| AYN Consulting Limited | Information & communication | 2008 |
| Ayten Gasson Limited | Manufacturing | 2008 |
| Ayush Investments Limited | Real estate | 2002 |
| AZ Estates Ltd | Construction | 1995 |
| Azalea Properties Limited | Real estate | 2002 |
| Azkin Accountaxation Limited | Professional & scientific | 1997 |
| Azmat Control Systems Ltd | Professional & scientific | 2006 |
| AZO Supermarket Limited | Wholesale & retail | 2012 |
| Aztec Modelmakers Limited | Professional & scientific | 1997 |
| Azzumur Limited | Information & communication | 2004 |
| B & Daughters Limited | Real estate | 2026 |
| B Best Limited | Wholesale & retail | 2005 |
| B J Proudfoot Construction Limited | Construction | 2005 |
| B T Electrics Limited | Energy | 2007 |
| B&N Refrigeration & Airconditioning Limited | Energy | 2003 |
| B&R Foods Limited | Hospitality | 2021 |
| B-Max Properties Limited | Hospitality | 1998 |
| B. E. Freight Movements (U K) Limited | Transport & logistics | 1998 |
| B.B Management Accountancy Services Limited | Professional & scientific | 2006 |
| B.B. Auto Spares Limited | | 1981 |
| B.B.H.S. Management Limited | Professional & scientific | 1991 |
| B.E. Freight Movements Limited | Transport & logistics | 1995 |
| B.M. Auto's Limited | Wholesale & retail | 1985 |
| B.M. Properties Limited | Construction | 1981 |
| BA Property Developers Ltd | Real estate | 2021 |
| Baba Investments Limited | Real estate | 2003 |
| Bablas Investments Ltd | Real estate | 2024 |
| Baby JOE Music Limited | Information & communication | 1997 |
| Baddiel & Offspring Limited | Other services | 2001 |
| Badger the Tax MAN Limited | Professional & scientific | 2004 |
| Badr Academy Ltd | Education | 2013 |
| Bafa Properties Limited | Construction | 2006 |
| Baileybrook Limited | Wholesale & retail | 1997 |
| Bains Haulage Limited | Transport & logistics | 2005 |
| Bains Training Services Limited | Transport & logistics | 2002 |
| Bajaj Properties Limited | Real estate | 1978 |
| Bakhtar Interpreters Ltd | Other services | 2001 |
| Bal-Net Limited | Information & communication | 2005 |
| Balanced Earth Limited | Wholesale & retail | 2003 |
| Balanced Response Limited | Professional & scientific | 1999 |
| Balanced Vision Limited | Wholesale & retail | 2006 |
| Bamrose Enterprises Limited | Real estate | 1985 |
| Bamrose Properties Limited | Real estate | 2008 |
| Banbury Physiotherapy Ltd | Health & social care | 2006 |
| Bancstreet Capital Partners Ltd | Wholesale & retail | 1995 |
| Bang the Drum Ltd | Information & communication | 2014 |
| Bangor Close Management Limited | Hospitality | 2001 |
| Bankim Patel & Co. Ltd. | Professional & scientific | 2002 |
| Banner and Associates Limited | Professional & scientific | 1993 |
| Banner Properties Limited | Real estate | 2001 |
| Barakat Medical Ltd | Health & social care | 2025 |
| Barans Removals Limited | Transport & logistics | 2002 |
| Barker & Pike Properties Limited | Real estate | 1998 |
| Barnes & Sons (Undertakers) Limited | Other services | 1956 |
| Barnes Limited | Construction | 2005 |
| Barnes OIL Tank Services Limited | Other services | 2005 |
| Baron Investments Limited | Real estate | 2002 |
| Barranka Limited | | 1985 |
| Barry Craig Ltd. | Arts & recreation | 2016 |
| Bastonshop Ltd | Wholesale & retail | 2022 |
| Basville Limited | Administrative & support | 2006 |
| Baswich Ltd | Real estate | 2022 |
| Bathflow Bathrooms Limited | Professional & scientific | 2024 |
| Batik Limited | Extraterritorial | 2002 |
| Batman Dental Practice Limited | Health & social care | 2006 |
| Bauhaus Ltd | Other services | 2009 |
| Bayshill Limited | Information & communication | 2004 |
| BAZ Security and Care Services Ltd | Administrative & support | 2019 |
| BB Professional Services Ltd | Professional & scientific | 2006 |
| Bcdp Limited | Professional & scientific | 2001 |
| BD Digital Services Limited | Information & communication | 2025 |
| Be-A-Pro Limited Partnership | | 2016 |
| Beaconsfield Enterprise Limited | Construction | 2003 |
| Beaconsfield Guest House Limited | Hospitality | 2001 |
| Beard Envy Ltd | Information & communication | 2019 |
| Beaulane Flat 2 Ltd | Real estate | 2022 |
| Beauty Bliss Limited | Administrative & support | 2005 |
| Beavers Food and Wine Ltd | Wholesale & retail | 2018 |
| Bedi-Leblanc Commodity Limited | Wholesale & retail | 1995 |
| Beebright Limited | Arts & recreation | 2002 |
| Beer GAS 2 U Limited | Other services | 2007 |
| Bees Foodservice Ltd | Wholesale & retail | 2023 |
| Beggars Run Limited | Manufacturing | 2012 |
| Beldom's Skip Hire Limited | Water & waste | 2019 |
| Belglay Services Limited | Professional & scientific | 2003 |
| Belglay Solutions Limited | Professional & scientific | 2008 |
| Belgravia Apartments Ltd | Real estate | 2020 |
| Bell Books (Jane Gore) Limited | Manufacturing | 1959 |
| Bellaural Limited | | 1983 |
| Bellford Consultancy Services Limited | Information & communication | 1997 |
| Bellview Court Management Limited | Real estate | 2005 |
| Benford Automatic Company Limited | Other services | 1964 |
| Benn Consultants Limited | Professional & scientific | 2006 |
| Bensujee Ltd | Professional & scientific | 1997 |
| Bentley Law Associates UK Limited | Professional & scientific | 2016 |
| Berkeley Computer Consultants Limited | Real estate | 1984 |
| Berkeley Price Management Resources Limited | Administrative & support | 2000 |
| Berkshire Ores & Chemicals Limited | Wholesale & retail | 1965 |
| Bernalo Limited | Information & communication | 2004 |
| Bernard. Rousseau | | 1998 |