| Bidco Jupiter Limited | Royston | 2022 |
| Biddeford Riverwalk Community Master Holdco Limited | London | 2020 |
| Biddenham Care Holdings Limited | Egham | 2018 |
| Biddulph Wealth Management Limited | Cheltenham | 2023 |
| Biddymundoo Limited | London | 2007 |
| Bidfair Limited | London | 2019 |
| Bidfair UK Property Holdings Limited | London | 2019 |
| Bidfresh Holdings Limited | Southport | 2012 |
| Bidme.Com Limited | Buckshaw Village | 2005 |
| Bidnexus Limited | Guildford | 2021 |
| Bidone Limited | Blagdon | 2023 |
| Bids Trading Limited | London | 2015 |
| Bidstar Ventures Ltd | Bolton | 2024 |
| Bidston Holdings Limited | Birkenhead | 2022 |
| Bidswitch Limited | London | 2022 |
| Bidtwo Limited | Blagdon | 2025 |
| Bidvest Services (UK) Limited | London | 2017 |
| Bidvest Services Group (UK) Limited | London | 2017 |
| Bidzilla Limited | Chessington | 2016 |
| Bieases Ltd | London | 2022 |
| Biecco Holdings Ltd | Reading | 2026 |
| Biedex Capital Markets Limited | London | 2024 |
| Biel Holdings Limited | London | 2020 |
| Bieldside Limited | Aberdeen | 2025 |
| Bielsa 2019/20 Limited | Harrogate | 2025 |
| BIF IV Europe Holdings Limited | London | 2020 |
| BIF IV UK Holdings Limited | London | 2019 |
| Bifa Holdings (UK) Ltd | Bristol | 2026 |
| Bifegs Holdings Ltd | Wilmslow | 2025 |
| Biffa Bidco Limited | High Wycombe | 2022 |
| Biffa Holdco Limited | High Wycombe | 2022 |
| Biffa Limited | High Wycombe | 2016 |
| Biffa Midco Limited | High Wycombe | 2022 |
| Biffa Treatment Services Holdings Limited | High Wycombe | 2024 |
| Bifinity UK Holdco Limited | London | 2022 |
| Bifm UK Buyer Limited | London | 2019 |
| Bifm UK Holdings Limited | London | 2019 |
| Bifm UK Intermediate Limited | London | 2019 |
| Bifm UK SUB Limited | London | 2019 |
| Bifrost Holdings Ltd | Southend-On-Sea | 2023 |
| Bifrost Studios UK Ltd | London | 2025 |
| Bifs Holdings Limited | Witham | 2025 |
| Big 5 Holdings Limited | Lymington | 2021 |
| Big 7 Holdings Ltd | South Ockendon | 2025 |
| Big a Investment GP Limited | London | 2018 |
| Big Bale Holdings Limited | Goole | 2018 |
| Big Bamboo Project Developments Limited | Greater London | 2022 |
| Big Bang Capital UK Ltd | St. Albans | 2019 |
| Big Barworks Bars Limited | London | 2025 |
| Big Barworks Bidco Limited | London | 2025 |
| Big Barworks Limited | London | 2025 |
| Big Beach Holdings Ltd | Porthcawl | 2026 |
| Big Bear Construction Group Limited | Swaffham | 2025 |
| Big Bear Group Limited | Maldon | 2025 |
| Big Bear Trades Ltd | Leicester | 2026 |
| Big BEN Venture Partners Ltd. | London | 2016 |
| Big Betty Food Company Group Limited | Marlow | 2022 |
| Big Black Dog Investments Limited | Harrow | 2017 |
| Big Blue Productions Limited | London | 2023 |
| Big Boss Capital Limited | Doncaster | 2020 |
| Big Boss Holdings Limited | Leicester | 2018 |
| Big Box Bidco UK Limited | London | 2016 |
| Big Box Midco UK Limited | London | 2016 |
| Big Box Property Holdings Ltd | Crawley | 2025 |
| Big BOY Holding's Limited | Godalming | 2025 |
| Big Brain HC Ltd | London | 2025 |
| Big Brands Group Ltd | Chichester | 2024 |
| Big Brisket Limited | Edgware | 2021 |
| Big Bump Ltd | Lincoln | 2026 |
| Big BUS Tours EU Limited | London | 2018 |
| Big BUS Tours Group Holdings Limited | London | 2015 |
| Big BUS Tours Group Limited | London | 2015 |
| Big BUS Tours Holdings 1 Limited | London | 2015 |
| Big BUS Tours Holdings 1A Limited | London | 2018 |
| Big BUS Tours Holdings 2 Limited | London | 2015 |
| Big BUS Tours Newco 1 Limited | London | 2020 |
| Big BUS Tours Newco 2 Limited | London | 2020 |
| Big BUS Tours Newco 3 Limited | London | 2020 |
| Big Button Holdings Limited | Birmingham | 2017 |
| Big Chair Solutions Limited | Stourport-On-Severn | 2023 |
| Big Chill Group Limited | Chatham | 2005 |
| Big Commercial Assets Limited | Harlow | 2023 |
| Big Cube Investments Ltd | London | 2023 |
| Big D Enterprises Limited | Littlehampton | 2003 |
| Big Daddy Foods Limited | Newry | 2021 |
| Big Dive (UK) Ltd | Stoke-On-Trent | 2023 |
| Big Dog Consultants Ltd | Long Stratton | 2013 |
| Big Dog Consulting Limited | Leicester | 2014 |
| Big Dog Investments Limited | Barnet | 2015 |
| Big E Holdings Ltd | Lytham St.Annes | 2022 |
| Big Fang Collective Ltd | Liverpool | 2018 |
| Big Fang Holdings Limited | Liverpool | 2021 |
| Big FAT Bunny Investments Limited | Stratford Upon Avon | 2025 |
| Big Finance Holdings Ltd | Willenhall | 2016 |
| Big Fish Holdings 1 Ltd | Manchester | 2021 |
| Big Fish Holdings Limited | Heckmondwike | 2021 |
| Big Fish Ventures Ltd | Nottingham | 2023 |
| Big Foot Investments Ltd | London | 2025 |
| Big Gate Holdings Limited | Newry | 2024 |
| Big Giraffe Capital Limited | Preston | 2016 |