| Qreates Limited | Information & communication | 2021 |
| QRG Ltd | Wholesale & retail | 2024 |
| QS Bar Group Ltd | Hospitality | 2020 |
| QSC Holdings Limited | Real estate | 2002 |
| QSG Limited | Extraterritorial | 1986 |
| QSQ Art Limited | Wholesale & retail | 2025 |
| QSS Logistics Ltd | Transport & logistics | 2021 |
| QTC Limited | Wholesale & retail | 2003 |
| Quad Automotive Ltd | Wholesale & retail | 2024 |
| Quad Computer Services Ltd | Information & communication | 1999 |
| Quad Microtech Limited | Information & communication | 1990 |
| Quadd Ltd | Information & communication | 2014 |
| Quader Estates Limited | Real estate | 2016 |
| Quadnetics Employees' Trustees Limited | Administrative & support | 1987 |
| Quadnetics Group Employee Share Scheme Limited Partnership | | 2005 |
| Quadnetics Group Limited | Extraterritorial | 2001 |
| Quadnetics Limited | Extraterritorial | 1988 |
| Quadnetics SIP Trustees Limited | Extraterritorial | 2006 |
| Quadrant Properties Ltd. | Extraterritorial | 1983 |
| Quadrant Research & Development Limited | Extraterritorial | 1991 |
| Quadrant Security Group Limited | Extraterritorial | 1983 |
| Quadratray Limited | Information & communication | 2014 |
| Qualified Schools Limited | Administrative & support | 2017 |
| Qualified Teachers Limited | Administrative & support | 2017 |
| Qualimach (Quality Machinery) Limited | Extraterritorial | 2012 |
| Qualimach Limited | Wholesale & retail | 1980 |
| Qualitas Compliance Limited | Professional & scientific | 2012 |
| Quality Air Extraction Limited | Construction | 2019 |
| Quality Air Solutions Ltd | Construction | 2026 |
| Quality Auto Solutions Limited | Wholesale & retail | 2023 |
| Quality Cars Holding Limited | Wholesale & retail | 2009 |
| Quality Cars Today.Co.Uk Limited | Wholesale & retail | 2015 |
| Quality Drinks Direct Limited | Extraterritorial | 2010 |
| Quality Furniture Stores Ltd | Wholesale & retail | 2022 |
| Quality ID Cards Limited | Administrative & support | 2010 |
| Quality Implant Services Limited | Health & social care | 2011 |
| Quality Lift Products Limited | Professional & scientific | 1983 |
| Quality Pizza Birley Ltd | Hospitality | 2025 |
| Quality Prestige Motors Limited | Wholesale & retail | 2024 |
| Quality Prime Hub Ltd | Wholesale & retail | 2025 |
| Quality Response Services Ltd | Other services | 2018 |
| Quality Tyres and MOT Ltd | Wholesale & retail | 2022 |
| Quansis Ltd | Professional & scientific | 2024 |
| Quantify Risk Management Limited | Professional & scientific | 2018 |
| Quantity Accounting Ltd | Professional & scientific | 2018 |
| Quantower West Ltd | Information & communication | 2022 |
| Quantum Air Conditioning Limited | Construction | 2023 |
| Quantum Deck Ltd | Wholesale & retail | 2025 |
| Quantum Earth Exchange Ltd | Extraterritorial | 2025 |
| Quantum Force Talent Ltd | Administrative & support | 2022 |
| Quantum Mass Limited | Wholesale & retail | 2014 |
| Quantum Mechanics Ltd | Professional & scientific | 2009 |
| Quantum Pixar AI Ltd | Information & communication | 2025 |
| Quantum Stone UK Ltd | Wholesale & retail | 2022 |
| Quantumquick Mart Ltd | Wholesale & retail | 2025 |
| Quantumstrat Ltd | Wholesale & retail | 2023 |
| Quantumy Ltd | Professional & scientific | 2024 |
| Quantura Limited | Administrative & support | 2018 |
| Quarmby Music Limited | Information & communication | 2014 |
| Quarry Motor Repairs Ltd | Wholesale & retail | 2017 |
| Quarry Motor Sales Ltd | Wholesale & retail | 2016 |
| Quarry Motor Spares Limited | Wholesale & retail | 2008 |
| Quarryfields Health Care Limited | Health & social care | 2010 |
| Quarterpenny Limited | Information & communication | 2006 |
| Quatermass Limited | Administrative & support | 2001 |
| Quatrevents Ltd | Professional & scientific | 2025 |
| Quatro P Ltd | Transport & logistics | 2019 |
| Quba Digital Limited | Professional & scientific | 2000 |
| Quba Ltd | Professional & scientific | 2023 |
| QUBE7 Ltd | Wholesale & retail | 2026 |
| QUE TEE Global Services Limited | Transport & logistics | 2025 |
| Queen Street Trustees Limited | Financial services | 2000 |
| Queen Victoria Road Lessees Limited | Households | 2019 |
| Queensberry Real Estate (UK) Ltd | Real estate | 2011 |
| Queensberry Real Estate Holdings Ltd | Financial services | 2017 |
| Queensberry Real Estate Investments LLP | | 2011 |
| Queensberry Real Estate LLP | | 2017 |
| Queenscourt Limited | Hospitality | 1995 |
| Queenswood Maintenance Limited | Construction | 2024 |
| Quenby Anaesthesia Ltd | Health & social care | 2022 |
| Quench Your Event Ltd | Hospitality | 2020 |
| Quesco Brasil Translations Ltd. | Professional & scientific | 2012 |
| Quest Business Solutions Limited | Information & communication | 1987 |
| Quick Commercial Ventures Limited | Construction | 2025 |
| Quick Deal Store Ltd | Wholesale & retail | 2026 |
| Quick Draft - Design and Engineering Services Limited | Professional & scientific | 2026 |
| Quick Hire Rentals Limited | Administrative & support | 2024 |
| Quick Imaging Centre Limited | Extraterritorial | 1965 |
| Quick March Removals Limited | Transport & logistics | 2017 |
| Quick Play Sport Ltd | Wholesale & retail | 2007 |
| Quick Response Cabs Limited | Transport & logistics | 2023 |
| Quick Ship Logistics Limited | Transport & logistics | 2019 |
| Quick Smile Limited | Extraterritorial | 2015 |
| Quickfire Holdings Limited | Real estate | 2004 |
| Quickfire Tableware Limited | Wholesale & retail | 2001 |
| Quickfit Car Chargers Ltd | Construction | 2025 |
| Quickmission Limited | Transport & logistics | 1999 |
| Quicktender Ltd | Wholesale & retail | 2022 |
| Quicktip Limited | Extraterritorial | 1990 |
| Quileutes Ltd | Real estate | 2025 |