| UK Vehicle Dismantlers Limited | Southend-On-Sea | 2015 |
| UK Vehicle Recycling Ltd | Brentwood | 2016 |
| UK Veritas Ltd | Glasgow | 2020 |
| UK Waste Away Ltd | Sidcup | 2025 |
| UK Waste Busters Ltd | Bournemouth | 2022 |
| UK Waste Clearance Ltd | London | 2026 |
| UK Waste Consultancy Ltd | London | 2009 |
| UK Waste Direct 2000 Limited | Basildon | 2023 |
| UK Waste Holdings Ltd | Maidstone | 2025 |
| UK Waste Managment Ltd | Hartlepool | 2025 |
| UK Waste Recycling Ltd | Milton Keynes | 2018 |
| UK Waste Solutions Limited | Telford | 2003 |
| UK Waste Tankers Ltd | London | 2025 |
| UK Water Co (North West) Limited | Manchester | 2019 |
| UK Xuechuangbang Environmental Technology Co., Ltd. | Cardiff | 2025 |
| Ukfprs Ltd | Lincoln | 2020 |
| Ukhb Support Services Limited | Doncaster | 2025 |
| Ukltd Limited | Liverpool | 2013 |
| Ukrs Total Waste Management Ltd | Stockport | 2012 |
| Ukwnw Limited | Liverpool | 2020 |
| Uloo Ltd | Reading | 2022 |
| Ultimate Drainage Ltd | Wolverhampton | 2021 |
| Ultimate Operations Limited | Codsall | 1992 |
| Ultimate Skips Ltd | Llanelli | 2018 |
| Ultimate Uplifts Ltd | Lanark | 2020 |
| Ultimate Waste Solutions Limited | London | 2018 |
| Ultra Drainclear Limited | Bromsgrove | 2014 |
| Ultra Envirotech (UK) Ltd | Ruislip, | 2025 |
| Ultra Recycle Energy Ltd | Manchester | 2025 |
| Ultra-Clean Jetting Services Ltd | Wednesbury | 2021 |
| Ultragy Limited | Knutsford | 2023 |
| Ultrarecycle Ltd | Bedford | 1992 |
| Ultrasonic Tubular Process Solutions Ltd | Birkenhead | 2024 |
| Ultrasound Scan London Ltd | London | 2022 |
| Ultromex Innovations Limited | Bromborough | 2018 |
| Ulverston Precision Machining Limited | Cumbria | 1987 |
| Unbloc Drain Services Limited | Frimley | 2014 |
| Unbloc Drainage Engineers Limited | Surrey | 1979 |
| Unblock Cumbria Limited | Gillingham | 1999 |
| Unblock Drainage Ltd | Ilford | 2025 |
| UNBLOCKS365 Services Limited | London | 2023 |
| Unboxed Ltd | Hyde | 2024 |
| Under Grid Ltd | Sutton Bridge | 2026 |
| Under Pressure Exterior Liverpool Ltd | Liverpool | 2025 |
| Underground Service Engineering Ltd | Newport | 2021 |
| Underground Vision UK Limited | Prestatyn | 2021 |
| Underground Water Ltd | Slough | 2018 |
| Uni-Skip & Container Services Limited | | 1978 |
| Unico Recycling Ltd | Birmingham | 2020 |
| Unified Biomass Limited | Preston | 2017 |
| Unified Waste Management Limited | Poulton-Le-Fylde | 2021 |
| Unimet Enterprises Limited | Rye | 2016 |
| Unimetals Recycling (UK) Limited | Birmingham | 1996 |
| Union Aggregates & Grab Hire Limited | Beverley | 2020 |
| Union Scrap Metals Limited | Potters Bar | 2017 |
| Unipex Tyre Recycling Ltd | Cardiff | 2002 |
| Unique Car Hire and Recovery Ltd | Cardiff | 2024 |
| Unique Drains Ltd | Wimborne | 2024 |
| Unique Fire Door Services Limited | Poole | 2024 |
| Unique Premise Ltd | London | 2013 |
| Unique Store Limited | Slough | 2025 |
| Unique Supa Shift Ltd | Liverpool | 2017 |
| Uniskip Environmental Services Limited | Brough | 2002 |
| Unit 2 Management Limited | York | 2004 |
| United Biofuel Ltd | London | 2023 |
| United Brokers (UK) Limited | Edinburgh | 2019 |
| United Car Breakers Ltd | Suffolk | 2018 |
| United Clinical Waste Services Limited | Birmingham | 2011 |
| United Commercial Trading(Uk) Limited | Warrington | 2007 |
| United Drains Ltd | Ongar | 2017 |
| United Energy Waste Management Ltd | Bangor | 2021 |
| United Junk Ltd | Stockport | 2011 |
| United Junk Skip Hire Limited | Stockport | 2013 |
| United Recycled Aggregates Limited | Abergavenny | 2009 |
| United Utilities Bioresources Limited | Warrington | 2016 |
| United Utilities International Limited | Lingley Green Avenue, Great | 1989 |
| United Utilities Water Limited | Lingley Green Avenue Great | 1989 |
| United Waste OIL Limited | London | 2013 |
| Unity of Humanity Ltd | London | 2023 |
| Unity Recycling Ltd | Nottingham | 2026 |
| Universal Bedding and Upholstery (1998) Limited | Sunderland | 1998 |
| Universal Car Services Limited | Loughton | 1991 |
| Universal Collect | London | 2018 |
| Universal Flooring Limited | London | 1993 |
| Universal FREQUENCY51 CIC | Alexandria | 2025 |
| Universal Metals (Hastings) Ltd | Rye | 2018 |
| Universal Metals Limited | Rye | 2002 |
| Universal N&D Ltd | London | 2021 |
| Universal Recycling Limited | Hessle | 2010 |
| Universal Tanker Solutions Limited | St Helens | 2003 |
| Universal Vitrum Limited | Nottingham | 2017 |
| Universal Waste Limited | Loughton | 2011 |
| Universal Waste Management Limited | Stevenage | 2019 |
| Universal Waste Recycling Limited | Newport | 2012 |
| Uniwaste Ltd | Rotherham | 2023 |
| Unplugged Recycling | Boston | 2002 |
| Untapped-Inc Limited | Oxted | 2017 |
| Unyte Waste Limited | Market Harborough | 2011 |
| UP and Running Drainage Limited | Sherborne | 2026 |
| UPC Majestic Services Limited | Nottingham | 2015 |