| Puttify Limited | Arts & recreation | 2023 |
| Puzdrowski Transport Ltd | Transport & logistics | 2026 |
| Puzzle Psychology Limited | Health & social care | 2006 |
| PV Transport Solutions Ltd | Transport & logistics | 2026 |
| PW Construction Ltd | Construction | 2025 |
| PW MNE Solutions Ltd | Construction | 2019 |
| Pwfl Limited | Health & social care | 2009 |
| PWH Building Limited | Construction | 2009 |
| PWH Construction Ltd | Construction | 2021 |
| Pwood Properties Ltd | Real estate | 2024 |
| PWS Legal Ltd | Professional & scientific | 2022 |
| PWS Property Management Limited | Real estate | 2024 |
| PX Alloys Ltd | Wholesale & retail | 2025 |
| PYE Hall Farms Limited | Agriculture & fishing | 2005 |
| PYM Quantum Ltd | Professional & scientific | 2025 |
| Pyramid Holdings Limited | Financial services | 2012 |
| Pyramid Paving Ltd | Construction | 2021 |
| Pyrofusion Limited | Construction | 2025 |
| PYS77 Ltd | Transport & logistics | 2019 |
| Pyzik Transport Ltd | Transport & logistics | 2021 |
| Q Bars & Restaurants Limited | Hospitality | 2010 |
| Q E Gate Residents Company Limited | Households | 2003 |
| Q Events Limited | Hospitality | 2022 |
| Q Painting Ltd | Construction | 2026 |
| Q Z Property Ltd | Real estate | 2022 |
| Q&C Products Europe Ltd | Wholesale & retail | 2018 |
| Qasim JAN Limited | Hospitality | 2021 |
| Qawit Ltd | Information & communication | 2025 |
| QC Civils Ltd | Construction | 2012 |
| QC Maintenance Ltd | Households | 2020 |
| Qconnect Communications Limited | Information & communication | 2025 |
| QIC Learn Ltd | Professional & scientific | 2017 |
| QMI (Holdings) Ltd | Extraterritorial | 2009 |
| Quad Vision Limited | Information & communication | 1994 |
| Quae Recta Tene Holdings Limited | Financial services | 2017 |
| Quaestus Yachts Ltd | Manufacturing | 1999 |
| Qualified Trade Services Limited | Administrative & support | 2006 |
| Quality Car Services Ltd | Other services | 2019 |
| Quality Education Consultants Ltd | Education | 2025 |
| Quality Electronic Designs Limited | Information & communication | 2005 |
| Quality Finish Pastry Ltd | Manufacturing | 2023 |
| Quality Finish Patisserie Limited | Manufacturing | 2006 |
| Quality Fire Protection Ltd | Professional & scientific | 2003 |
| Quality Gelato Limited | Administrative & support | 2018 |
| Quality Patient Solutions Ltd | Public administration | 2023 |
| Qualityres Ltd | Wholesale & retail | 2023 |
| Quandle Labs Limited | Information & communication | 2023 |
| Quantum Construction Limited | Construction | 2002 |
| Quantum CUT Ltd | Information & communication | 2024 |
| Quantum Growth International Ltd | Wholesale & retail | 2026 |
| Quantum Sphere Ltd | Information & communication | 2023 |
| Quarter Jack Park Management Company Limited | Households | 2023 |
| Quatro Properties Limited | Real estate | 2001 |
| Quatro Property 2 Limited | Real estate | 2024 |
| Quatro Property Limited | Professional & scientific | 2024 |
| Quavermouse Games Ltd | Information & communication | 2011 |
| Quay Land Ltd | Real estate | 2025 |
| Quay Marinas Group Ltd | Arts & recreation | 2003 |
| Quay Marinas Limited | Arts & recreation | 1973 |
| Quay Recruitment Group Limited | Administrative & support | 2017 |
| Quayline Digital Limited | Manufacturing | 2009 |
| Quayside Electrical Ltd | Construction | 2005 |
| Quayside Lettings Ltd | Real estate | 2014 |
| Quayside Renewables Limited | Construction | 2023 |
| Quayside View (Marchwood) NO. 1 Management Limited | Households | 1999 |
| Quayside View (Marchwood) NO. 2 Management Limited | Households | 2001 |
| Quayside View (Marchwood) NO.3 Management Limited | Households | 2001 |
| Quaysport Menorca Limited | Administrative & support | 2002 |
| QUE (UK) Ltd | Professional & scientific | 2006 |
| Queens Court Hill Lane Southampton Limited | Households | 1999 |
| Queens Court Management Limited | Households | 1980 |
| Quercus Projects Limited | Information & communication | 2003 |
| Querix (UK) Limited | Information & communication | 1994 |
| Querix Limited | Information & communication | 1994 |
| Quest ADA Ltd | Administrative & support | 2014 |
| Questmap Holdings Limited | Extraterritorial | 2018 |
| Quetta Tea Cafe Limited | Hospitality | 2026 |
| Quick Nautical Equipment Ltd | Manufacturing | 2018 |
| Quick Quote Roofing Ltd | Construction | 2025 |
| Quirk Marine Engineering Ltd | Manufacturing | 2021 |
| Quite Property Investment Limited | Real estate | 1997 |
| Quote My Builds Limited | Information & communication | 2021 |
| Quote My Renovations Limited | Information & communication | 2021 |
| Quraishe & Co Ltd | Real estate | 2025 |
| Qureshi Solutions Ltd | Financial services | 2026 |
| Qurvex Ltd | Information & communication | 2025 |
| Qwickhose Holdings Limited | Wholesale & retail | 2023 |
| Qwickhose Limited | Manufacturing | 2004 |
| R & a Networking Limited | Information & communication | 2003 |
| R & C Partnership Limited | Hospitality | 2023 |
| R & E Kitchen Care Limited | Health & social care | 2021 |
| R & F Weller Transport Limited | Transport & logistics | 2004 |
| R & K Properties South Ltd | Real estate | 2023 |
| R & L Properties (Southampton) Limited | Households | 2015 |
| R & M Freight (Southampton) Limited | Transport & logistics | 1993 |
| R & M Property Maintenance Ltd | Construction | 2007 |
| R & N Carpenters & Joiners Limited | Construction | 2002 |
| R & R Plumbing Ltd | Construction | 2010 |
| R & R Property Management Ltd | Real estate | 2024 |
| R & R Sports Coaching Ltd | Arts & recreation | 2009 |