| Bidco Koru Limited | Other services | 2020 |
| Bideford Retail Ltd | Wholesale & retail | 2023 |
| Bids and Bloom Ltd | Information & communication | 2024 |
| Bidspark Limited | Professional & scientific | 2025 |
| Bidston Moss Car Wash Ltd | Other services | 2019 |
| Bidzness Ltd | Wholesale & retail | 2026 |
| BIF Opportunities Limited Partnership | | 2021 |
| Bifrost Cloud Limited | Information & communication | 2025 |
| Big & Luna International Trading Ltd | Extraterritorial | 2023 |
| Big & Tall Ltd | Wholesale & retail | 2025 |
| Big Accounting Services Ltd | Professional & scientific | 2023 |
| Big Amateur Telescope Limited | Information & communication | 2014 |
| Big B Ltd | Wholesale & retail | 2025 |
| Big BAD Investments Ltd | Hospitality | 2023 |
| Big BAD Wolf Properties Ltd | Households | 2020 |
| Big BAG Technique Limited | Professional & scientific | 2006 |
| Big Bargains Depot Limited | Wholesale & retail | 2021 |
| Big Bazar Ltd | Wholesale & retail | 2025 |
| Big Bear Little Bear Limited | Professional & scientific | 2017 |
| Big Bear Store Limited | Wholesale & retail | 2016 |
| Big BEE Events Limited | Arts & recreation | 2021 |
| Big BEN Investments Ltd | Real estate | 2019 |
| Big BEN Properties Ltd | Real estate | 2021 |
| Big BEN Tobacco Company Limited | Administrative & support | 1988 |
| Big Big International Trading Ltd | Extraterritorial | 2023 |
| Big Bird Poultry Ltd | Wholesale & retail | 2023 |
| Big Bite (UK) Ltd | Hospitality | 2012 |
| Big Bites Adil & Co Ltd | Hospitality | 2019 |
| Big Blue Projects Ltd | Information & communication | 2021 |
| Big Bold Leap Consulting Limited | Professional & scientific | 2023 |
| Big Boss Properties Ltd | Real estate | 2020 |
| Big Box Art Limited | Wholesale & retail | 2018 |
| Big BOY Toys Ltd | Wholesale & retail | 2024 |
| Big Brand Ideas Limited | Information & communication | 2011 |
| Big Brand Sourcing Limited | Professional & scientific | 2013 |
| Big Brother Food Ltd | Hospitality | 2024 |
| Big Bucks Limited | Other services | 2021 |
| Big Caterer Cuisine Ltd | Hospitality | 2025 |
| Big Cloud Recruitment Ltd | Administrative & support | 2013 |
| Big Comedy Shop UK Limited | Education | 2025 |
| Big Content Media Ltd | Other services | 2018 |
| Big Crane Trading Limited | Wholesale & retail | 2019 |
| Big Discount Bargain Store Gorton Ltd | Wholesale & retail | 2022 |
| Big Discount Convenience Store Ltd | Wholesale & retail | 2017 |
| Big Drag Events Ltd | Arts & recreation | 2024 |
| Big Earth Ltd | Information & communication | 1997 |
| Big Easy Investment Company | Real estate | 2019 |
| Big Easy Limited | Administrative & support | 2000 |
| Big Easy Trustees Limited | Administrative & support | 2023 |
| Big Evil Corporation Ltd | Information & communication | 2017 |
| Big FAT Jenna Ltd | Arts & recreation | 2024 |
| Big Fish Devco (Soapsud) Ltd | Construction | 2021 |
| Big Fish Holdings 1 Ltd | Financial services | 2021 |
| Big Fish Rentals Limited | Administrative & support | 2006 |
| Big Fish Transport Limited | Transport & logistics | 2024 |
| Big Flower Stall Ltd | Wholesale & retail | 2026 |
| Big Growth Group Ltd | Information & communication | 2025 |
| Big Guns Media Ltd | Professional & scientific | 2016 |
| Big Hornns Limited | Arts & recreation | 2018 |
| Big Human Energy Ltd | Professional & scientific | 2026 |
| Big Idea Brand Marketing Limited | Professional & scientific | 2010 |
| Big in Wind Ltd | Construction | 2024 |
| Big Issue North Trust Ltd | Health & social care | 1996 |
| Big Jim’S Ltd | Wholesale & retail | 2023 |
| Big JOE Transport Ltd | Transport & logistics | 2025 |
| Big Life Schools | Education | 2012 |
| Big Life Services Limited | Health & social care | 1997 |
| Big Little Brands PTY Ltd | Wholesale & retail | 2026 |
| Big Mamma Fast Foods Ltd | Hospitality | 2025 |
| Big Mamma Shakes Ltd | Hospitality | 2025 |
| Big Mommas Waffles Ltd | Manufacturing | 2015 |
| Big Moon Limited | Extraterritorial | 2021 |
| Big MRJ Estates Ltd | Real estate | 2015 |
| Big Muscle Limited | Arts & recreation | 2025 |
| Big NOO Ltd | Professional & scientific | 2024 |
| Big North Star Ltd | Wholesale & retail | 2025 |
| Big Parrot Ltd | Hospitality | 2023 |
| Big People Community CIC | Education | 2014 |
| Big Picture Visuals Ltd | Information & communication | 2022 |
| Big Pixel Media Ltd | Administrative & support | 2022 |
| Big Red Fphp Limited | Construction | 2020 |
| Big Red Industries (Huddersfield) Ltd | Construction | 2018 |
| Big Red PC Limited | Construction | 2020 |
| Big Red Properties Ltd | Real estate | 2024 |
| Big Red Rentals Ltd | Real estate | 2024 |
| Big Revolution Ltd | Information & communication | 2010 |
| Big River Services UK Limited | Other services | 2016 |
| Big Saver Limited | Wholesale & retail | 2004 |
| Big Seans Lighting & Props Limited | Information & communication | 2022 |
| Big Shine Car Wash Ltd | Administrative & support | 2023 |
| Big Shot Pizza Ltd | Hospitality | 2025 |
| Big SLO Limo Company Limited | Transport & logistics | 2006 |
| Big Soul Productions CIC | Arts & recreation | 2024 |
| Big Stone Technology Group Ltd | Wholesale & retail | 2025 |
| Big Three Projects Ltd | Households | 2025 |
| Big Tray BBQ Ltd | Hospitality | 2025 |
| Big UP TV Limited | Information & communication | 2017 |
| Big Wave Global Ltd | Other services | 2023 |
| Big WOW Events Ltd | Arts & recreation | 2017 |
| Big&Bold Trends UK Ltd | Wholesale & retail | 2025 |