| Txtnation Holdings Limited | Information & communication | 2011 |
| Tyre Plus Ltd | Wholesale & retail | 2026 |
| Tyre Port Ltd | Wholesale & retail | 2024 |
| Tyresmiths (Plymouth) Ltd | Other services | 2016 |
| Tyrnanoge Technologies Ltd | Information & communication | 2022 |
| Tyrones Agricultural and Marine Engineers Limited | Wholesale & retail | 2011 |
| Tyson House Ltd | Real estate | 2025 |
| U Drive Cover Limited | Financial services | 2013 |
| U Mareczka Ltd | Hospitality | 2023 |
| U&I Leisure Ltd | Administrative & support | 2017 |
| U&I Security Services Ltd | Administrative & support | 2018 |
| Ubini Enterprise Ltd | Education | 2023 |
| Ubiquitous Media Ltd | Other services | 2024 |
| UBL (SW) Ltd | Households | 2016 |
| UBN Foods Ltd | Hospitality | 2026 |
| UC3 Facilities Ltd | Administrative & support | 2026 |
| UFH Direct Ltd | Construction | 2017 |
| UK Affiliate Management Ltd | Administrative & support | 2006 |
| UK Blinds (Plymouth) Ltd | Wholesale & retail | 2011 |
| UK Cream Chargers Limited | Financial services | 2012 |
| UK Custom Workwear Ltd | Wholesale & retail | 2026 |
| UK Deed Polls Ltd | Other services | 2025 |
| UK Fleet Ltd | Other services | 2018 |
| UK Hammer Ltd | Other services | 2025 |
| UK Mental Fitness CIC | Health & social care | 2026 |
| UK Pack.Net Ltd | Manufacturing | 2018 |
| UK Unique Food Ltd | Hospitality | 2024 |
| Ukoffer Ltd | Wholesale & retail | 2019 |
| Ulti Property Ltd | Construction | 2021 |
| Ultimate Driveways South West Limited | Construction | 2024 |
| Ultimate Solutions Hub Ltd | Education | 2024 |
| Ultra General Ltd | Transport & logistics | 2020 |
| Ultra Green Generators Ltd | Manufacturing | 2025 |
| Ultracardiac Ltd | Health & social care | 2014 |
| Umami Food and Farming Ltd | Agriculture & fishing | 2021 |
| Umat Limited | Hospitality | 2006 |
| Umbrella Power Limited | Wholesale & retail | 2022 |
| Umbrelladev Limited | Information & communication | 2025 |
| Underground Entertainment Ltd | Hospitality | 2017 |
| Underhill Building Services Limited | Construction | 2001 |
| Underhill Engineering (UK) Limited | Manufacturing | 2022 |
| Underhill Engineering Limited | Manufacturing | 1998 |
| Underhill Group Limited | Real estate | 2001 |
| Underhill Properties Ltd | Construction | 2017 |
| Unearth PR Limited | Professional & scientific | 2022 |
| UNI Burger MAN Ltd | Hospitality | 2019 |
| Uni-Lec Contractors Limited | Manufacturing | 2012 |
| Unified Technical Solutions Ltd | Information & communication | 2014 |
| Unify South West Ltd | Construction | 2020 |
| Unify Trading Ltd | Wholesale & retail | 2024 |
| Union Glass Balustrades & Balconies Ltd | Manufacturing | 2024 |
| Union Glass Centres Limited | Manufacturing | 1991 |
| Union House Grill Ltd | Hospitality | 2024 |
| Union Street Convenient Mini Market Limited | Wholesale & retail | 2024 |
| Unique H&S Consultants Ltd | Professional & scientific | 2018 |
| Unique Water Solutions Ltd | Construction | 2013 |
| Uniquity Marketing Limited | Professional & scientific | 2016 |
| Unis Logistics Ltd | Transport & logistics | 2019 |
| Unit Marine LLP | | 2022 |
| Unitbuild (SW) LLP | | 2012 |
| Unitbuild Limited | Construction | 2012 |
| United Inspection Services Limited | Manufacturing | 2013 |
| Unitsmart Property Management Limited | Households | 1988 |
| Unity Build & Repair Ltd | Construction | 2018 |
| Unity Gymnastics Academy CIC | Arts & recreation | 2020 |
| Unity Leadership Limited | Education | 2023 |
| Unity Through Sport CIC | Administrative & support | 2018 |
| Universal Care & Support Limited | Health & social care | 2019 |
| Universal Fire and Security Limited | Administrative & support | 2007 |
| Universal Marine Services Limited | Transport & logistics | 2012 |
| Universal Maritime Limited | Transport & logistics | 2004 |
| Universal Motorsport Limited | Arts & recreation | 2012 |
| Universe Investment Group ( Construction ) Limited | Construction | 2024 |
| Universe Investment Group ( Holdings ) Limited | Construction | 2023 |
| Universe Investment Group (Market Street) Limited | Construction | 2026 |
| Universe Investment Group Limited | Construction | 2017 |
| University Commercial Services Plymouth Limited | Administrative & support | 2007 |
| University of Plymouth Enterprise Limited | Administrative & support | 1999 |
| University of Plymouth Services Limited | Administrative & support | 2020 |
| University of ST Mark & ST John | Education | 2011 |
| Unlocking Abilities Together Ltd | Professional & scientific | 2024 |
| Unrivalled Education Limited | Education | 2025 |
| Unseen Press Collective C.I.C. | Information & communication | 2025 |
| Untamed Bladez Ltd | Other services | 2025 |
| UP Country Properties Ltd | Real estate | 2016 |
| Upfli Ltd | Professional & scientific | 2019 |
| Uplifto Ltd | Manufacturing | 2014 |
| Upshot Design Limited | Professional & scientific | 2022 |
| Upstate Engineering Ltd | Professional & scientific | 2026 |
| Upsu Trading Limited | Education | 2015 |
| Uptime Resourcing Ltd | Administrative & support | 2026 |
| Upvc Recycling South West Ltd | Water & waste | 2021 |
| Upward Loft Solutions Ltd | Manufacturing | 2023 |
| Urban Decorium Ltd | Manufacturing | 2025 |
| Urban FOX Project Limited | Other services | 2025 |
| Urban Projects SW Ltd | Construction | 2024 |
| Urbanmate Ltd | Administrative & support | 2025 |
| Urbanosa Ltd | Other services | 2019 |
| Urbanreaper Clothing Company Limited | Wholesale & retail | 2019 |
| Urbanunit Residents Management Limited | Households | 1988 |