| Purepath Products Limited | Wholesale & retail | 2025 |
| Purilux Cleanner Ltd | Administrative & support | 2026 |
| Purple Cat Consulting Ltd | Professional & scientific | 2025 |
| Purple Hibiscus Consulting Limited | Professional & scientific | 2012 |
| Purple Patch TV Limited | Information & communication | 2018 |
| Purrry Waves Ltd | Wholesale & retail | 2024 |
| Purv Consulting Limited | Information & communication | 2024 |
| Puspa Foods Limited | Hospitality | 2023 |
| Puteri Limited | Health & social care | 2021 |
| PV Construction Ltd | Construction | 2025 |
| PVK Systems Ltd | Information & communication | 2022 |
| PVW Associates Limited | Information & communication | 2015 |
| Pydatamcr Ltd | Information & communication | 2024 |
| Pyramid Consulting Inc UK Ltd | Administrative & support | 2006 |
| Pyramid Healthcare 1 Ltd | Wholesale & retail | 2017 |
| Pyramid Healthcare 2 Limited | Wholesale & retail | 2025 |
| Pyramid Supported Housing Solutions Limited | Health & social care | 2017 |
| Pyromaxx FX Ltd | Information & communication | 2025 |
| Pyrostop Limited | Construction | 2025 |
| Q Fatima Ltd | Education | 2008 |
| Q Hussain Consultants Limited | Wholesale & retail | 2015 |
| Q Properties London Limited | Real estate | 2016 |
| Q&A Associates Ltd | Information & communication | 2017 |
| QA Resource Limited | Information & communication | 2008 |
| Qainsphere Limited | Wholesale & retail | 2024 |
| Qais Investments Ltd | Real estate | 2022 |
| Qamca UK C.I.C. | Education | 2023 |
| QAS Ventures Ltd | Wholesale & retail | 2025 |
| Qasimi Construction Limited | Construction | 2022 |
| QB Logistics Ltd | Transport & logistics | 2024 |
| QCD Autocentres Ltd | Financial services | 2019 |
| Qcon Consultancy Limited | Professional & scientific | 2022 |
| Qgalaxi Consulting Limited | Information & communication | 2010 |
| QGM Traders Limited | Wholesale & retail | 2022 |
| QH Nails and Spa Ltd | Other services | 2022 |
| QI Consultants Ltd | Information & communication | 2019 |
| Qinwan Dates London Limited | Manufacturing | 2020 |
| Qiquan International Ltd | Education | 2015 |
| QJS Consulting Limited | Professional & scientific | 2012 |
| Qoli Construction Ltd | Construction | 2026 |
| QR Consult Ltd | Professional & scientific | 2026 |
| QT Gifts Ltd | Wholesale & retail | 1987 |
| Qtangle Ltd | Real estate | 2022 |
| Qu-T Design Limited | Information & communication | 2012 |
| Quad Assets Limited | Financial services | 2020 |
| Quadrant Estate Planning Ltd | Other services | 2019 |
| Quadrant Pension Services Ltd | Other services | 2014 |
| Qual Serve GAS and Heating Services Ltd | Construction | 2019 |
| Qualdoors Ltd | Construction | 2018 |
| Qualified Aesthetics Ltd | Other services | 2023 |
| Quality Kennels Ltd | Wholesale & retail | 2024 |
| Quality Lounge Suites Limited | Manufacturing | 2006 |
| Quality Qube Limited | Information & communication | 2018 |
| Quality Service Standards Limited | Professional & scientific | 1999 |
| Quality Veneer Ltd | Manufacturing | 2025 |
| Qualitylet UK Limited | Construction | 1996 |
| Qualytest Ltd. | Information & communication | 2022 |
| Quant Property Ltd | Real estate | 2025 |
| Quantavise Ltd | Information & communication | 2024 |
| Quantivus Ltd | Professional & scientific | 2025 |
| Quantock EPS Ltd | Education | 2024 |
| Quantum Detection Limited | Administrative & support | 2009 |
| Quantum Forensics Limited | Professional & scientific | 2024 |
| Quantum Global Consulting Ltd | Professional & scientific | 2017 |
| Quantum of Storage Ltd | Information & communication | 2014 |
| Quantum PM LLP | | 2021 |
| Quantum Windows Limited | Manufacturing | 2004 |
| Quarlena Cooling Ltd | Energy | 2025 |
| Quarry Garage (Branton) Limited | | 1986 |
| Quartz Global Ltd | Professional & scientific | 1995 |
| Quartz Investment Holdings Ltd | Financial services | 2022 |
| Quartz Real Estate Ltd | Real estate | 2022 |
| Quay Crew Limited | Administrative & support | 2013 |
| Quay Group International Limited | Administrative & support | 2026 |
| Qudrant Phones and Repair Ltd | Other services | 2023 |
| Queens Court (Watford) Residents Association Limited | Real estate | 1996 |
| Queens Court Management Company (Leyton) Limited | Real estate | 2001 |
| Queensland Investments (UK) Ltd | Real estate | 2008 |
| Quest Estate Agency Limited | Real estate | 2013 |
| Quest Management Operations Ltd | Households | 2023 |
| Quest Property Construction Limited | Construction | 2013 |
| Quia Ltd | Information & communication | 2020 |
| Quick Change Mobile Tyre Ltd | Wholesale & retail | 2023 |
| Quick Consultants Ltd | Professional & scientific | 2011 |
| Quick Diagnostics POC Limited | Professional & scientific | 2016 |
| Quick Medix Doctors Ltd | Administrative & support | 2018 |
| Quick Medix Ltd | Administrative & support | 2017 |
| Quick Moove Limited | Real estate | 2019 |
| Quick Movers Ltd | Transport & logistics | 2018 |
| Quick Vehicle Transport and Recovery (Qvtr) Ltd | Transport & logistics | 2026 |
| Quickclean Pro Ltd | Administrative & support | 2026 |
| Quickpaye Agency Limited | Administrative & support | 2010 |
| Quickstart Projects Limited | Information & communication | 2011 |
| Quigar Creative Limited | Other services | 2018 |
| Quilia Ltd. | Professional & scientific | 2014 |
| Quilla Consulting Limited | Professional & scientific | 2011 |
| Quilljest Supply Chain Consultants Ltd | Professional & scientific | 2016 |
| Quinas Cardiac Diagnostics Ltd | Health & social care | 2022 |
| Quinn Civils and Plant Limited | Construction | 2018 |
| Quintas Global Solutions Ltd | Professional & scientific | 2025 |