| A Courtney Electrical Services Ltd | Construction | 2019 |
| A D Green Building Ltd | Construction | 2025 |
| A D Leadwork Limited | Construction | 2010 |
| A E Renewables Ltd | Construction | 2017 |
| A Fothergill Home Improvements Ltd | Construction | 2021 |
| A G C Property Services Limited | Construction | 2017 |
| A G Carpentry Southern Limited | Construction | 2018 |
| A G Developments (Solent) Limited | Construction | 2007 |
| A G Leaves Building Services Limited | Construction | 2014 |
| A J & M J Plant (Sales) Limited | Wholesale & retail | 1996 |
| A J Decorating Services Limited | Construction | 2014 |
| A J G Lifts Ltd | Professional & scientific | 2022 |
| A J L Installation Limited | Professional & scientific | 2018 |
| A J Price Lifting Ltd | Construction | 2017 |
| A JC Auto Solutions Ltd | Wholesale & retail | 2025 |
| A K R Emporium Limited | Wholesale & retail | 2021 |
| A M Stubbs Limited | Health & social care | 2008 |
| A Parker Solutions Ltd | Construction | 2013 |
| A Peach Holdings Limited | Real estate | 2004 |
| A S Football Academy Limited | Arts & recreation | 2015 |
| A Square TV Ltd | Professional & scientific | 2021 |
| A Styles Consulting Ltd | Information & communication | 2024 |
| A T 5 Carpentry Limited | Construction | 2021 |
| A Team Coving Limited | Construction | 2018 |
| A to Z Construction (Southern) Ltd | Construction | 2023 |
| A Touch of Limited | Professional & scientific | 2021 |
| A Van Portsmouth Limited | Transport & logistics | 2013 |
| A W Electrical Contractors Limited | Construction | 2006 |
| A W P Surfacing Ltd | Construction | 2023 |
| A X L Transfers Ltd | Transport & logistics | 2023 |
| A&D Dragons Bros Limited | Information & communication | 2025 |
| A&D Pretty Savage Ltd | Information & communication | 2026 |
| A&G Caravan Service and Repair Ltd | Manufacturing | 2021 |
| A&H Installations Ltd | Construction | 2018 |
| A&M Science Limited | Health & social care | 2023 |
| A&N Construction Services Ltd | Construction | 2021 |
| A&N Portsmouth LLP | | 2025 |
| A&Pkurup Ltd | Health & social care | 2020 |
| A&R Cargo Solutions Limited | Transport & logistics | 2025 |
| A&W Consultancy Services Ltd | Information & communication | 2019 |
| A-List Accounting Ltd | Professional & scientific | 2025 |
| A-N-R Services Ltd | Construction | 2021 |
| A.D.B Plumbing & Heating Ltd | Construction | 2024 |
| A.D.B. Projects Limited | Construction | 2008 |
| A.D.P. Management Ltd | Construction | 2003 |
| A.D.X Precision Engineering Limited | Manufacturing | 1999 |
| A.G. Connections Ltd | Construction | 2022 |
| A.G. Phillips & SON Limited | Agriculture & fishing | 1981 |
| A.S.C Cableing Ltd. | Information & communication | 2013 |
| A.S.E. Developments Limited | Construction | 2022 |
| A.S.G. Crumbs Limited | Wholesale & retail | 2014 |
| A1 Heavenly Homes Limited | Real estate | 2024 |
| A1 Print Services Limited | Manufacturing | 2018 |
| AA Crookhorn Limited | Hospitality | 2026 |
| AAA Drainage Limited | Other services | 2018 |
| AAA Roofing Solutions Ltd | Construction | 2024 |
| AAB Property Holdings Ltd | Real estate | 2023 |
| Aabrows Limited | Other services | 2019 |
| AAC Digital Ltd | Information & communication | 2022 |
| Aamt Properties Ltd | Real estate | 2025 |
| Aaroncam Limited | Information & communication | 2017 |
| Aath Construction & Development Ltd | Construction | 2012 |
| Aayg Ltd | Professional & scientific | 2011 |
| AB Catering (Hampshire) Ltd | Hospitality | 2021 |
| AB Consultancy (Southern) Ltd | Professional & scientific | 2018 |
| ABA OIL Limited | Mining & quarrying | 2019 |
| Abaci Consulting Limited | Professional & scientific | 2013 |
| Abacus Energy (UK) Ltd | Professional & scientific | 2011 |
| Abbey Asia Limited | Hospitality | 2023 |
| Abbey Trading Group Limited | Wholesale & retail | 2022 |
| ABC Accountants Limited | Professional & scientific | 2004 |
| ABC Projects (Southern) Limited | Financial services | 2005 |
| Abeco Interiors Ltd | Construction | 2025 |
| Abel Housing Services Limited | Construction | 2023 |
| Abel Projects Limited | Construction | 2012 |
| Abella Entertainment Ltd | Arts & recreation | 2024 |
| ABH Surgery Limited | Health & social care | 2023 |
| ABI Peters Aesthetics Ltd | Health & social care | 2025 |
| Abitia Ltd | Construction | 2024 |
| ABL Group Ltd | Real estate | 2024 |
| Abode Legal Consultancy Limited | Professional & scientific | 2021 |
| ABS South Ltd | Construction | 2025 |
| Absolute Autos Locksmith Ltd | Wholesale & retail | 2019 |
| Absolute Autos Waterlooville Limited | Wholesale & retail | 2013 |
| Absolute Mods Ltd | Information & communication | 2022 |
| Absorbawall Limited | Wholesale & retail | 2019 |
| ABV Rentals Limited | Administrative & support | 2017 |
| ABZ Jetting Services Limited | Administrative & support | 2025 |
| AC Laminators Ltd | Manufacturing | 2025 |
| AC Landrover Specialist Ltd | Wholesale & retail | 2019 |
| Acacia Project Consultancy Limited | Construction | 2026 |
| Academy HR Limited | Administrative & support | 2026 |
| Access Social Work Limited | Health & social care | 2022 |
| ACCESS2INDEPENDENCE Limited | Health & social care | 2019 |
| Accessories Mart Limited | Wholesale & retail | 2019 |
| Acchah C.I.C. | Wholesale & retail | 2023 |
| Accident Repair Finder Limited | Other services | 2008 |
| Accord Technical & Security Limited | Administrative & support | 2004 |
| Accountability Recruitment Southern Ltd | Administrative & support | 2024 |
| Accountants ARE NOT ALL Boring Limited | Professional & scientific | 2014 |