| Ascg Ltd | Real estate | 2018 |
| Assist Accounting & Business Support Ltd | Professional & scientific | 2019 |
| Astra Associates Limited | Professional & scientific | 2015 |
| Astro Designs Ltd. | Professional & scientific | 2012 |
| Aubergine Advantage Ltd | Information & communication | 2008 |
| Audio Vids Limited | Information & communication | 2013 |
| Automotive Insight Global Ltd | Professional & scientific | 2025 |
| Autotech Marlborough Limited | Wholesale & retail | 2017 |
| Autymation Ltd | Manufacturing | 2023 |
| Avatar Graphic Design and Signmaking Limited | Arts & recreation | 1990 |
| Avena Strategy Ltd | Professional & scientific | 2026 |
| Avendia Ltd | Construction | 2020 |
| Avenue Design & Build Wiltshire Limited | Construction | 2021 |
| Aviation Training Support Ltd | Transport & logistics | 2010 |
| Axcelium Ltd | Information & communication | 2024 |
| Axford Garage Services Limited | Wholesale & retail | 2009 |
| Azevedo Microsoft Consulting Ltd | Information & communication | 2021 |
| B & C Brickwork Limited | Construction | 2013 |
| B D C Systems Limited | Wholesale & retail | 1994 |
| B2 Plumbing & Bathrooms Limited | Construction | 2022 |
| Babble and Goose Limited | Wholesale & retail | 2020 |
| Badalona Holdings Limited | Professional & scientific | 2015 |
| Bailey Energy Services Limited | Construction | 2020 |
| Balston Holdings LLP | | 2017 |
| Balston Property Holdings Limited | Real estate | 2019 |
| Barbury Castle Estate LLP | | 2016 |
| Bardwell Homes and Investments Ltd | Real estate | 2023 |
| Barn Street Management Limited | Real estate | 1987 |
| Barnard Investment Company,Limited | Real estate | 1934 |
| Barrs Yard Wine Company Limited | Wholesale & retail | 2017 |
| Barstow Bradstock Associates LLP | | 2020 |
| Barworth Medical (UK) Limited | Wholesale & retail | 1998 |
| Base Shapes Ltd | Manufacturing | 2026 |
| Bath Road Limited | Construction | 2016 |
| Baudelaire Clinic Limited | Real estate | 2021 |
| Baudelaire Medical Ltd | Other services | 2022 |
| BDI Property Search Limited | Real estate | 2005 |
| Beagle Research Ltd | Administrative & support | 2004 |
| Beale Radiology Ltd | Health & social care | 2018 |
| Beavis Carpentry Contractors Ltd | Construction | 2007 |
| Beavis Holdings Limited | Extraterritorial | 2024 |
| Beckal Limited | Professional & scientific | 2023 |
| Bedwyn Three Tuns Limited | Hospitality | 2022 |
| Beechmast Consultancy Limited | Professional & scientific | 2009 |
| Beeline Properties Limited | Real estate | 1998 |
| Beers and Cheers Ltd | Hospitality | 2025 |
| BEN Wills Hair & Beauty Ltd | Other services | 2021 |
| Bench and Barrel Studios Limited | Wholesale & retail | 2025 |
| Bengame Limited | Wholesale & retail | 2022 |
| Berisha Trading Ltd | Wholesale & retail | 2020 |
| Berkshire Concrete Limited | Manufacturing | 2017 |
| Berkshire Jobs Limited | Administrative & support | 2004 |
| Bettyhill 2 Wind Ltd | Administrative & support | 2018 |
| BEW & Co Limited | Professional & scientific | 2002 |
| Beynon TP Holdings Ltd | Financial services | 2025 |
| Bhajis Catering Limited | Hospitality | 2023 |
| Bioquest Limited | Professional & scientific | 2011 |
| Bioseed Ltd | Administrative & support | 2026 |
| Bizarre Ltd | Wholesale & retail | 2018 |
| Biztech Enterprise Limited | Professional & scientific | 2010 |
| BL Design Studio Ltd | Professional & scientific | 2023 |
| Black Barn Automotive Limited | Wholesale & retail | 2017 |
| Blacknall Limited | Professional & scientific | 2006 |
| Blake House Apartments Limited | Real estate | 2009 |
| Blay Ventilation Ltd | Construction | 2020 |
| Blossom Wellness & Pilates Limited | Other services | 2025 |
| BLS Building Specialists Ltd | Construction | 2006 |
| Blue Penguin Television Limited | Extraterritorial | 2016 |
| Blue Whale Systems Ltd | Professional & scientific | 2005 |
| Blundy Building Services Limited | Construction | 2006 |
| BM Trustees Limited | Financial services | 2006 |
| Boardroom Review Limited | Professional & scientific | 2012 |
| Boast Project Management Limited | Construction | 2018 |
| Boathouse Cafe Portscatho Limited | Hospitality | 2025 |
| Boho Betty UK Limited | Wholesale & retail | 2012 |
| Bolstridge Estates Limited | Real estate | 2007 |
| Booko Ltd | Information & communication | 2025 |
| Borrowmi Ltd | Administrative & support | 2017 |
| Bosacki Travel Management Ltd | Administrative & support | 2015 |
| Bpdo Ltd | Professional & scientific | 2013 |
| Bpe(Uk) Ltd | Professional & scientific | 2019 |
| BR Marlborough Property Ltd | Real estate | 2016 |
| Brackenbury Home Ltd | Manufacturing | 2018 |
| Bradstock Commercial Finance Limited | Financial services | 2019 |
| Bravis Contracting Limited | Extraterritorial | 2020 |
| Brewis Limited | Real estate | 2018 |
| Brian Meehan Ltd. | Arts & recreation | 2000 |
| Bricoflor Ltd | Wholesale & retail | 2012 |
| Bridge Street (Manton) Management Company Limited | Households | 2002 |
| Bridgewell Holdings Limited | Professional & scientific | 1989 |
| Brimstone Consultancy Services Ltd | Information & communication | 1997 |
| Bristol IMP Limited | Real estate | 2021 |
| Brooks Campbell Limited | Professional & scientific | 2014 |
| Brookwall Limited | Extraterritorial | 2012 |
| Brouha Marketing Limited | Professional & scientific | 2006 |
| Browne GAS and Heating Ltd | Construction | 2022 |
| Bruce Mayhew Limited | Arts & recreation | 2019 |
| Bryan Read Limited | Agriculture & fishing | 1990 |
| Bucklefields Business Developments Limited | Professional & scientific | 2001 |
| Bullfinch Media Ltd | Information & communication | 2012 |