| Barber Plumbing Solutions Limited | Construction | 2018 |
| Barber Real Estate Limited | Real estate | 2018 |
| Barbie Beauty Limited | Other services | 2020 |
| Barboza Logistics Ltd | Transport & logistics | 2025 |
| Barc Production Services Ltd | Information & communication | 2019 |
| Barcelona Productions Limited | Other services | 1997 |
| Barchest Limited | Information & communication | 2017 |
| Barclay Building Contractors Limited | Construction | 2002 |
| Barco Estates Management Ltd | Real estate | 2023 |
| Barcode LDN Ltd | Wholesale & retail | 2018 |
| Barcoleon FX Limited | Education | 2018 |
| Bard Management Limited | Households | 2011 |
| Bardon & Lannister Investments Ltd | Financial services | 2025 |
| Barewood Residential Ltd | Construction | 2021 |
| Bargain Hub Limited | Wholesale & retail | 2011 |
| BARGAINS4BUY UK Ltd | Wholesale & retail | 2025 |
| Barima Ltd | Information & communication | 2015 |
| Barini Services Ltd | Construction | 2026 |
| Baritec Ltd | Information & communication | 2013 |
| Barking Baths Ltd | Other services | 2024 |
| Barlas Partners Ltd | Health & social care | 2024 |
| Barletone Plastering Limited | Construction | 2023 |
| Barn Hill Construction and Development Limited | Construction | 2015 |
| Barnaby Taylor Music Limited | Information & communication | 2009 |
| Barnet & Enfield Hygiene Services Ltd | Administrative & support | 2025 |
| Barnet Motor Medics Limited | Wholesale & retail | 2018 |
| Barnet Smiles Dental Care Limited | Health & social care | 2010 |
| Barnett and Co Accountants Limited | Professional & scientific | 2016 |
| Barneyquin Digital Media Limited | Professional & scientific | 2025 |
| Barngold Ltd | Professional & scientific | 2002 |
| Barnlodge Limited | Construction | 2015 |
| Barnpine Limited | Real estate | 2005 |
| Baron Bird Ltd | Real estate | 2017 |
| Baronessa Limited | Wholesale & retail | 2009 |
| Barons Electrical Ltd | Construction | 2025 |
| Barrat M&E Limited | Administrative & support | 2019 |
| Barrel Proof Distribution Ltd | Wholesale & retail | 2020 |
| Barrett Tomes Limited | Information & communication | 2022 |
| Barrie Pallen Associates (UK) Limited | Administrative & support | 2011 |
| Barrington Stores Limited | Wholesale & retail | 2017 |
| Barrow Lane Management Limited | Financial services | 2010 |
| Barrowdrive Limited | Wholesale & retail | 2010 |
| Barrowfen Properties Limited | Real estate | 1984 |
| Barry Drinks Ltd | Wholesale & retail | 2013 |
| Barry Masterful Limited | Information & communication | 2020 |
| Bars Across Ltd | Information & communication | 2026 |
| Barst Management Resources Limited | Professional & scientific | 2008 |
| Bart UK Trans Ltd | Transport & logistics | 2021 |
| Bart UK Transport Ltd | Transport & logistics | 2018 |
| Bartholomew Court Residents Limited | Households | 1997 |
| Bartolo AI Limited | Information & communication | 2019 |
| Barton Lodge Ltd | Health & social care | 2023 |
| Barton Oncology Limited | Health & social care | 2004 |
| Barylphoto UK Limited | Wholesale & retail | 2026 |
| BAS Acquisitions Ltd | Real estate | 2021 |
| BAS Holdings Ltd | Real estate | 2015 |
| BAS Media Ltd | Information & communication | 2020 |
| BAS Venture Capital Ltd | Financial services | 2024 |
| Basa Partners Limited | Wholesale & retail | 2013 |
| Basch & Rameh LLP | | 2012 |
| Baseline Creative Media Ltd | Information & communication | 2021 |
| Basetrade Services Limited | Professional & scientific | 2002 |
| Basewell Investments Limited | Construction | 2015 |
| Basic Ayurveda Ltd | Wholesale & retail | 2011 |
| Basingstoke HCW Ltd | Other services | 2012 |
| Basingstoke Supplementary Islamic School CIC | Education | 2024 |
| Basis Distribution Ltd | Administrative & support | 2014 |
| BASK8 Limited | Wholesale & retail | 2011 |
| Basri Elite Limited | Wholesale & retail | 2025 |
| Bass Notes Coffee Ltd | Hospitality | 2021 |
| Bassam Cargo Ltd | Wholesale & retail | 2023 |
| Bassett Consulting Services Limited | Administrative & support | 2011 |
| Bassini Accessories Limited | Wholesale & retail | 2022 |
| Bassini Antiques Limited | Wholesale & retail | 2026 |
| Bassini Art and Sports Sculptures Limited | Arts & recreation | 2026 |
| Bassini Asset Finance Co. Limited | Administrative & support | 2020 |
| Bassini Beauty Nails and Pedicure Shops Limited | Other services | 2026 |
| Bassini Board Limited | Professional & scientific | 2022 |
| Bassini Body Shops Limited | Wholesale & retail | 2022 |
| Bassini Cakes Limited | Wholesale & retail | 2022 |
| Bassini Classic Cars Limited | Wholesale & retail | 2022 |
| Bassini Clothing Fashion Limited | Wholesale & retail | 2022 |
| Bassini Co. Ltd | Construction | 2020 |
| Bassini Cosmetics Limited | Wholesale & retail | 2022 |
| Bassini DRY Cleaners Limited | Other services | 2026 |
| Bassini E Bikes Worldwide Limited | Administrative & support | 2026 |
| Bassini Handbags Limited | Wholesale & retail | 2022 |
| Bassini Perfumes Limited | Wholesale & retail | 2022 |
| Bassini Pizza Limited | Hospitality | 2022 |
| Bassini Property Investments Limited | Real estate | 2018 |
| Bassini Spas Limited | Other services | 2022 |
| Bassini Special Board of Integrity, Values and Honesty Limited | Professional & scientific | 2026 |
| Bassini Sweets and Chocolates Limited | Hospitality | 2022 |
| Bassini Watches Company Limited | Manufacturing | 2026 |
| Bassini West END Lettings Limited | Real estate | 2022 |
| Bassini’S Bakeries Limited | Manufacturing | 2020 |
| Bassini’S Chauffeuring Limited | Transport & logistics | 2020 |
| Bassini’S Entertainments Limited | Arts & recreation | 2020 |
| Bassini’S Soup Kitchen for the Homeless and Vulnerable People Limited | Health & social care | 2022 |
| Basstone Music Limited | Information & communication | 2020 |