| B L Hill Ltd | Real estate | 2025 |
| B M and Sons Limited | Real estate | 2019 |
| B M Events & Shows Limited | Arts & recreation | 2018 |
| B Ross Electrical Services Ltd | Construction | 2018 |
| B Thompson Engineering Ltd. | Manufacturing | 2016 |
| B&C Façade Management Limited | Construction | 2026 |
| B&G Infrastructure Supplies Ltd | Wholesale & retail | 2025 |
| B&K Building Ltd | Construction | 2024 |
| B&K Pubs Ltd | Hospitality | 2017 |
| B&M Roundhouse Services Ltd | Construction | 2023 |
| B&N Builders Southern Limited | Construction | 2022 |
| B.A.R.S. Brooker Ltd | Hospitality | 2025 |
| B.Eastman Plumbing & Heating Limited | Construction | 2019 |
| B.I. Wall Big Rides Limited | Arts & recreation | 2004 |
| B.J.H. Windows Limited | Construction | 1987 |
| B.J.M.(Upholstery)Limited | Manufacturing | 1966 |
| B.K. Residential Developments Limited | Construction | 2007 |
| B.More Solent CIC | Health & social care | 2026 |
| B.P.A.C. Holdings Limited | Financial services | 2015 |
| B3 Passenger Care Ltd | Health & social care | 2018 |
| B3D1R3 Ltd | Wholesale & retail | 2024 |
| BA Technologies Limited | Professional & scientific | 2017 |
| Babale Ltd | Wholesale & retail | 2026 |
| Baby B (Portsmouth) Ltd | Wholesale & retail | 2020 |
| Babylon Shawarma 1 Ltd | Hospitality | 2026 |
| Bacaro Restaurants Ltd | Hospitality | 2016 |
| Back Office Trust and Wills Limited | Financial services | 2025 |
| Back to Basics Furniture Limited | Manufacturing | 2012 |
| Back to Fitness Limited | Arts & recreation | 2005 |
| Badgie-Bassen Ltd | Transport & logistics | 2025 |
| Baffins Builders Limited | Construction | 2011 |
| Baffins Hand Car Wash Ltd | Other services | 2019 |
| Baffins Properties Limited | Real estate | 2018 |
| Bageld Ltd | Extraterritorial | 2020 |
| Baggott & Sons (Southern) Limited | Construction | 2019 |
| Baggott & Sons Holdings Limited | Construction | 2020 |
| Bailando Journey Ltd | Arts & recreation | 2020 |
| Bailey Property Developments Ltd | Construction | 2024 |
| Bailey Thomson Limited | Real estate | 2018 |
| Baileys Roofing Ltd | Construction | 2024 |
| Baja Mexicali (Portsmouth) Ltd | Hospitality | 2022 |
| Baker Building Renovations Limited | Construction | 2021 |
| Bala T V G Limited | Professional & scientific | 2013 |
| Balance & Skin Ltd | Wholesale & retail | 2026 |
| Balance Wellness Club Ltd | Arts & recreation | 2024 |
| Balanced Performance Ltd | Information & communication | 2026 |
| Bale GAS Ltd | Construction | 2013 |
| Bale Plumbing & Heating Ltd | Construction | 2026 |
| Balfour Landscapes Ltd | Administrative & support | 2013 |
| Balfourkerr Group Limited | Financial services | 2014 |
| Balfourkerr Properties Limited | Real estate | 1997 |
| Balmoral Flooring Limited | Wholesale & retail | 2004 |
| Balmoral Timber Preservation (Salisbury) Limited | Wholesale & retail | 1985 |
| BAM Housing Limited | Real estate | 2017 |
| Bamis Limited | Extraterritorial | 2008 |
| Bandeja Holdings Ltd | Professional & scientific | 2024 |
| Banfes Limited | Education | 2025 |
| Bangla Society Portsmouth (BSP) Ltd Ltd | Other services | 2025 |
| Bangla Society Portsmouth Ltd | Other services | 2022 |
| Bangxon Limited | Wholesale & retail | 2010 |
| Baobab Services Ltd | Administrative & support | 2015 |
| BAP Investments Ltd | Real estate | 2024 |
| Bar Aroma Ltd | Hospitality | 2022 |
| Bar Construction (South) Ltd | Construction | 2009 |
| Barbara Tipple Jewellers Limited | Manufacturing | 2016 |
| Barbarian Facilities Management Limited | Administrative & support | 2024 |
| Barber Fade Zone Ltd | Other services | 2022 |
| Barber French Associates Limited | Administrative & support | 2009 |
| Barbiero Limited | Other services | 2020 |
| Bardar Ltd | Health & social care | 2013 |
| Bardgrange Limited | Construction | 1985 |
| Bare Clinic Ltd | Other services | 2024 |
| Bargate Homes Limited | Construction | 2005 |
| Bargate SPV1 Limited | Construction | 2012 |
| Barhill Plant Limited | Construction | 1973 |
| Barnden Financial Services Ltd | Financial services | 2010 |
| Barnsley Vehicle Logistics Ltd | Transport & logistics | 2014 |
| Barttelot & Ward Electrical Services Ltd | Construction | 2023 |
| Barwood Kidbrook LLP | | 2018 |
| Base Nutrition Ltd | Health & social care | 2024 |
| Basil & Joy Limited | Transport & logistics | 2021 |
| Basins, Baths and Showers Ltd | Wholesale & retail | 2011 |
| Basmati Locks Heath Limited | Hospitality | 2013 |
| Bastile Contracts Ltd. | Construction | 2014 |
| Battersea Primary Care Network Limited | Health & social care | 2022 |
| Battle City Games Ltd | Wholesale & retail | 2023 |
| Battlezone Limited | Professional & scientific | 1992 |
| Baydeck Ltd | Real estate | 2021 |
| Bays Energy Ltd | Professional & scientific | 2025 |
| Bayside Events Ltd | Hospitality | 2024 |
| Baytech Europe Limited | Wholesale & retail | 2008 |
| Bayview Bathrooms Ltd | Construction | 2021 |
| BB Housing Solutions Ltd | Real estate | 2021 |
| BB Storage (South) Ltd | Transport & logistics | 2020 |
| BBB Bournemouth Limited | Hospitality | 2021 |
| BC Developments & Drylining Ltd | Construction | 2024 |
| Bc&A Legal Services Ltd | Professional & scientific | 2019 |
| BCA Consulting Limited | Real estate | 2017 |
| Bcdiving Limited | Information & communication | 2008 |
| BCH Fire Protection Ltd | Public administration | 2026 |