| Best Auto Services Ltd | Wholesale & retail | 2025 |
| Best Home Surrey Ltd | Construction | 2024 |
| Best Homes (UK) Ltd | Real estate | 2013 |
| Best Homes Developers Ltd | Construction | 2018 |
| Best Homes Properties Limited | Real estate | 2014 |
| Best Homes Sussex Ltd | Real estate | 2025 |
| Best Interiors Projects Ltd | Construction | 2023 |
| Best Local Builder Ltd | Construction | 2014 |
| Best Move Limited | Real estate | 2025 |
| Best Spaces Ltd | Real estate | 2023 |
| Bethel CHS Ltd | Hospitality | 2024 |
| Betta Living Ltd | Real estate | 2016 |
| Better View Window and Exterior Cleaning Ltd | Administrative & support | 2021 |
| Beulah Electricals Ltd | Construction | 2017 |
| BEYOURSELF2DAY Ltd | Education | 2017 |
| BF Plant Sales/Hire Ltd | Construction | 2009 |
| Bharti Devina Limited | Wholesale & retail | 2016 |
| Bhatti Movers Ltd | Transport & logistics | 2023 |
| Bhaugeeruthy Consultancy Services Ltd | Health & social care | 2020 |
| BHM Motors Ltd | Wholesale & retail | 2019 |
| Biala Roza Ltd | Wholesale & retail | 2016 |
| Bib's Esfihas Ltd | Manufacturing | 2021 |
| Bibinee Dolls and Friends CIC | Wholesale & retail | 2025 |
| Bible Streams CIC | Other services | 2024 |
| Bidesi Ltd | Administrative & support | 2023 |
| Big C Brickwork Limited | Construction | 2019 |
| Big Hammer PSV Road Engineers UK Ltd | Professional & scientific | 2025 |
| Bigda Ltd | Real estate | 2025 |
| Bijou London Tailoring Ltd | Other services | 2020 |
| Bikebase Limited | Wholesale & retail | 2015 |
| Bikovo Ltd | Construction | 2018 |
| Billdup Limited | Administrative & support | 2022 |
| Billions Global Ltd | Wholesale & retail | 2024 |
| BIM Electrical Ltd | Construction | 2016 |
| BIM Eureka Ltd | Professional & scientific | 2019 |
| BIO Collectors Holdings Limited | Water & waste | 2012 |
| BIO Collectors Limited | Hospitality | 2009 |
| Biophilica Ltd | Manufacturing | 2019 |
| Biosec Intergalactic Limited | Manufacturing | 2024 |
| Biotc UK CIC | Administrative & support | 2025 |
| Birju Properties Ltd | Real estate | 2024 |
| Birthday FM Ltd | Information & communication | 2023 |
| Bismillah Green Ltd | Other services | 2024 |
| Bismillah Superstore Limited | Wholesale & retail | 2015 |
| Bismillah Vibes Ltd | Wholesale & retail | 2025 |
| Bite & Bloom Ltd | Hospitality | 2025 |
| Bitlogix Ltd | Information & communication | 2017 |
| Bitstyle Ltd | Information & communication | 2014 |
| Bitterlies Ltd | Wholesale & retail | 2026 |
| Bizilance Legal Consultants Limited | Professional & scientific | 2026 |
| Black Bulls Driving School Ltd | Education | 2025 |
| Black Forest Investments Ltd | Real estate | 2010 |
| Black Golf Property Ltd | Real estate | 2024 |
| Black Joy Community Interest Company | Education | 2022 |
| Black Sporty Spice Ltd | Wholesale & retail | 2020 |
| Blackoak Ltd | Hospitality | 2016 |
| Blackrock Real Estate Ltd | Construction | 2021 |
| Blankson & Torto Associates Limited | Real estate | 2021 |
| Blanx Media Incorporated Ltd | Wholesale & retail | 2011 |
| Bldn Ltd | Professional & scientific | 2019 |
| Blessed Limited | Professional & scientific | 2000 |
| Blinky Bill Properties Ltd | Real estate | 2023 |
| Bliss Forever Ltd. | Wholesale & retail | 2022 |
| Blitzo Logistics Ltd | Other services | 2024 |
| BLK Property Solutions Ltd | Real estate | 2025 |
| Bloom in Nature Honeyhive Limited | Health & social care | 2024 |
| Bloom Property Management Services Ltd | Real estate | 2026 |
| Blossom & Beauty Ltd | Wholesale & retail | 2025 |
| BLP Electrical Services Ltd | Construction | 2015 |
| BLU 1 Skip Hire Limited | Water & waste | 2015 |
| Blue Grey Norwood Limited | Real estate | 2022 |
| Blue Rose Real Estate Ltd. | Construction | 2016 |
| Blue Storm Solutions Limited | Real estate | 2008 |
| Bluebridge Tech Ltd | Information & communication | 2025 |
| Blueserve Facilities Ltd | Construction | 2010 |
| Bluesmoke LLP | | 2020 |
| Bluestar Commercial Services Ltd | Real estate | 2020 |
| Blufreelancer.Com Limited | Wholesale & retail | 2025 |
| Blurrr Ltd | Other services | 2022 |
| BM Electro Ltd | Manufacturing | 2014 |
| BM Transport Ltd | Transport & logistics | 2021 |
| Bmmk Accountancy Ltd | Professional & scientific | 2013 |
| BN Car Hire Ltd | Administrative & support | 2020 |
| BNC Electrical Services Ltd | Construction | 2025 |
| BNC Landscaping Team Ltd | Administrative & support | 2023 |
| BNW Accountants Limited | Administrative & support | 2012 |
| BNW BPO Services Ltd | Administrative & support | 2017 |
| BNW Electrical & Heating Services Ltd | Construction | 2018 |
| Boadu Properties Ltd | Real estate | 2020 |
| Body Esprit Limited | Health & social care | 2019 |
| Bohdan Builders Ltd | Construction | 2026 |
| Boiler and Heating Solutions Ltd | Construction | 2021 |
| Boiler and Plumbing Repairs 247 Limited | Construction | 2025 |
| Bojidar Ltd | Construction | 2011 |
| Bola Holis Ltd. | Manufacturing | 2013 |
| Bolo Athletics Ltd | Wholesale & retail | 2021 |
| BON Goût Ltd | Manufacturing | 2022 |
| Bond & Co Investments Ltd | Real estate | 2024 |
| Bondzie & Co Ltd | Professional & scientific | 2016 |
| Bonney Cleaners Limited | Administrative & support | 2020 |