| Autoresponze Limited | Professional & scientific | 2020 |
| Auwelt Group Ltd | Wholesale & retail | 2024 |
| AV Stumpfl Ltd | Arts & recreation | 2023 |
| Avaks Medical Ultrasound UK Ltd | Health & social care | 2016 |
| AVALANCHE360 Limited | Information & communication | 2016 |
| Avande Limited | Information & communication | 2024 |
| Avande Storage Limited | Transport & logistics | 2026 |
| Avantgarde Autos Limited | Wholesale & retail | 2013 |
| Avian Landscaping Ltd | Administrative & support | 2024 |
| Aviserv Transport Services Limited | Administrative & support | 2009 |
| Avji Limited | Information & communication | 2016 |
| Avuke Group Limited | Professional & scientific | 2019 |
| Axiomatic Consulting Limited | Professional & scientific | 2021 |
| Aydin 6 Ltd | Administrative & support | 2023 |
| Ayeh Trading Limited | Transport & logistics | 2014 |
| Ayres Consulting Ltd | Professional & scientific | 2016 |
| Aysa Ltd | Wholesale & retail | 2023 |
| Aztoria Homes Ltd | Real estate | 2020 |
| B & P Pharma Limited | Wholesale & retail | 2022 |
| B Kumar Surgery Limited | Health & social care | 2016 |
| B Lion Consulting Ltd | Wholesale & retail | 2023 |
| B R D Services Ltd | Health & social care | 2020 |
| B&C Property Investments Ltd | Real estate | 2018 |
| B&C Property Management & Lettings Ltd | Real estate | 2019 |
| B&Rhomeimprovement Ltd | Construction | 2020 |
| Baby Treasure Ltd | Wholesale & retail | 2024 |
| Bakester Box Ltd | Manufacturing | 2020 |
| Bala Land & Property Ltd | Real estate | 2019 |
| Balaji Ecommerce Ltd | Wholesale & retail | 2025 |
| Balloon One Ltd. | Administrative & support | 2003 |
| Balloon One Solutions Limited | Information & communication | 2016 |
| Ballycommon Limited | Administrative & support | 2012 |
| Ballycommon Plant Limited | Construction | 2020 |
| Ballycommon Rail Limited | Construction | 2016 |
| Ballycommon Services Limited | Construction | 2003 |
| Ballytarsna Construction Limited | Construction | 2008 |
| Banas Enterprises Ltd | Transport & logistics | 2018 |
| Bang Fitness & Performance Ltd | Arts & recreation | 2021 |
| Barakah Global Ltd | Wholesale & retail | 2025 |
| Barnards Capital Limited | Financial services | 2024 |
| Barnards Contracts Limited | Extraterritorial | 1997 |
| Barnards Interiors Limited | Construction | 2024 |
| Barnards' Ceilings and Partitions Limited | Construction | 1994 |
| Barnes Recycling Limited | Water & waste | 2014 |
| Barnet Process Control Systems Limited | Professional & scientific | 2019 |
| Baron Warren Redfern LLP | | 2024 |
| Barton Enterprises Ltd | Construction | 2022 |
| Basafa Limited | Real estate | 2014 |
| Bastin Consulting Limited | Professional & scientific | 2022 |
| Bathroom Retail Group Limited | Financial services | 2012 |
| Bathroomsbydesign Group Ltd | Financial services | 2018 |
| Bathroomsbydesign Retail Ltd | Wholesale & retail | 2007 |
| Bayat Trading Ltd | Wholesale & retail | 2025 |
| BB Painting Ltd | Construction | 2025 |
| BBC Double Glazing Limited | Construction | 2022 |
| BBC Panels Swindon Ltd | Construction | 2025 |
| BBS Additi+On Limited | Wholesale & retail | 2017 |
| BC Remittance Limited | Financial services | 2015 |
| BC Yacht Services Ltd | Manufacturing | 2022 |
| BDS Trans Ltd | Manufacturing | 2026 |
| BE Positive Overseas Ltd | Information & communication | 2023 |
| BE Strong Ltd | Information & communication | 2025 |
| Beau ROI Limited | Information & communication | 2023 |
| Beaumont PR Limited | Professional & scientific | 2026 |
| Bebodyful Ltd | Other services | 2023 |
| Beepr Events Ltd | Hospitality | 2016 |
| Before Creative Ltd | Professional & scientific | 2012 |
| Bella Casa Construction Ltd | Administrative & support | 2017 |
| Bella Creative LAB Ltd | Wholesale & retail | 2022 |
| Bella Equity Ltd | Real estate | 2008 |
| Belle View Homes Limited | Real estate | 2023 |
| Belvedere Properties London Limited | Hospitality | 2021 |
| Benecol Limited | Manufacturing | 2014 |
| Benek Solution Ltd | Construction | 2014 |
| Benison Solvers Limited | Professional & scientific | 2013 |
| Benjamin Shorten Creative Ltd | Information & communication | 2023 |
| Benxer Limited | Professional & scientific | 2025 |
| Benyx Recovery Limited | Transport & logistics | 2026 |
| Berchie & Co - ACG Ltd | Wholesale & retail | 2022 |
| Berti Advice Limited | Professional & scientific | 2023 |
| Bertusje Ltd | Other services | 2019 |
| Bespoke & Beyond Ltd | Wholesale & retail | 2025 |
| Best Intentions Analytics Limited | Financial services | 2025 |
| Besta Jewerly Ltd | Wholesale & retail | 2023 |
| Bestteck Limited | Wholesale & retail | 2022 |
| Better Psychology Ltd | Health & social care | 2021 |
| Beyico Trading Ltd | Wholesale & retail | 2025 |
| Beyond Labels Consulting Ltd | Administrative & support | 2025 |
| Beyond Reality Ltd | Information & communication | 2024 |
| Bfccst Trading Limited | Other services | 2024 |
| Bgmi Limited | Professional & scientific | 2022 |
| Bharat Forge International Limited | Wholesale & retail | 2010 |
| Big Belly Tales Ltd | Manufacturing | 2025 |
| Big on the Scene Ltd | Information & communication | 2015 |
| Bigopia Limited | Financial services | 2026 |
| Bigwig Media Ltd | Information & communication | 2001 |
| Billy Hardy Carpentry Limited | Construction | 2018 |
| BIO Health Ventures Ltd | Professional & scientific | 2025 |
| Bipo Consultancy UK Ltd | Administrative & support | 2021 |
| Birchfin Ltd | Professional & scientific | 2026 |