| Blewtoof Ltd | Arts & recreation | 2022 |
| BLG Consultancy Limited | Professional & scientific | 2007 |
| BLJ Distribution Limited | Transport & logistics | 2020 |
| Blomst Bakery Ltd | Manufacturing | 2023 |
| Bloom Management and Properties Limited | Real estate | 2025 |
| Blooming Green Limited | Agriculture & fishing | 2018 |
| Bloomsbury Place Trust RTM Company Limited | Households | 2021 |
| Blossom Cares Limited | Health & social care | 2015 |
| Blossom Healthcare Ltd | Administrative & support | 2020 |
| Blossom Permanent Make-Up & Skin Therapy Clinic Ltd | Other services | 2020 |
| Blossom's Attic Limited | Wholesale & retail | 2019 |
| Blow & Blush Ltd | Other services | 2018 |
| BLS Accountancy Ltd | Professional & scientific | 2021 |
| Blsl Property Limited | Real estate | 2019 |
| BLU Pearl Investments Limited | Wholesale & retail | 2024 |
| BLU ROC Management Ltd | Construction | 2024 |
| Blue Bert Parsonage Limited | Other services | 2016 |
| Blue Bird Hair Lounge Ltd | Other services | 2026 |
| Blue Dragon Plumbing and Heating Limited | Construction | 2015 |
| Blue Genie Entertainment Limited | Arts & recreation | 2013 |
| Blue Lion Transport Ltd | Transport & logistics | 2019 |
| Blue Mountain Commercial Management Ltd | Administrative & support | 2019 |
| Blue Mountain MID Kent Cleaning Limited | Administrative & support | 2022 |
| Blue Mountain Specialist Cleaning Services Ltd | Administrative & support | 2023 |
| Blue Muki Ltd | Hospitality | 2018 |
| Blue Pepper Mortgages Ltd | Financial services | 2020 |
| Blue Precision Technologies Ltd | Information & communication | 2019 |
| Blue Quarter Management Company Limited | Households | 2006 |
| Blue Rhapsody Pools & Spas Limited | Construction | 2010 |
| Blue Scape Pools Limited | Construction | 2024 |
| Blue Skies Wealth Management Ltd | Financial services | 2018 |
| Blue Sky Trade Limited | Wholesale & retail | 2012 |
| Blue Square Resources Ltd | Professional & scientific | 2014 |
| Blue Star Jets UK Limited | Transport & logistics | 2012 |
| Bluebell Management Group Ltd. | Real estate | 2024 |
| Blueberry Residents Association Limited | Households | 1989 |
| Blueprint D&B Ltd | Construction | 2023 |
| Blueveld Group Limited | Wholesale & retail | 2025 |
| Bluevest Capital Partners Limited | Financial services | 2019 |
| Blunova Interiors Ltd | Construction | 2024 |
| Blush & Brew Ltd | Hospitality | 2025 |
| Blush Beauty (Maidstone) Ltd | Other services | 2024 |
| Bluum Limited | Wholesale & retail | 2018 |
| Bluum Realty Limited | Real estate | 2021 |
| BLÉ Couture Cakes Ltd | Manufacturing | 2020 |
| BLÉ Global Ltd | Professional & scientific | 2022 |
| BM Fast Online Ltd | Wholesale & retail | 2025 |
| BM Workforce Ltd | Administrative & support | 2023 |
| BMA Trans Ltd | Transport & logistics | 2016 |
| BMA Transport Ltd | Transport & logistics | 2016 |
| BMC Cabling Solution Ltd | Information & communication | 2025 |
| Bmcdistribution Ltd | Wholesale & retail | 2023 |
| BMJ Real Estates Ltd | Real estate | 2024 |
| BMK Garage Ltd | Wholesale & retail | 2024 |
| Bmlg Ltd | Transport & logistics | 2017 |
| BMS Homes Care Ltd | Hospitality | 2022 |
| BN Consultancy Ltd | Professional & scientific | 2022 |
| BNG Unit Provision Limited | Administrative & support | 2025 |
| Boarley Court Management Company Limited | Households | 1987 |
| Boat and Bean Ltd | Hospitality | 2025 |
| BOB Prowse Gym Limited | Arts & recreation | 2003 |
| Bobbi Healthcare Solutions Ltd | Health & social care | 2025 |
| Bobby Palmer Ltd | Information & communication | 2024 |
| Bobotrans Limited | Transport & logistics | 2014 |
| Bode IT Limited | Information & communication | 2013 |
| Bodi JO Ltd | Professional & scientific | 2024 |
| Bodillo Limited | Information & communication | 2021 |
| Body Bond Online Ltd | Arts & recreation | 2021 |
| Body Bond Retreats Ltd | Other services | 2023 |
| Body Care Osteopathy Limited | Health & social care | 2025 |
| Body Renew Ltd | Wholesale & retail | 2020 |
| Bodymed Limited | Health & social care | 2013 |
| Bodyshop Services (Maidstone) Limited | Other services | 1996 |
| Bogard Investments Limited | Real estate | 2016 |
| Bogdan Freight Ltd | Transport & logistics | 2025 |
| Boglace Limited | Professional & scientific | 2014 |
| Bogmar Care Plus Ltd | Health & social care | 2019 |
| Boiler Rescue Limited | Construction | 2004 |
| Bold Engineering Design Consultants Limited | Professional & scientific | 2017 |
| Boldasset Limited | Wholesale & retail | 2005 |
| Boleyn Groundworks Limited | Administrative & support | 2024 |
| Bolingbroke House Limited | Households | 1982 |
| Boltolok Ltd | Wholesale & retail | 2020 |
| Bolton Avenue Management Company Limited | Households | 2012 |
| Bolton Media Limited | Information & communication | 2025 |
| Bolton Rose Consulting Ltd | Professional & scientific | 2025 |
| Bolyn Trading Ltd | Wholesale & retail | 2024 |
| Bomero Ltd | Wholesale & retail | 2024 |
| Bond Logistics Ltd | Professional & scientific | 2011 |
| Bond Property Group Ltd. | Real estate | 2020 |
| Bond Street Investments (London) Limited | Professional & scientific | 1997 |
| Bond Street Investments Limited | Real estate | 2003 |
| Bonnies Cosy Cafe Ltd | Hospitality | 2025 |
| Bonsai Law Ltd | Professional & scientific | 2022 |
| Bontea Trans Ltd | Transport & logistics | 2022 |
| Bonus Buildings Limited | Construction | 2006 |
| Bookflow AI Ltd | Information & communication | 2025 |
| Boon Aesthetics Limited | Other services | 2021 |
| Bootcamp UK AB Ltd | Arts & recreation | 2022 |
| Bootcampukbexleyheath Ltd | Arts & recreation | 2023 |