| South Western House RTM Company Limited | Households | 2011 |
| Southagro Trading Ltd | Wholesale & retail | 2022 |
| Southampton Academy of Hospitality Ltd | Education | 2025 |
| Southampton Advice & Representation Centre | Other services | 2005 |
| Southampton Airport Taxis Ltd | Transport & logistics | 2024 |
| Southampton Area Co-Operative Development Agency | Administrative & support | 1986 |
| Southampton Assessment and Study Services Limited | Education | 2011 |
| Southampton Asset Management Limited | Financial services | 2002 |
| Southampton Athletic Futsal C.I.C. | Arts & recreation | 2025 |
| Southampton Autism Support Service Community Interest Company | Public administration | 2021 |
| Southampton Auto Hand Car Wash Ltd | Administrative & support | 2025 |
| Southampton Barbell Limited | Arts & recreation | 2016 |
| Southampton Barbers Limited | Other services | 2025 |
| Southampton Boat Club Limited | Education | 2018 |
| Southampton Builder Ltd | Construction | 2022 |
| Southampton Burger Ltd | Hospitality | 2025 |
| Southampton Business Improvement District Ltd | Administrative & support | 2017 |
| Southampton Butchers Limited | Wholesale & retail | 2008 |
| Southampton Cabs Limited | Transport & logistics | 2025 |
| Southampton Calor GAS Centre Limited | Extraterritorial | 2021 |
| Southampton Car Repair Ltd | Wholesale & retail | 2024 |
| Southampton Care Ltd | Health & social care | 2025 |
| Southampton Cargo Handling Limited | Transport & logistics | 1989 |
| Southampton Cars & Vans Ltd | Wholesale & retail | 2019 |
| Southampton Chauffeur Hire Limited | Transport & logistics | 2021 |
| Southampton Chiropractic Clinic Ltd | Health & social care | 2025 |
| Southampton Choral Society | Arts & recreation | 1981 |
| Southampton Citizens Advice Bureau | Other services | 2002 |
| Southampton City and Region, Action to Combat Hardship | Health & social care | 1999 |
| Southampton City Cleaning Company Ltd | Administrative & support | 2025 |
| Southampton City Rollers Limited | Arts & recreation | 2014 |
| Southampton Co-Operative Learning Trust | Education | 2011 |
| Southampton Construction Limited | Construction | 2009 |
| Southampton Container Services Ltd | Transport & logistics | 2020 |
| Southampton Cruise Concierge Limited | Administrative & support | 2014 |
| Southampton Cruise Parking (10 Princes Street) Ltd | Transport & logistics | 2025 |
| Southampton Cruise Parking Services Ltd | Other services | 2023 |
| Southampton Cruise Taxi Ltd | Transport & logistics | 2024 |
| Southampton Cruise Tours Limited | Transport & logistics | 2021 |
| Southampton Dielectric Consultants Limited | Professional & scientific | 2002 |
| Southampton Drives and Patios Ltd | Construction | 2020 |
| Southampton DRY Stack Limited | Transport & logistics | 2004 |
| Southampton Emporium Ltd | Wholesale & retail | 2025 |
| Southampton Energy Centre Limited | Health & social care | 2023 |
| Southampton Enterprise Centre Limited | Real estate | 2005 |
| Southampton Family Trust Ltd | Education | 2002 |
| Southampton FC Old Boys Association Limited | Other services | 2008 |
| Southampton Film Theatre | Arts & recreation | 1978 |
| Southampton Finance Limited | Administrative & support | 1995 |
| Southampton Financial Limited | Financial services | 2022 |
| Southampton Flower Walls & Events Limited | Wholesale & retail | 2020 |
| Southampton Food Buddies Limited | Hospitality | 2026 |
| Southampton Food Limited | Professional & scientific | 2025 |
| Southampton Football Club Limited | Arts & recreation | 1897 |
| Southampton Forward | Administrative & support | 2010 |
| Southampton Forward Trading Ltd | Administrative & support | 2024 |
| Southampton Freeholds Limited | Households | 2022 |
| Southampton Freight Services Limited | Transport & logistics | 1998 |
| Southampton Garden Supplies and Services Limited | Wholesale & retail | 2021 |
| Southampton GAS & Plumbing Ltd | Construction | 2013 |
| Southampton Girls and Women's Football Club Limited | Arts & recreation | 2009 |
| Southampton Grab Hire Limited | Water & waste | 2015 |
| Southampton Grain Terminal Limited | Extraterritorial | 1981 |
| Southampton Guesthouse Ltd | Hospitality | 2016 |
| Southampton Guildhall Coffee Limited | Hospitality | 2017 |
| Southampton Health International Limited | Financial services | 2026 |
| Southampton Health Limited | Extraterritorial | 2014 |
| Southampton Home Cleaning Services Ltd | Administrative & support | 2020 |
| Southampton Hospitals Charity | Health & social care | 2024 |
| Southampton House Removals Limited | Transport & logistics | 2024 |
| Southampton Hybrid Ltd | Wholesale & retail | 2025 |
| Southampton International Airport Limited | Transport & logistics | 1989 |
| Southampton International Arena Limited | Manufacturing | 2004 |
| Southampton International Boat Show Limited | Administrative & support | 1976 |
| Southampton K.H Limited | Hospitality | 2025 |
| Southampton Lettings Expert Limited | Real estate | 2025 |
| Southampton Lettings Ltd | Real estate | 2017 |
| Southampton Live Group Ltd | Hospitality | 2023 |
| Southampton Lodge Ltd | Real estate | 2020 |
| Southampton Lyndhurst Coffee Ltd | Hospitality | 2024 |
| Southampton Massage Limited | Health & social care | 2019 |
| Southampton Master Cleaners Ltd | Other services | 2014 |
| Southampton Medina Mosque Trust Limited | Other services | 2002 |
| Southampton Metals Limited | Manufacturing | 2018 |
| Southampton Mini Cabs Limited | Transport & logistics | 2025 |
| Southampton Motorcycle MOT Centre Ltd | Wholesale & retail | 2020 |
| Southampton Motorcycles and Scooters Ltd | Wholesale & retail | 2018 |
| Southampton Muslim Funeral Services Limited | Other services | 2020 |
| Southampton Noodle Limited | Hospitality | 2026 |
| Southampton Oval Lettings Limited | Extraterritorial | 2003 |
| Southampton Parent Carer Forum CIC | Information & communication | 2023 |
| Southampton Park and Cruise Limited | Transport & logistics | 2026 |
| Southampton Photogenic Ltd | Professional & scientific | 2013 |
| Southampton Physio Limited | Health & social care | 2024 |
| Southampton Pier Limited | Construction | 2011 |
| Southampton Portside Meet and Greet Ltd | Transport & logistics | 2025 |
| Southampton Portswood Coffee Limited | Hospitality | 2021 |
| Southampton Pride CIC | Arts & recreation | 2017 |
| Southampton Primary Care Limited | Health & social care | 2014 |
| Southampton Property Expert Limited | Real estate | 2024 |