| Bangla Birsto Ltd | Hospitality | 2025 |
| Banjokogee Lifestyle Ltd | Health & social care | 2025 |
| Banjokogee Media Ltd | Manufacturing | 2025 |
| Barakah Infused Career Coaching Ltd | Education | 2024 |
| Barakode Ltd | Information & communication | 2025 |
| Bargains R US Ltd | Wholesale & retail | 2017 |
| Barham Railway Limited | Manufacturing | 2016 |
| Barking Cinema Ltd | Arts & recreation | 2020 |
| Barking Motor Services Limited | Administrative & support | 2011 |
| Barrywills Accountants Limited | Professional & scientific | 2018 |
| Baruch Investment Holdings Limited | Real estate | 2026 |
| BAS 1 Embroidery & Printing Limited | Administrative & support | 2005 |
| BAS 1 Group Ltd | Financial services | 2024 |
| Basicz Ltd | Wholesale & retail | 2025 |
| Basket Marketplace Ltd | Wholesale & retail | 2023 |
| Bata Shoes Ltd | Manufacturing | 2025 |
| Batalov Services Limited | Administrative & support | 2016 |
| Bawrj Property Limited | Real estate | 2024 |
| Baxy Construction Ltd | Construction | 2017 |
| Bay Lake Media Ltd | Information & communication | 2010 |
| Baylash Private Ltd | Construction | 2012 |
| BBQ Burrito Ltd | Hospitality | 2023 |
| BC Asset Co Limited | Financial services | 2022 |
| BCT Annie Limited | Professional & scientific | 2021 |
| BDG Fiduciary Services Limited | Administrative & support | 2017 |
| Beacon Construction Services Ltd | Professional & scientific | 2018 |
| Beam MOT Centre Limited | Wholesale & retail | 2023 |
| Beam Park Childcare Limited | Health & social care | 2024 |
| Beam Reach 8A Management Limited | Real estate | 2012 |
| Beam Test Centre Ltd | Wholesale & retail | 2019 |
| Bearcat Limited | Construction | 2009 |
| Beatison Properties Ltd | Real estate | 2024 |
| Beauty Dolls of Essex Ltd | Wholesale & retail | 2021 |
| Beautyfix Wholesale Ltd | Wholesale & retail | 2023 |
| Beckett Bloomfield Legal Services Ltd | Professional & scientific | 2018 |
| Believers Loveworld Limited | Manufacturing | 2014 |
| Belito Limited | Wholesale & retail | 2018 |
| Bellstone Furniture Distributors Limited | Transport & logistics | 2025 |
| Beltap Capital Limited | Financial services | 2020 |
| BEM Projects Ltd | Construction | 2025 |
| BEN Swift Courier Ltd | Transport & logistics | 2024 |
| Benedict Bretts (UK) Ltd | Other services | 2021 |
| Benevelent Ltd | Health & social care | 2025 |
| Bengal Spice (Rainham) Ltd | Hospitality | 2024 |
| Benise Limited | Health & social care | 2024 |
| Beqa Services UK Ltd | Construction | 2023 |
| Berwen Limited | Real estate | 1946 |
| Berwick Manor Lounge Limited | Hospitality | 2025 |
| Beryl Life Ltd | Health & social care | 2023 |
| Bescience Stem C.I.C. | Administrative & support | 2016 |
| Bespoke Detailers Limited | Administrative & support | 2023 |
| Bespoke Estate Management Ltd | Construction | 2022 |
| Bessy Construction Ltd | Construction | 2023 |
| Best Alternative Services Ltd | Arts & recreation | 2012 |
| Best Flight Cases Limited | Manufacturing | 2015 |
| Best Food Legacy Ltd | Hospitality | 2025 |
| Besteuropean Tools Limited | Manufacturing | 2025 |
| Bestflightcasesonline Ltd | Manufacturing | 2024 |
| Besto 44 Ltd | Wholesale & retail | 2019 |
| Betaplus International Synergy Limited | Financial services | 2024 |
| BF Global Investment Limited | Real estate | 2023 |
| Bhavnit Limited | Wholesale & retail | 2021 |
| BI2YOU Limited | Information & communication | 2017 |
| Bibsea Construction and Cleaning Limited | Construction | 2024 |
| Bibsea Limited | Health & social care | 2013 |
| Bibv Constructions Ltd | Construction | 2025 |
| Bics Electrical Ltd | Construction | 2019 |
| Big Dave's MAN Caves Ltd | Construction | 2021 |
| Big Hill International Limited | Real estate | 2024 |
| Big Tree Group Limited | Information & communication | 2019 |
| Bigbillion Food & Beverages Limited | Hospitality | 2022 |
| BIGSELLER2020UK Ltd | Wholesale & retail | 2023 |
| Billie Box Ltd | Wholesale & retail | 2012 |
| Billie’S Blooms Ltd | Wholesale & retail | 2024 |
| Billionaires Team Ltd | Wholesale & retail | 2025 |
| Biosun Services (UK) Limited | Extraterritorial | 2014 |
| Bist Properties Limited | Real estate | 2022 |
| BIT Bubbles Ltd | Wholesale & retail | 2026 |
| Bizgrow Holdings Ltd | Professional & scientific | 2022 |
| Bizplus Consultancy Services Ltd | Professional & scientific | 2013 |
| BK90 Restaurant & Lounge Limited | Hospitality | 2022 |
| Bkmc Limited | Wholesale & retail | 2024 |
| Bkpb Civil Engineering SE Ltd | Construction | 2023 |
| Black Heart 74 Ltd | Manufacturing | 2023 |
| Black Line Limited | Arts & recreation | 2014 |
| Black Shark Investments Limited | Hospitality | 2025 |
| Black Stone Financial Limited | Other services | 2022 |
| Black Stone Utility Limited | Other services | 2022 |
| Blackfox Security Limited | Administrative & support | 2024 |
| Blackthorn Business Limited | Wholesale & retail | 2020 |
| Blara Group Limited | Construction | 2010 |
| Blara Safety UK Limited | Construction | 2007 |
| Blazing Bowls Ltd | Wholesale & retail | 2021 |
| Blessed Hands Ventures Ltd | Health & social care | 2023 |
| Blink Construction Limited | Construction | 2020 |
| Bliwsky Ltd | Information & communication | 2022 |
| Blomiki Limited | Administrative & support | 2026 |
| Bloombeck Ltd | Real estate | 2016 |
| Bloomsfield OIL and GAS Limited | Professional & scientific | 2025 |
| Bloomsfield Properties & Investment Group Ltd | Real estate | 2025 |