| Blue Marina Ltd | Wholesale & retail | 2025 |
| Blue Monday Podcast Limited | Information & communication | 2025 |
| Blue Moon Introductions Limited | Other services | 2019 |
| Blue Novation Ltd | Information & communication | 1999 |
| Blue Oak Accountancy Limited | Information & communication | 2025 |
| Blue Oak Retail Ltd | Wholesale & retail | 2025 |
| Blue Ocean Investment Co Ltd | Financial services | 1999 |
| Blue Partners Logistics UK Limited | Transport & logistics | 2024 |
| Blue Raven Property Limited | Construction | 2016 |
| Blue Remnant Enterprises Limited | Professional & scientific | 2024 |
| Blue Rock Project Solutions Ltd | Construction | 2020 |
| Blue Sea Fish Ltd | Hospitality | 2025 |
| Blue Skies ATM Consulting Ltd | Transport & logistics | 2019 |
| Blue Sky Cabs Ltd | Transport & logistics | 2025 |
| Blue Sky Works Limited | Professional & scientific | 2003 |
| Blue Suede Cruise Limited | Administrative & support | 2026 |
| Blue Vector Holdings Ltd | Real estate | 2020 |
| Bluebell Mortgages Ltd | Financial services | 2015 |
| Bluecrest Commerce Ltd | Wholesale & retail | 2026 |
| Bluecron Limited | Wholesale & retail | 2023 |
| Bluefish Technologies Limited | Information & communication | 2019 |
| Blueprint Web Ltd | Information & communication | 2026 |
| Bluescape Energy Limited | Administrative & support | 2022 |
| Bluescape Properties Ltd | Real estate | 2020 |
| Bluestem LLP | | 2017 |
| Bluestone Hotels Ltd | Hospitality | 2024 |
| Bluetrans Services Ltd | Transport & logistics | 2015 |
| Bluewall Property Ltd | Real estate | 2025 |
| Blvck FOX Ltd | Wholesale & retail | 2023 |
| Blyth Technologies Ltd | Information & communication | 2025 |
| Blyth Vale (Halesworth) Management Company Limited | Households | 2019 |
| BM Assets Ltd | Real estate | 2018 |
| BM Healthcare Limited | Health & social care | 2021 |
| BM Parts Ltd | Wholesale & retail | 2025 |
| Bmbmotors Transport Ltd | Wholesale & retail | 2021 |
| BMD Food Ltd | Hospitality | 2026 |
| BME Suffolk Support Group(Bssg) CIC | Health & social care | 2021 |
| BMJ Business Solutions Limited | Information & communication | 2010 |
| Bmph Ltd | Construction | 2026 |
| BMS (East Anglia) Limited | Construction | 2005 |
| BN Contractors & Mom's Dishes Ltd | Hospitality | 2014 |
| BN Media Limited | Administrative & support | 2014 |
| BNA Express Ltd | Transport & logistics | 2026 |
| BNB Live LLP | | 2019 |
| Bnlouis Limited | Wholesale & retail | 2024 |
| BNS Property Management Ltd | Real estate | 2016 |
| Boardelyx Internal Workspace Ltd | Information & communication | 2026 |
| Boardley and Roberts Limited | Manufacturing | 1975 |
| Boardley Group Limited | Financial services | 2025 |
| Boardwalk Consulting Ltd | Information & communication | 2023 |
| Boardwalk Ventures Ltd | Financial services | 2023 |
| Boars Head Investments Ltd | Administrative & support | 2023 |
| Boat Gear Direct Limited | Professional & scientific | 2003 |
| Boat-Shift Marine Transport Limited | Transport & logistics | 2010 |
| BOB & Mouse Ltd | Manufacturing | 2022 |
| BOB Kindred Heritage Consultants Limited | Professional & scientific | 2012 |
| BOB Noakes Engineers Limited | Construction | 2015 |
| Bobby 2026 Ltd | Transport & logistics | 2026 |
| Bobby John Lewis Ltd | Information & communication | 2023 |
| Bobby ZYO Ltd | Transport & logistics | 2013 |
| BOD Trans Ltd | Transport & logistics | 2019 |
| Boda Sports Ltd | Wholesale & retail | 2026 |
| Boddington Property Ltd | Real estate | 2023 |
| Bodecia Roof Windows Ltd | Construction | 2020 |
| Bodiedbyvira Ltd | Wholesale & retail | 2020 |
| Bodrum Kebab House Limited | Hospitality | 2025 |
| Bodywise Health & Performance Ltd | Other services | 2017 |
| Bodywise Property Ltd | Real estate | 2025 |
| Bodzio Transport Ltd | Transport & logistics | 2015 |
| Bogdan Chirieac Ltd | Health & social care | 2023 |
| Bogdan P Trans Limited | Wholesale & retail | 2019 |
| Bohannan Holdings Ltd | Financial services | 2018 |
| Bohemian Bites Catering Ltd | Hospitality | 2025 |
| Bojilovi 85 Ltd | Transport & logistics | 2019 |
| Bolat Properties Ltd | Real estate | 2023 |
| Bolenda Engineering Limited | Manufacturing | 2003 |
| Bolodisgroup Ltd | Professional & scientific | 2024 |
| Bolt Production International Limited | Wholesale & retail | 2024 |
| BOLT147 Ltd | Hospitality | 2025 |
| Boltby Bash Enduro Limited | Arts & recreation | 2015 |
| Bolton Brothers Limited | Water & waste | 1999 |
| Bolton Waste Disposal Limited | Professional & scientific | 2005 |
| Boltons Recycling Limited | Water & waste | 2011 |
| Bomoko Development Properties Ltd | Construction | 2025 |
| Bomoko Properties Ltd | Financial services | 2023 |
| Bon-Shell Limited | Professional & scientific | 2010 |
| Bona Produce Ltd | Wholesale & retail | 2021 |
| Bonbon Choc Ltd | Wholesale & retail | 2019 |
| Bond Digital Ltd | Professional & scientific | 2025 |
| Bonds Landco Ltd | Construction | 2024 |
| Bone and Joint Limited | Health & social care | 2023 |
| Bones Q Ltd | Hospitality | 2018 |
| Bonfield Brothers Limited | Construction | 2015 |
| Bonnie's Estates Ltd | Real estate | 2025 |
| Book Medical Limited | Other services | 2018 |
| Bookingflow Ltd | Professional & scientific | 2024 |
| Bookkeeping by Rachel Ltd | Professional & scientific | 2025 |
| Bookotrip UK PVT Ltd | Administrative & support | 2022 |
| Books NOW Limited | Wholesale & retail | 2015 |
| Boons on Plate Ltd | Manufacturing | 2024 |