| Baraka Investment Ltd | Real estate | 2023 |
| Barana Product Ltd | Wholesale & retail | 2023 |
| Barao Motorcycles Limited | Wholesale & retail | 2022 |
| Barbauld Ltd | Real estate | 2025 |
| Barbican Orthodontist Limited | Financial services | 2026 |
| Barbot Close Management Company Limited | Households | 1992 |
| Barclay Grange Limited | Construction | 2026 |
| Bardam Ltd | Construction | 2024 |
| Bardsley Investments Limited | Real estate | 2023 |
| Barfoot Maintenance Limited | Construction | 2022 |
| Bargain Cars 4 YOU Ltd | Wholesale & retail | 2021 |
| Bargain Household Ltd | Wholesale & retail | 2021 |
| Barkatech Ltd | Information & communication | 2023 |
| Barkley Construction London Limited | Construction | 2018 |
| Barnet Youth Zone | Other services | 2016 |
| Barnett Deli Express Ltd | Wholesale & retail | 2023 |
| Barras Heath Service Station Limited | Wholesale & retail | 2005 |
| Barrington Jewellers Limited | Wholesale & retail | 1999 |
| Barsha's Kitchen Limited | Hospitality | 2020 |
| Barton Ventures Limited | Real estate | 2013 |
| BAS & BAS Ltd | Construction | 2022 |
| Base 60 Technology Limited | Professional & scientific | 2026 |
| Basebex Limited | Information & communication | 2019 |
| Basingstoke Colorectal and Peritoneal Partners LLP | | 2026 |
| Basingstoke Colorectal Partners LLP | | 2023 |
| Baskerville Court Management Company (Neasden) Limited | Households | 1997 |
| Bateleur Partners Limited | Professional & scientific | 2018 |
| Bath Process Consultants Limited | Professional & scientific | 2014 |
| Bath ST Hotel Limited | Hospitality | 1991 |
| Battersea Protect Limited | Administrative & support | 2023 |
| Battle Road Fish Bar Limited | Hospitality | 2024 |
| Bautista Care Limited | Health & social care | 2023 |
| Bavisha Consultancy Ltd | Professional & scientific | 2022 |
| Baxter Propco Limited | Construction | 2025 |
| Bay Leuw LLP | | 2020 |
| Baybasin Property Maintenance Services Ltd | Other services | 2026 |
| Bayside Building Consultancy Limited | Professional & scientific | 2020 |
| Baysmill Limited | Real estate | 2008 |
| Bazenga Limited | Professional & scientific | 2019 |
| BBQ House Colchester Ltd | Hospitality | 2024 |
| BC Childcare Ltd | Health & social care | 2018 |
| BC Finance & Advisory Limited | Professional & scientific | 2026 |
| BCD Ltd | Construction | 2024 |
| BCL Electrical Ltd | Construction | 2024 |
| BCM Construct Ltd | Construction | 2017 |
| Bctw Services Limited | Administrative & support | 2022 |
| Bctw Services SUB Limited | Real estate | 2025 |
| BCW Build Ltd | Construction | 2025 |
| BE Wise Sisters Ltd | Administrative & support | 2019 |
| Be-Games Limited | Information & communication | 2021 |
| Be-Hookd Ltd | Professional & scientific | 2014 |
| Beacon Props Ltd | Real estate | 2019 |
| BEAD4BEAD Ltd | Wholesale & retail | 2025 |
| Beakay Limited | Wholesale & retail | 2012 |
| Bealaiste Group Ltd | Real estate | 2020 |
| Beam and Craft Limited | Real estate | 2024 |
| Bear Consulting (UK) Ltd | Administrative & support | 2003 |
| Bearings Ltd | Wholesale & retail | 2020 |
| Beatty Estates Ltd | Real estate | 2017 |
| Beatty Management Ltd | Real estate | 2019 |
| Beaumont House (Cole Green) Management Company Limited | Real estate | 2000 |
| Beaumont Street Properties Ltd | Real estate | 2023 |
| Beaumonte Ltd | Wholesale & retail | 2026 |
| Beauty & Wholeness Bar Ltd | Other services | 2021 |
| Beauty Academy at the London College (UK) Ltd | Education | 2020 |
| Beauty Bees Limited | Other services | 2024 |
| Beauty by Stef Ltd | Other services | 2024 |
| Beauvoir Ltd | Real estate | 2024 |
| Bebella Ltd | Wholesale & retail | 2022 |
| Beceau Mxli Limited | Wholesale & retail | 2025 |
| Beckeng Limited | Professional & scientific | 2022 |
| Beckholm Limited | Professional & scientific | 2025 |
| Beda Eagle Limited | Real estate | 2021 |
| Beda Horton Limited | Real estate | 2021 |
| Bedidi Limited | Hospitality | 2016 |
| BEE Sports Consultancy Ltd | Professional & scientific | 2022 |
| Beechwood Avenue (Ruislip) Limited | Real estate | 1996 |
| Beechwood Deliveries Limited | Transport & logistics | 2025 |
| Beeha Limited | Wholesale & retail | 2023 |
| Being Humanitarian Ltd | Health & social care | 2013 |
| Beis Chinuch Primary School Limited | Education | 2007 |
| Beisa Holdings Limited | Financial services | 2021 |
| Bejta Bajda Limited | Professional & scientific | 2026 |
| Belgrave Property Developers Ltd | Real estate | 2022 |
| Bell Index Limited | Hospitality | 1981 |
| Bellaisa Ltd | Wholesale & retail | 2024 |
| Bellalou Investment Ltd | Real estate | 2024 |
| Bellevie Properties Ltd | Real estate | 2021 |
| Bellhouse Capital Ltd | Financial services | 2010 |
| Belljoy Limited | Real estate | 1998 |
| Bellstrong Construction Ltd | Construction | 1998 |
| Bellview Consultancy Services Ltd | Professional & scientific | 2015 |
| Bellvue Limited | Construction | 2002 |
| Belmore Energy Ltd | Professional & scientific | 2005 |
| Belton 2 Limited | Real estate | 2017 |
| Belvia Victoria Ltd | Wholesale & retail | 2026 |
| Belview Golf Limited | Arts & recreation | 2013 |
| Bemar Freight and Logistics Ltd | Transport & logistics | 2025 |
| Bemar Transport Ltd | Transport & logistics | 2026 |
| Bemj Concierge Services Ltd | Administrative & support | 2025 |