| Pyramidia Limited | Health & social care | 2026 |
| Q 5 IT Limited | Information & communication | 2017 |
| Q Dental Practices Limited | Health & social care | 2010 |
| Q F I Electrical Ltd | Construction | 2020 |
| Q J Dental Limited | Health & social care | 2025 |
| Q Nine Partners Limited | Professional & scientific | 2018 |
| Q Slice Ltd | Information & communication | 2021 |
| Q&S Plus Limited | Health & social care | 2015 |
| Q-Equip Limited | Professional & scientific | 2017 |
| Q2B Consulting Ltd | Administrative & support | 2019 |
| Q7 Freelance Quality Solutions Limited | Administrative & support | 2011 |
| QA Training Ltd | Education | 2023 |
| Qacp Solutions Ltd | Professional & scientific | 2022 |
| Qaiser and Sana Ltd | Administrative & support | 2025 |
| Qasos Limited | Professional & scientific | 2010 |
| Qasr Limited | Professional & scientific | 2009 |
| QB Security Services Ltd | Administrative & support | 2009 |
| Qbitqidi Ltd | Information & communication | 2019 |
| QE Validation Limited | Administrative & support | 2012 |
| QFF Limited | Administrative & support | 2002 |
| Qfinancial Limited | Financial services | 2003 |
| Qingdao Polychem ( U.K.) Limited | Wholesale & retail | 2007 |
| Qmac Limited | Professional & scientific | 2026 |
| QMS Compliance Limited | Administrative & support | 2010 |
| Qntm Ltd | Information & communication | 2019 |
| QPC Pharma Consultancy Ltd | Administrative & support | 2022 |
| Qprcassidy Ltd | Professional & scientific | 2019 |
| QS Assistant Ltd | Education | 2025 |
| QS Contracts Limited | Construction | 2018 |
| QSR Launch Limited | Administrative & support | 2024 |
| QSS MA Ltd | Professional & scientific | 2024 |
| Quadlogic Limited | Administrative & support | 2013 |
| Quadracollective Ltd | Wholesale & retail | 2026 |
| Quaker Warrington Limited | Hospitality | 2025 |
| Quali Limited | Extraterritorial | 2017 |
| Qualis Commercial Services Limited | Professional & scientific | 2018 |
| Quality Access Training Ltd | Education | 2017 |
| Quality Audit Services Limited | Administrative & support | 2018 |
| Quality Build Solutions Ltd | Construction | 2025 |
| Quality Connexions Limited | Administrative & support | 2015 |
| Quality Management Services Ltd | Administrative & support | 2022 |
| Quality Never Sleeps Limited | Administrative & support | 2012 |
| Quality Perfected Ltd | Administrative & support | 2023 |
| Quality Property Investments North West Ltd | Construction | 2025 |
| Qualopus GSE Ltd | Professional & scientific | 2019 |
| Quane Limited | Information & communication | 2019 |
| Quant and Sons Ltd | Manufacturing | 2015 |
| Quantal Timber Merchants Limited | Administrative & support | 2024 |
| Quantile Project Management Limited | Professional & scientific | 2019 |
| Quantitative & Mechanical Engineering Limited | Professional & scientific | 2025 |
| Quantity Surveyors UK Limited | Professional & scientific | 2019 |
| Quanttum Surveying Limited | Administrative & support | 2016 |
| Quantum Bridge Limited | Professional & scientific | 2014 |
| Quantum Ceramics Ltd | Construction | 2019 |
| Quantum Connections Limited | Professional & scientific | 1996 |
| Quantum Health Solutions Limited | Health & social care | 2019 |
| Quantum Property Portfolios Ltd | Real estate | 2012 |
| Quantum Renewables NW Ltd | Construction | 2022 |
| Quantum Star (MCR) Limited | Construction | 2025 |
| Quantum Strategic Solutions Limited | Manufacturing | 1993 |
| Quantum Technical Public Relations Limited | Professional & scientific | 1985 |
| Quantum Tiger Limited | Information & communication | 2011 |
| Quantval Consulting Limited | Professional & scientific | 2012 |
| Quantwisdom Labs Ltd | Information & communication | 2024 |
| Quasimodo's Cleaning Solutions. Ltd | Administrative & support | 2025 |
| Quatrec Holdings Limited | Financial services | 2011 |
| Quattro UK Logistics Ltd | Water & waste | 2020 |
| Quay Assetz Limited | Real estate | 2019 |
| Quay Primary Healthcare C.I.C. | Health & social care | 2014 |
| Quays Protect (UK) Limited | Professional & scientific | 2015 |
| Qubetix Limited | Other services | 2017 |
| Queendom Hair and Beauty Limited | Other services | 2021 |
| Queensbeck Law Ltd | Extraterritorial | 2016 |
| Queensbeck Ltd | Extraterritorial | 2016 |
| Quench Cafe Limited | Hospitality | 2015 |
| Quick Boil Limited | Construction | 2024 |
| Quick Core Services Ltd | Administrative & support | 2004 |
| Quick DSP Ltd | Transport & logistics | 2024 |
| Quick Shift North West Ltd | Transport & logistics | 2025 |
| Quickqual Limited | Administrative & support | 2017 |
| Quicksilver Engineering Limited | Administrative & support | 2007 |
| Quiddity Ventures Ltd | Professional & scientific | 2015 |
| Quiet Mind Care Ltd | Health & social care | 2026 |
| Quigly Limited | Administrative & support | 2006 |
| Quinn Design Consultancy Limited | Professional & scientific | 2016 |
| Quinn Project Services Limited | Administrative & support | 2007 |
| Quinnetic Solutions Limited | Administrative & support | 2025 |
| Quinns Composites Limited | Administrative & support | 2025 |
| Quintessential Bathrooms Ltd | Construction | 2024 |
| Quintessential Brands UK Group Limited | Financial services | 2011 |
| Quintessential Brands UK Holdings Limited | Financial services | 2011 |
| Quintessential Bullion Ltd | Wholesale & retail | 2025 |
| Quintessential Spirits UK Limited | Wholesale & retail | 2011 |
| Quiq Ltd | Information & communication | 2023 |
| Quixotic Services (UK) Limited | Professional & scientific | 2015 |
| Quodria Ltd | Professional & scientific | 2024 |
| Quoi Solutions Limited | Other services | 2018 |
| Quoile Services Limited | Administrative & support | 2007 |
| Quortex People Ltd. | Professional & scientific | 2005 |
| Quotex Ltd | Professional & scientific | 2026 |