| Barbacuti Construction Ltd | Construction | 2019 |
| Barber Ciao Ltd | Other services | 2025 |
| Barbercloud Ltd | Information & communication | 2020 |
| Barkat Trading Limited | Wholesale & retail | 2011 |
| Barkers Maintenance Ltd | Administrative & support | 2020 |
| Barkers Property Maintenance Ltd | Administrative & support | 2020 |
| Barking Heights Ltd | Administrative & support | 2016 |
| Barrah Limited | Real estate | 2020 |
| Barthas Fitness Wear Innovation Ltd | Wholesale & retail | 2025 |
| Basal Harry Ltd | Transport & logistics | 2017 |
| Basar Holdings Limited | Financial services | 2024 |
| Basf Traders Limited | Wholesale & retail | 2025 |
| Bashir Halal Meat Ltd | Wholesale & retail | 2022 |
| Bassett's Stonework Ltd | Manufacturing | 2025 |
| Battersea Logistics Ltd | Transport & logistics | 2022 |
| BAW Consultancy Ltd | Administrative & support | 2017 |
| Baxter & Black Ltd | Professional & scientific | 2021 |
| Bayfinch Holidays UK Ltd | Administrative & support | 2023 |
| Bayleaf Services Ltd | Construction | 2005 |
| Bayrony Import & Export UK Limited | Wholesale & retail | 2024 |
| Bbamo.Uk Limited | Wholesale & retail | 2025 |
| Bcde CIC | Public administration | 2025 |
| BD Renovations Ltd | Construction | 2016 |
| Beadle Business Limited | Arts & recreation | 2022 |
| Beardell Properties Ltd | Real estate | 2022 |
| Beautifier Ltd | Wholesale & retail | 2009 |
| Beauty Junction Ltd | Wholesale & retail | 2013 |
| Bebo 2 Limited | Other services | 2018 |
| Becks & Family Limited | Health & social care | 2019 |
| Becks Properties Limited | Real estate | 2025 |
| Beirutimes UK Limited | Wholesale & retail | 2022 |
| Bekspoke Decor Specialists Ltd | Construction | 2013 |
| Belaju Cafe Delicatessen Limited | Hospitality | 2014 |
| Belgrave Supplies Ltd | Hospitality | 2013 |
| Bella ME Medaesthetics Limited | Health & social care | 2018 |
| Bella Sposa Ltd | Manufacturing | 2026 |
| Belladona Limited | Hospitality | 2017 |
| Belleric Ltd | Information & communication | 2013 |
| Bells Electrical Services Ltd | Construction | 2019 |
| Bells Elite Ltd | Real estate | 2025 |
| Benli Estates Ltd | Real estate | 2023 |
| Berg Bespoke Ltd | Construction | 2022 |
| Berkeley Private Wealth Ltd | Financial services | 2015 |
| Berlin Padel Limited | Wholesale & retail | 2026 |
| BERMONDSEYBOY1 Limited | Manufacturing | 2022 |
| Berners Developments Ltd | Construction | 2018 |
| Besafe Cybersecurity Ltd | Manufacturing | 2025 |
| Bespa Service Ltd | Transport & logistics | 2023 |
| Bespoke Music Ltd | Information & communication | 2025 |
| Bespoke Services London Ltd | Transport & logistics | 2014 |
| Bessa Studio Ltd | Information & communication | 2025 |
| Best Fish and Chippy Ltd | Hospitality | 2026 |
| Best Food Services Ltd | Hospitality | 2020 |
| Best Grill London Limited | Hospitality | 2019 |
| Best in Town Network Ltd | Professional & scientific | 2026 |
| Best Maintenance Ltd | Construction | 2016 |
| Best Value Roofing Ltd | Construction | 2025 |
| Bestbuy Retail Trading Ltd | Wholesale & retail | 2020 |
| Bestbuy Shopfitters Limited | Construction | 2014 |
| Beulah Road Ltd | Real estate | 2020 |
| Beveridge Fernandez-Garcia Ltd | Information & communication | 2013 |
| Beyond Brushes Decor Ltd | Construction | 2026 |
| BFK Assets Limited | Real estate | 2026 |
| BGB Builders Ltd | Construction | 2016 |
| BGS UK Properties Limited | Real estate | 2020 |
| BHL Plumbing & Heating Limited | Construction | 2009 |
| Bhullar Security Company Ltd | Administrative & support | 2026 |
| BI Pro Consulting Ltd | Professional & scientific | 2022 |
| Biatherm Solutions Ltd | Manufacturing | 2026 |
| Bibliopolae Limited | Wholesale & retail | 2026 |
| Bidpro Ltd | Wholesale & retail | 2020 |
| Big DO London Limited | Hospitality | 2023 |
| Bigorre Aviation Ltd | Wholesale & retail | 2019 |
| Bike Nuts Company Limited | Wholesale & retail | 2019 |
| Bike Repair & FIX Ltd | Wholesale & retail | 2018 |
| Bike Sales & Repairs Ltd | Wholesale & retail | 2017 |
| Biowealth Limited | Wholesale & retail | 2025 |
| Biryani Buds Ltd | Hospitality | 2025 |
| Bishopsford House Owners Limited | Households | 2017 |
| Biyaz Business Solutions Ltd | Professional & scientific | 2012 |
| BIZ Management Ltd | Real estate | 2021 |
| BJM Brothers Ltd | Real estate | 2024 |
| BJR Trading Limited | Transport & logistics | 2022 |
| BL Bespoke Building Ltd | Construction | 2020 |
| Black Arrow Properties Ltd | Real estate | 2020 |
| Black PUG Change Solutions Ltd | Professional & scientific | 2021 |
| Black Square Ventures Ltd | Professional & scientific | 2015 |
| Black Stone Capital Ltd | Construction | 2023 |
| Blackcube 313 Ltd | Transport & logistics | 2018 |
| Blackcurrent Limited | Information & communication | 2001 |
| Blackrock Traders Ltd | Wholesale & retail | 2022 |
| Blissful Legacy Ltd | Real estate | 2023 |
| Blisszen Ltd | Wholesale & retail | 2025 |
| Blitz Line Ltd | Construction | 2025 |
| Blue Burner Sutton Ltd | Construction | 2021 |
| Blue Shine International Equipment Rental Ltd | Wholesale & retail | 2025 |
| Blue Windows Medical Equipment UK Limited | Wholesale & retail | 2024 |
| Blueberries Business Services Ltd | Professional & scientific | 2009 |
| Bluebridge Technology Ltd | Wholesale & retail | 2026 |
| Blueprint Ready Real Estate Limited | Construction | 2026 |