| B2B Renewables and Transport Ltd | Transport & logistics | 2024 |
| B2L Realty Ltd | Real estate | 2025 |
| BA Barbers Ltd | Other services | 2019 |
| Babs Consultants Limited | Professional & scientific | 2020 |
| Babs Legacy Limited | Wholesale & retail | 2024 |
| Bacchus Productions Ltd | Information & communication | 2024 |
| BACK2ROOTSUK Limited | Manufacturing | 2022 |
| Backpost Productions Limited | Professional & scientific | 2012 |
| Badhwar & Sons Ltd | Wholesale & retail | 2025 |
| Badshaws Limited | Wholesale & retail | 2024 |
| Baduism Ltd | Professional & scientific | 2022 |
| BAG IT Packaging Limited | Other services | 2010 |
| Bailey Accountancy & Book-Keeping Ltd | Professional & scientific | 2014 |
| Bailey Accountancy Services Ltd | Professional & scientific | 2011 |
| Bailey Book-Keeping Services Ltd | Professional & scientific | 2007 |
| Bailey Consultant Services Limited | Professional & scientific | 2025 |
| Bailey Distribution Services Ltd | Extraterritorial | 2011 |
| Bailey Group (UK) Ltd | Extraterritorial | 2011 |
| Baileys Court Management Company Limited | Households | 2003 |
| Bakers Farm Barns Ltd | Real estate | 2021 |
| Baldoyle Investments Ltd | Real estate | 2013 |
| Baldwins Leisure Limited | Real estate | 2023 |
| Bali HAI Kennels Ltd | Other services | 2023 |
| Balinga Consulting Limited | Professional & scientific | 2019 |
| Balkan Burgers Ltd | Manufacturing | 2025 |
| Balkan Shawarma 100 Ltd | Hospitality | 2026 |
| Ball Protection Limited | Financial services | 2024 |
| Ballaz in DA Middle Foundation C.I.C. | Education | 2022 |
| Ballaz in DA Middle Ltd | Information & communication | 2022 |
| Ballet Folk Limited | Education | 2019 |
| Ballingdon Shop Ltd | Wholesale & retail | 2022 |
| Ballows Ltd | Real estate | 2024 |
| Balm of G Ltd | Real estate | 2022 |
| Balm of Gilead Consultancy Limited | Health & social care | 2011 |
| Bamboo Music Management Limited | Arts & recreation | 2014 |
| Bamidele Ltd | Health & social care | 2025 |
| Bandi-Coot Group Ltd | Wholesale & retail | 2020 |
| Bannerbrook Park (Phase 1B) Management Company Limited | Households | 2007 |
| Banter Boys Limited | Information & communication | 2026 |
| Barber Reece Ltd | Other services | 2024 |
| Barenreiter Limited | Information & communication | 1963 |
| Bari and Asghar Properties Limited | Real estate | 2025 |
| Barking BG Limited | Real estate | 2022 |
| Barn Street Yard Management Company Limited | Households | 2015 |
| Barnce Heritage Ltd | Wholesale & retail | 2026 |
| Barnes Carpets of Harlow Ltd | Construction | 2025 |
| Barnet Market Ltd | Other services | 2021 |
| Barriers and Bollards Direct Limited | Professional & scientific | 2009 |
| Barriers Direct Limited | Professional & scientific | 2009 |
| Barringtons Coal Merchants Limited | Wholesale & retail | 2013 |
| Barrow Creative Limited | Professional & scientific | 2025 |
| Bartons Court Management Limited | Households | 2002 |
| Bartontek Limited | Professional & scientific | 2015 |
| Basclef Properties Ltd | Real estate | 2023 |
| Basclef Specialist Healthcare Ltd | Health & social care | 2010 |
| Base Central NW1 Management Company Limited | Households | 2002 |
| Baseda Group Ltd | Health & social care | 2022 |
| Basicord Healthcare Services Ltd | Health & social care | 2025 |
| Basics and Beyond Football Coaching Ltd | Education | 2026 |
| Bass &Tenor Ltd | Information & communication | 2016 |
| Bassi Bookkeeping Ltd | Professional & scientific | 2018 |
| Bassi Business Solutions Limited | Professional & scientific | 2014 |
| Bassi Financial Consulting Limited | Professional & scientific | 2023 |
| Bastion House (Amhurst Road) Management Company Limited | Households | 2021 |
| Bathroom Lighting Limited | Wholesale & retail | 2001 |
| Batomak Ltd | Professional & scientific | 2024 |
| Battle Masters Essex Limited | Arts & recreation | 2021 |
| Baysworth Medical Consult Limited | Health & social care | 2023 |
| Bbme Group Ltd | Information & communication | 2023 |
| Bbqsim Ltd | Hospitality | 2026 |
| BBU Film Limited | Information & communication | 2022 |
| Bcare Services Ltd | Health & social care | 2021 |
| Bceve Limited | Health & social care | 2016 |
| BCJ Wall Cladding Ltd | Construction | 2026 |
| BCM & Resilience Solutions Ltd | Professional & scientific | 2020 |
| BD Commercial Finishes Ltd | Construction | 2018 |
| BD Construction Services Ltd | Construction | 2020 |
| BD Creative Solutions Limited | Construction | 2013 |
| Bdeco Limited | Construction | 2016 |
| Bdja Ltd | Construction | 2026 |
| BDN Logistics UK Ltd | Transport & logistics | 2025 |
| BE Naturally Healthy Limited | Other services | 2019 |
| BE That Girl Ltd | Wholesale & retail | 2020 |
| Beachtree Limited | Professional & scientific | 1999 |
| Beacon Finance B2B Ltd | Other services | 2025 |
| Beadles Parade Ltd | Wholesale & retail | 2025 |
| Beagley Enterprises Ltd | Real estate | 2022 |
| Beam Culture Ltd | Professional & scientific | 2026 |
| Bear BLU Rugby Limited | Arts & recreation | 2016 |
| Bear BRO Carpentry Ltd | Manufacturing | 2017 |
| Bearing and Engineering Sales (Harlow) Limited | | 1987 |
| Bearswood Ltd | Real estate | 1960 |
| Beatrice Manjonjo Limited | Health & social care | 2012 |
| Beauty in Community CIC | Administrative & support | 2020 |
| Beauty Infusions London Ltd | Other services | 2018 |
| Beauty Lounge at the Base Ltd | Other services | 2020 |
| Beauty Lounge by a Ltd | Health & social care | 2016 |
| Beauty Scripts Aesthetics Limited | Other services | 2025 |
| BECKMAN1959 Ltd | Transport & logistics | 2025 |
| BEE HR Solutions Ltd | Health & social care | 2025 |