| Quantum Hive Solutions Ltd | Information & communication | 2026 |
| Quantum Links AI Limited | Information & communication | 2025 |
| Quantum Mortgages Limited | Financial services | 2021 |
| Quantum Park Homes Ltd | Other services | 2019 |
| Quantum Shift Global Ltd | Professional & scientific | 2014 |
| Quantum Ventures Management Ltd | Extraterritorial | 2024 |
| Quantum Wealth TA Moniq Ltd | Financial services | 2026 |
| Quarry Green Close Management Company Limited | Households | 2000 |
| Quartal Ltd | Transport & logistics | 2024 |
| Quarter Past Three Limited | Professional & scientific | 2026 |
| Quarterhorsecoffee Limited | Hospitality | 2012 |
| Quarto Consulting Limited | Professional & scientific | 1996 |
| Quarto IT Consulting Ltd | Information & communication | 2022 |
| Quartus Property Limited | Real estate | 2024 |
| Quartz.Xyz Limited | Real estate | 2024 |
| Quasariq Ltd | Information & communication | 2025 |
| Quasenso Ltd | Information & communication | 2026 |
| Quatro Climate Ltd | Professional & scientific | 2025 |
| Quatro P Holdings Limited | Financial services | 2024 |
| Quatro Park Management Limited | Real estate | 2005 |
| Quattro Property Holdings Ltd | Real estate | 2020 |
| Quaystone Group Ltd | Financial services | 2024 |
| Quaystone Investments Limited | Financial services | 2016 |
| Qube Logistics Limited | Administrative & support | 2011 |
| Qube OOH Limited | Professional & scientific | 2024 |
| Qubistiq Limited | Information & communication | 2024 |
| Qudos Rail Engineering Ltd | Manufacturing | 2015 |
| Queen of Sabba Ltd | Manufacturing | 2023 |
| Queens Park Mews Management (NO 1) Limited | Households | 1995 |
| Queens Park Mews Management (NO 2) Limited | Households | 1996 |
| Queens Park Mews Management (NO 3) Limited | Households | 1996 |
| Queensbury Construction Group Limited | Construction | 2020 |
| Queensbury Design Services Limited | Professional & scientific | 2020 |
| Queensbury Projects Limited | Extraterritorial | 2015 |
| Queensway Healthcare Ltd | Administrative & support | 2017 |
| Queja Ltd | Professional & scientific | 2019 |
| Quencies Limited | Professional & scientific | 2019 |
| Quest Accounting Services Limited | Professional & scientific | 2003 |
| Questex (U.K.) Limited | Administrative & support | 2001 |
| Quetech Limited | Manufacturing | 2020 |
| Queue Technologies Ltd | Information & communication | 2025 |
| Quick Cleanr Ltd | Administrative & support | 2026 |
| Quick Parcel Delivery Ltd | Transport & logistics | 2021 |
| Quick Pass With TM Ltd | Education | 2023 |
| Quickchannel Limited | Information & communication | 2020 |
| Quicklink Construction Limited | Construction | 2025 |
| Quicklinq Consult Ltd | Professional & scientific | 2017 |
| Quickpower Ltd | Other services | 2023 |
| Quiet Time Therapy CIC | Public administration | 2024 |
| Quiet Time Therapy Co Ltd | Public administration | 2025 |
| QUINONE7 Ltd | Professional & scientific | 2015 |
| Quintessential Inns Limited | Hospitality | 1993 |
| Quintessentially British Limited | Wholesale & retail | 2017 |
| Quintige Consulting Group Limited | Professional & scientific | 1999 |
| Quintiles IMS Holdings Limited | Extraterritorial | 2016 |
| Quintiles-Ims Health Limited | Extraterritorial | 2016 |
| Quintiles-Ims Limited | Extraterritorial | 2016 |
| Quintilesims Japan Limited | Extraterritorial | 2016 |
| Quintilesimshealth Japan Limited | Extraterritorial | 2016 |
| Quip Digital MK Limited | Professional & scientific | 2026 |
| Quirky Memories Ltd | Manufacturing | 2024 |
| Quoins Ventures Limited | Administrative & support | 2026 |
| Quomodo Consulting Limited | Financial services | 2013 |
| Quran Instructors Online Ltd | Education | 2025 |
| QUY Jewellers Limited | Wholesale & retail | 2019 |
| Qwik 'N' Qlean Solutions Ltd | Administrative & support | 2015 |
| R & a Farms Investments Limited | Financial services | 2022 |
| R & a Farms Property Investments Limited | Financial services | 2023 |
| R & a Fencing Supplies Limited | Construction | 2016 |
| R & B Scott Limited | Real estate | 2014 |
| R & C Property Acquisition Ltd | Real estate | 2021 |
| R & C Property Management Limited | Real estate | 2017 |
| R & M Properties (2012) Limited | Real estate | 2012 |
| R & P B Limited | Administrative & support | 2005 |
| R & R Properties (MK) Ltd | Real estate | 2022 |
| R Abdullah & Co Ltd | Hospitality | 2025 |
| R C Heliguru Limited | Wholesale & retail | 2012 |
| R Care Consultancy Ltd | Professional & scientific | 2025 |
| R Chandler Ltd | Information & communication | 2010 |
| R Duggan Investments Limited | Financial services | 2021 |
| R Duggan Limited | Administrative & support | 2016 |
| R Hawkins Electrical Ltd | Construction | 2021 |
| R J a Keynes Ltd | Hospitality | 2013 |
| R J Brown Scaffolding Limited | Construction | 2007 |
| R J Clarke Painting & Decorating Contractor Ltd | Construction | 2006 |
| R L P Developments Ltd | Wholesale & retail | 2016 |
| R M Carrington & SON Ltd | Construction | 2002 |
| R Mandava Ltd | Information & communication | 2011 |
| R Murphy Holdings Ltd | Financial services | 2020 |
| R S R Interiors Limited | Construction | 2010 |
| R S Response Ltd | Construction | 1997 |
| R Spiers Ltd | Information & communication | 2014 |
| R Warwick Limited | Manufacturing | 2024 |
| R&A Advantage Logistics Ltd | Administrative & support | 2022 |
| R&A Retail Hub Co Ltd | Financial services | 2023 |
| R&B Associated Company Ltd | Real estate | 2016 |
| R&B Distribution Ltd | Wholesale & retail | 2025 |
| R&B Marine Holdings Limited | Arts & recreation | 2009 |
| R&B Newman Limited | Construction | 2017 |
| R&B Ringstead Ltd | Construction | 2017 |