| AV Lounge Installations Limited | Construction | 2018 |
| AVF Property Investments Ltd | Real estate | 2021 |
| Avian Construction Group Limited | Construction | 2025 |
| Avian Construction London Ltd | Construction | 2018 |
| Azure Financial Solutions Limited | Financial services | 2007 |
| B & B Rentals Limited | Real estate | 2022 |
| B.R.Commercials-Uk Limited | Manufacturing | 2012 |
| B.R.D. Tech Ltd | Professional & scientific | 2022 |
| Babec Ltd | Professional & scientific | 2014 |
| Bahia Marketing Limited | Professional & scientific | 2025 |
| Baker Frank Limited | Construction | 2010 |
| Baker's Sweet Treats Limited | Manufacturing | 2026 |
| Balby Storage Ltd | Real estate | 2021 |
| Ballyeavon Properties Limited | Financial services | 2015 |
| Ballymote Limited | Construction | 2023 |
| Ballymote Site Services Ltd | Construction | 2021 |
| Barbara Smith CBU Limited | Other services | 2018 |
| Barnaby Clark Design Ltd | Professional & scientific | 2022 |
| Barnards LBJ Ltd | Wholesale & retail | 2024 |
| Barnett Welding Services Ltd | Construction | 2024 |
| Bassett Green Management Limited | Households | 1983 |
| Batch #525 Ltd | Information & communication | 2021 |
| BB Antiques Limited | Wholesale & retail | 2021 |
| BCC Services Limited | Transport & logistics | 2016 |
| BE Mechanical Engineering and Construction Ltd | Professional & scientific | 2021 |
| Becketts Court (Chelmsford) Management Company Limited | Households | 2000 |
| Beddington Properties LLP | | 2008 |
| Beech Street Limited | Wholesale & retail | 2022 |
| BEL Polo Limited | Arts & recreation | 2021 |
| Bell & Co Estate Agents Ltd | Real estate | 2012 |
| Bell Street Mortgages Ltd | Financial services | 2024 |
| Bells SA Limited | Real estate | 2021 |
| Bemoney Ltd | Information & communication | 2025 |
| BEN Kimpton Landscapes Ltd | Administrative & support | 2019 |
| Berry Properties Group Ltd | Construction | 2021 |
| Bespoke Extras Ltd | Wholesale & retail | 2024 |
| Big Amigos Limited | Hospitality | 2007 |
| Big Vans Ltd | Wholesale & retail | 2024 |
| Biodome-Systems Ltd | Manufacturing | 2013 |
| Biomed Solutions Limited | Other services | 2010 |
| Birchdale Builders Limited | Construction | 2018 |
| Birchdale Home and Trade Limited | Construction | 2025 |
| Birchdale Homes Ltd | Real estate | 2022 |
| Bishop Investment Group Ltd | Financial services | 2026 |
| Bishops Stortford Building Solutions Limited | Construction | 2010 |
| BJ Minicabs Limited | Transport & logistics | 2002 |
| Black Mulberry Ltd | Real estate | 2021 |
| Blackhall Ltd | Professional & scientific | 2017 |
| Blackstar Corner Limited | Hospitality | 2019 |
| Blackstar Inns Limited | Hospitality | 2019 |
| Blackstar Lane Limited | Hospitality | 2019 |
| Blackstar Road Limited | Hospitality | 2019 |
| Blackstar Taverns Limited | Hospitality | 2019 |
| Blaker Road Flat Management Company Limited | Households | 2002 |
| Blenheim Close Residents Limited | Real estate | 1989 |
| Bliss Convenience Store Ltd | Wholesale & retail | 2021 |
| Blue Light Medical Ltd | Administrative & support | 2021 |
| Bluebell Home Furnishings Ltd | Wholesale & retail | 2018 |
| Bluerock QMS Ltd | Professional & scientific | 2024 |
| Bond Property Company Limited(The) | Households | 1977 |
| Botany Lodge Management Company Limited | Households | 2023 |
| Bourne Interiors Limited | Construction | 2010 |
| Bourne Plastering Limited | Wholesale & retail | 2012 |
| Bowater Finance Limited | Financial services | 2002 |
| Bowater Price Ltd | Financial services | 2000 |
| Boxall Property Ltd | Real estate | 2021 |
| Boyletts Law Ltd | Professional & scientific | 2020 |
| Bozo & Lorraine Limited | Agriculture & fishing | 2025 |
| Bramley Building Services (South East) Limited | Construction | 2017 |
| Brand Culture Limited | Professional & scientific | 2013 |
| Breathing Space Ltd | Professional & scientific | 2014 |
| Breeze Local Ltd | Administrative & support | 2016 |
| Breezy Bird Cleaning Service Ltd | Administrative & support | 2024 |
| Brian Durham Recruitment Services Limited | Administrative & support | 1987 |
| Brian Durham Recruitment Services Permanent Division Ltd | Administrative & support | 2018 |
| Brine House Management Company Limited | Households | 1990 |
| Brinor Investments Limited | Construction | 1960 |
| Brodia Flat Management Company Limited | Households | 1982 |
| Bromford Farm Limited | Agriculture & fishing | 2025 |
| Brook House (Barking) Management Co. Limited | Households | 1972 |
| Brooksbury Limited | Administrative & support | 2023 |
| Brookvine Limited | Other services | 2015 |
| Bruce New Musical Services Limited | Manufacturing | 2018 |
| BSL Building Services Limited | Construction | 2018 |
| BSR Team Limited | Information & communication | 2013 |
| BTG Golf Ltd | Arts & recreation | 2006 |
| Bugslock Limited | Administrative & support | 2009 |
| Buildforce Contractors Limited | Construction | 2024 |
| Burden Filer Accountants Ltd | Professional & scientific | 2021 |
| Butler Buys Ltd | Real estate | 2024 |
| BY Meg.S Aesthetics Ltd | Other services | 2026 |
| C H C Advisory Limited | Professional & scientific | 2016 |
| C I (Risk Management Services) Ltd | Financial services | 2000 |
| C LE MAY Ltd | Professional & scientific | 2019 |
| C.I.Seaman and SON Ltd | Wholesale & retail | 2016 |
| C3 Education Ltd | Information & communication | 2020 |
| Cable Accessories Limited | Extraterritorial | 1996 |
| Cadair Construction Ltd | Construction | 2020 |
| Calcova Investments Limited | Real estate | 2020 |
| Cambridge Printing Solutions (Digital) Ltd | Manufacturing | 2011 |