| QGO Logistical Systems Ltd | Information & communication | 2019 |
| QH (UK) Realisations Limited | Real estate | 2012 |
| QID Solutions Limited | Construction | 2020 |
| Qivo Ltd | Wholesale & retail | 2025 |
| Qore Studio Ltd | Other services | 2014 |
| QP (East Anglia) Holdings Ltd | Financial services | 2021 |
| QP (East Anglia) Investments Ltd | Financial services | 2023 |
| QP (East Anglia) Properties Ltd | Real estate | 2017 |
| QP (Ghlsf) Investments Ltd | Financial services | 2023 |
| QP Timber Ltd | Wholesale & retail | 2006 |
| Qq&M Visa and Immigration Consultants Ltd | Professional & scientific | 2025 |
| QR Automation Limited | Wholesale & retail | 2025 |
| QRI Services Ltd | Transport & logistics | 2017 |
| Qris Services Ltd | Transport & logistics | 2021 |
| QSS Management Limited | Other services | 2017 |
| QSV Multi Service Group Ltd. | Manufacturing | 2019 |
| Quad Air Imaging Ltd | Extraterritorial | 2018 |
| Quad Bikes R US Ltd | Wholesale & retail | 2003 |
| Quadcorner Limited | Professional & scientific | 2010 |
| Quadrant Town Planning Ltd | Professional & scientific | 2009 |
| Quads R US Ltd | Extraterritorial | 2005 |
| Quality Air Conditioning & Refrigeration Ltd | Construction | 2017 |
| Quality Analysis Limited | Manufacturing | 1986 |
| Quality Care Provision Ltd | Administrative & support | 2013 |
| Quality Care Resourcing Limited | Health & social care | 2016 |
| Quality Caring Services Limited | Health & social care | 2020 |
| Quality Diagnostic Operating Systems (Qdos) | | 1996 |
| Quality Matters Support Limited | Professional & scientific | 2014 |
| Quality Metalwork Services Limited | Manufacturing | 1998 |
| Quality Render Ltd | Construction | 2020 |
| Quality Source Limited | Manufacturing | 2012 |
| Quality Staff Provider Ltd | Other services | 2016 |
| Qualogue Ltd | Professional & scientific | 2017 |
| Quantam Ledger Limited | Information & communication | 2026 |
| Quanticore Labs Ltd | Information & communication | 2025 |
| Quantile Alpha Ltd | Administrative & support | 2024 |
| Quantum Interior Solutions Ltd | Construction | 2019 |
| Quantum Tera Ltd | Information & communication | 2026 |
| Quantwise Ltd | Education | 2025 |
| Quarry Bay Investors Limited | Financial services | 2016 |
| Quartermaster Drinks Limited | Wholesale & retail | 2026 |
| Quartermaster Place Limited | Households | 2018 |
| Quartz Healthcare (UK) Limited | Health & social care | 2013 |
| Quartz Silica Products Limited | Manufacturing | 2015 |
| Quasarr Ltd | Wholesale & retail | 2025 |
| Quatech Solutions Ltd | Information & communication | 2023 |
| Quatra Group Holdings Limited | Financial services | 2021 |
| Quatra Holdings Limited | Financial services | 2026 |
| Quay West Residents Management Company Limited | Households | 2002 |
| Quayside (Colchester) NO.1 RTM Company Limited | Households | 2012 |
| Quayside (Colchester) NO.2 RTM Company Limited | Households | 2012 |
| Quayside (Colchester) NO.3 RTM Company Limited | Households | 2011 |
| Quayside (Colchester) NO.4 RTM Company Limited | Households | 2012 |
| Quayside (Colchester) NO.5 RTM Company Limited | Households | 2012 |
| Quayside Investments Limited | Construction | 2018 |
| Quayside Vietnam Limited | Hospitality | 2023 |
| Quaytech UK Unlimited | Wholesale & retail | 2018 |
| Qubic Tech Ltd | Professional & scientific | 2023 |
| QUE Automotive Limited | Wholesale & retail | 2017 |
| QUE Concept Ltd | Administrative & support | 2023 |
| Quebec Court (Dereham) Residents Management Company Limited | Households | 2014 |
| Queen BEE Coffee Limited | Hospitality | 2015 |
| Queen Mary's Court Freehold Limited | Households | 2011 |
| Queen Street Surgery Limited | Health & social care | 2006 |
| Queens Court (Hornchurch) Ltd | Real estate | 2006 |
| Queens Court East (1990) Limited | Households | 1990 |
| Queens Court Management Company (West Mersea) Limited | Households | 1997 |
| Queens House (Frinton) Limited | Households | 1993 |
| Queens Meadow (Heath Road Hockering) Management Company Limited | Households | 2017 |
| Queens Retreat (West Bergholt) Management Company Limited | Households | 2005 |
| Queensberry Property Investments Limited | Real estate | 2021 |
| Quercus Artus Ltd | Hospitality | 2021 |
| Quercus Ergonomics Limited | Manufacturing | 2011 |
| Quercus Properties (Essex) Ltd | Households | 2025 |
| Quest Advisory and Consultancy Services Limited | Professional & scientific | 2025 |
| Questco Advisors Ltd | Professional & scientific | 2024 |
| Questsolve Limited | Information & communication | 1992 |
| QUID2 Limited | Information & communication | 2014 |
| Quiessence Massage Ltd | Health & social care | 2014 |
| Quiet Commitment Ltd | Health & social care | 2026 |
| Quietland LLP | | 2023 |
| Quilley Properties Limited | Real estate | 2014 |
| Quintetto Management Company Ltd | Households | 2025 |
| Quintillion Group Limited | Professional & scientific | 2017 |
| Quintillion Team Technologies Ltd | Information & communication | 2021 |
| Quirk Design & Build Limited | Construction | 2006 |
| Quirky Dog Creative Limited | Information & communication | 2025 |
| Quite Nice Inns Ltd | Real estate | 2026 |
| Quoteai Ltd | Information & communication | 2025 |
| Quotemate Ltd | Information & communication | 2026 |
| Qurat & Rizvi Limited | Health & social care | 2017 |
| Qwerk Limited | Arts & recreation | 2007 |
| R & a Floors Limited | Construction | 2016 |
| R & B Plastering Limited | Construction | 1998 |
| R & C Distribution Limited | Wholesale & retail | 2004 |
| R & C Plant Services Limited | Manufacturing | 2003 |
| R & C Warehousing Ltd | Financial services | 2022 |
| R & D Cook Ltd | Construction | 2005 |
| R & H Accountants Limited | Professional & scientific | 2023 |
| R & K Consultancy Services Ltd | Professional & scientific | 2020 |