| Bebe Sucre Ltd | Information & communication | 2023 |
| Bedrock Books CIC | Health & social care | 2020 |
| BEE Brook Ltd | Administrative & support | 2014 |
| Beechwood (Block a) Management Company Limited | Households | 1990 |
| Beechwood Close Ltd | Professional & scientific | 2024 |
| Beeston Brothers Limited | Wholesale & retail | 2004 |
| Belbie Civil Engineering Ltd | Construction | 2025 |
| Belchamp Consulting Services Limited | Information & communication | 2003 |
| Belchamp Wrap Around Care Limited | Health & social care | 2025 |
| Belfora Limited | Wholesale & retail | 2026 |
| Bell Landscapes Ltd | Administrative & support | 2013 |
| Bella Rosa Ipswich Limited | Health & social care | 2025 |
| Bellview Carpentry Limited | Construction | 2004 |
| Bespoke Blast Doors Ltd | Professional & scientific | 2024 |
| Bespoke Blinds (Long Melford) Ltd | Wholesale & retail | 2017 |
| Bespoke Property Solutions Suffolk Ltd | Construction | 2022 |
| Bespoke Software Development Limited | Information & communication | 2011 |
| Bespoke Wood Flooring Specialists Limited | Construction | 2024 |
| Best Home Property Services LLP | | 2026 |
| Bestevenn Limited | Agriculture & fishing | 2020 |
| BEX Harvey Limited | Information & communication | 2012 |
| BG Packaging Limited | Administrative & support | 2002 |
| Big Clean Little Clean Limited | Administrative & support | 2003 |
| Big Sky Holdings Ltd | Financial services | 2025 |
| Big Tattoo Events Limited | Information & communication | 2017 |
| Big Tune Club Limited | Information & communication | 2020 |
| Bigger Boat Consulting Limited | Administrative & support | 2017 |
| Billhamcutts Ltd | Real estate | 2016 |
| Biodiversity Total Solutions Limited | Construction | 2025 |
| Bipolar Peer Project CIC | Health & social care | 2025 |
| Birch Court Residents Association Limited | Households | 1988 |
| Birch Leisure and Entertainment Limited | Administrative & support | 2023 |
| Birchall Steel Limited | Real estate | 2013 |
| Birdie and Bangs Sudbury LLP | | 2021 |
| Bishop's Coffee Company Ltd | Hospitality | 2020 |
| Bishopsgate (Burton Street, Wakefield) Management Company Limited | Households | 2002 |
| Black Pheasant Consulting Limited | Professional & scientific | 2025 |
| Blackbourne Developments Ltd | Construction | 2008 |
| Blackfish Consultancy Ltd | Professional & scientific | 2024 |
| Blackhall Mill (Management 2011) Limited | Households | 2011 |
| Blacklands Hall Barns Management Company Limited | Real estate | 2004 |
| Blackthorn Landscapes Limited | Administrative & support | 2020 |
| Blanche Investments Ltd | Real estate | 2025 |
| Blendbox Coffee Limited | Wholesale & retail | 2025 |
| Blooming Confident Ltd | Wholesale & retail | 2025 |
| Bloomsbury Mews (2) Management Company Limited | Households | 2008 |
| BLU8 Limited | Professional & scientific | 2021 |
| Blue Chalk Ltd | Manufacturing | 2022 |
| Blue HAT Dog Training Ltd | Other services | 2023 |
| Bluebird Geoscience Marine Limited | Professional & scientific | 2025 |
| BM Heating Limited | Construction | 2020 |
| BMF Taxis Limited | Transport & logistics | 2020 |
| Bmqlandscaping Ltd | Construction | 2024 |
| BMS (EN) Ltd | Construction | 2018 |
| BNX Group Limited | Professional & scientific | 2016 |
| Boars Head Properties Limited | Real estate | 2005 |
| Bobak Conservation Limited | Other services | 2012 |
| Bobon Limited | Professional & scientific | 2025 |
| BOH Carpentry Ltd | Construction | 2021 |
| Bondfam Ltd | Financial services | 2023 |
| Boostbit Limited | Administrative & support | 2024 |
| Border Property Limited | Real estate | 2021 |
| Border Roofing (Sudbury) Limited | Construction | 2006 |
| Bored Parent Ltd | Wholesale & retail | 2025 |
| Bosco International Trading Limited | Wholesale & retail | 2015 |
| Bossa SPV 1 Limited | Information & communication | 2022 |
| Bossa Studios Limited | Information & communication | 2010 |
| Bossaco Limited | Information & communication | 2011 |
| Boudica Will Services Ltd | Professional & scientific | 2024 |
| Bovill & Boyd (Technical Mouldings) Limited | Manufacturing | 2009 |
| Bower Court Management Company Limited | Households | 1982 |
| Boxford Sunflowers Childcare C.I.C. | Education | 2015 |
| Boxstore (Suffolk) LLP | | 2006 |
| Boyton Project Management Limited | Professional & scientific | 2022 |
| Boyton Property Group Ltd | Construction | 2025 |
| BP Roro Limited | Transport & logistics | 2012 |
| Brae Court RTM Company Limited | Real estate | 2004 |
| Braider Limited | Professional & scientific | 2022 |
| Bramley House (HM04 Aylesbury) Management Company Limited | Households | 2018 |
| Branwhite Farms Limited | Agriculture & fishing | 1960 |
| Braybrooke Mews Management Limited | Real estate | 2008 |
| Breach Manor Farms Limited | Agriculture & fishing | 2003 |
| Breakout for Business Ltd | Administrative & support | 2016 |
| Breebuck LLP | | 2023 |
| Brent Mill Drive Limited | Households | 2017 |
| Brenvale Limited | Administrative & support | 2006 |
| Brett Vale Thatchers Ltd | Construction | 2015 |
| Bri-Chez Haulage Limited | Financial services | 2020 |
| Briarcare Ltd | Administrative & support | 2014 |
| Briarcare Recruitment Agency Holdings Limited | Health & social care | 2018 |
| Brideside Boutique Limited | Wholesale & retail | 2023 |
| Bridge Cottage Farm Business Limited | Agriculture & fishing | 2018 |
| Bridgehill Property Solutions Limited | Real estate | 2025 |
| Bridgeshadow Limited | Professional & scientific | 1986 |
| Bridlington Apartments Ltd | Households | 2010 |
| Bright & Beautiful Garden Maintenance Limited | Administrative & support | 2014 |
| Bright Heights Management Company Limited | Households | 2020 |
| Bright Smile Hygiene Clinic Limited | Health & social care | 2014 |
| Brighton Road (Redhill) Management Co. Limited | Households | 2003 |
| Brinkwood Limited | Arts & recreation | 2013 |