | Administrative & support | 2017 |
| Universal Technical Ltd | Professional & scientific | 2023 |
| Uniways Global Limited | Administrative & support | 2022 |
| Unleash the Rockstar Limited | Education | 2025 |
| Unrushed Limited | Wholesale & retail | 2026 |
| Uperio UK Limited | Administrative & support | 2005 |
| Upminster Cars Ltd | Transport & logistics | 2021 |
| Uppamost Home Limited | Households | 2025 |
| Upus Ltd | Construction | 2024 |
| Upwardplus Properties Limited | Real estate | 2025 |
| Urban Londonn Ltd | Administrative & support | 2023 |
| Urban Monarch Ltd | Wholesale & retail | 2026 |
| Uthaya Traders Ltd | Wholesale & retail | 2019 |
| UTI Engineering Ltd | Professional & scientific | 2025 |
| Uzuniso Ltd | Hospitality | 2024 |
| V & C Property Developments Ltd | Real estate | 2019 |
| V & R Construction (LON) Ltd | Construction | 2023 |
| V Jitcu Ltd | Construction | 2023 |
| V&S Dryliners Ltd | Construction | 2025 |
| V&V Construction Ltd | Construction | 2021 |
| V.K Moss Properties Ltd | Real estate | 2025 |
| V2130 Labs IP Ltd | Professional & scientific | 2018 |