| Bioquip Limited | Tewkesbury | 2011 |
| Bioregional Minimills (UK) Limited | London | 1997 |
| Bioregit Ltd | London | 2022 |
| Biorex Diagnostics Ltd | Antrim | 2003 |
| Biorex Food Diagnostics Limited | Antrim | 2016 |
| Bios Europe Limited | | 1999 |
| Biosafe Medical Products Co. Limited | London | 2013 |
| Bioschlafsofa Ltd | Manchester | 2024 |
| Biosec Intergalactic Limited | Mitcham | 2024 |
| Biosect Limited | Macclesfield | 2024 |
| Biosef Ltd | London | 2023 |
| Bioseiche Ltd | London | 2021 |
| Bioself Technology Ltd | London | 2015 |
| Bioseneca Holdings Limited | London | 2020 |
| Biosensori Limited | London | 2026 |
| Biosensors International UK Ltd | London | 2019 |
| Bioshade Limited | Keighley | 2009 |
| Bioshield AG Ltd | Greater London | 2024 |
| Biosimax Lifesciences Ltd | Manchester | 2024 |
| Biosirius Ltd | Poole | 2021 |
| Biosite Systems Limited | Solihull | 2010 |
| Biosmax Limited | West Midlands, England | 2025 |
| Biospag Limited | Loughborough | 2012 |
| Biospan Limited | London | 2020 |
| Biospec Feeds Limited | Broadstone | 2020 |
| Biospeedia SPV Ltd | Saffron Walden | 2020 |
| Biosphere Bikes | Girvan | 2018 |
| Biosphere Renewables Ltd | Manchester | 2025 |
| Biostatus Ltd | Shepshed | 1995 |
| Biostimulants Ltd | London | 2023 |
| Biostraw Ltd | Leeds | 2018 |
| Biostream Ltd | London | 2024 |
| Biostrive Ltd | Ayr | 2025 |
| Biosure Global Ltd | Grays | 2018 |
| Biosuspensions Limited | Shepshed | 2008 |
| Biosyn Fusion Ltd | Edgware | 2025 |
| Biosync Limited | Bury St. Edmunds | 2024 |
| Biosynth Europe Limited | London | 2005 |
| Biosynth Laboratories Limited | Newbury | 1999 |
| Biosynth Limited | Newbury | 2006 |
| Biosysai Global Ltd | London | 2020 |
| Biotage GB Limited | Hengoed | 1971 |
| Biotalife Healthcare Ltd | Mansfield | 2020 |
| Biotch Ltd | Great Missenden | 2026 |
| Biotec Diagnostics UK Ltd | Bristol | 2014 |
| Biotec UK Ltd | Radstock | 2019 |
| Biotech Design and Validation Ltd. | Warwick | 1995 |
| Biotech Life Sciences Ltd | London | 2019 |
| Biotech Research Laboratories Limited | London | 2020 |
| Biotechflow Ltd | Stroud | 2010 |
| Biotechflow Production Limited | Stroud | 2021 |
| Bioteknic Limited | Ashbourne | 2025 |
| Bioterra UK Limited | London | 2023 |
| Biotherics Limited | Shepshed | 2009 |
| Biotica Chemicals Ltd. | Wolverhampton | 2022 |
| Biotoolomics Limited | Consett | 2005 |
| Biotrack Ltd | Wareham | 2017 |
| Biotrans Pole Sleeves UK Ltd | Edinburgh | 2020 |
| Bioup Labs Limited | London | 2021 |
| Biovantic Pharma Limited | London | 2020 |
| Biovec Ltd | Edinburgh | 2023 |
| Bioveg Ltd | Boston | 2018 |
| Bioverse Ltd | Banstead | 2022 |
| Biovetis Ltd | Walton-On-Thames | 2025 |
| Bioviron International Limited | Swindon | 2007 |
| Biovit Ltd | Tenby | 2023 |
| Biovital UK Limited | Bromley | 2018 |
| Biovolt Ltd | Hornchurch | 2025 |
| Biovoltmedical Ltd | Hornchurch | 2025 |
| Biowizard Ltd. | Stevenage | 2015 |
| Biowool Regen Ltd | Harrow | 2025 |
| Bioworld International Limited | Hinckley | 2014 |
| Biox Limited | Royston | 1984 |
| Biox Systems Limited | London | 2000 |
| BIP (Oldbury) Limited | Oldbury | 2004 |
| BIP Organics Limited | Middlewich | 2006 |
| Biplas Medical Limited | Pontyclun | 2008 |
| Bipolar Disorder CIC | London | 2015 |
| Bipv Limited | Newport | 2013 |
| Birch & Co. Holdings Ltd | Market Drayton | 2026 |
| Birch Base Limited | Hassocks | 2016 |
| Birch Bedrooms (Nottingham) Ltd | London | 2025 |
| Birch Bedrooms Limited | Coalville | 1996 |
| Birch Bespoke Interiors Ltd | Aylesbury | 2021 |
| Birch Chemicals Limited | Barnetby | 1999 |
| Birch Close Trading Ltd | Birmingham | 2016 |
| Birch Construction EA Ltd | Wymondham | 2021 |
| Birch Fabrication Limited | Antrim | 2024 |
| Birch Farm Old Fashioned Ice Cream Ltd | Heywood | 2022 |
| Birch Mountain Furniture Ltd | Dunkeld | 2024 |
| Birch Roasting Co Ltd | Isle Of Skye | 2023 |
| Birch Sheet Metal Limited | Hull | 1996 |
| Birch Solutions UK Limited | Barnetby | 2013 |
| Birch Tree Interiors Limited | Truro | 2026 |
| Birch Villa Cakes Ltd | Wellington | 2018 |
| Birch Welding Solutions Limited | Rotherham | 2023 |
| Birch Works Limited | Folkestone | 2023 |
| BIRCH2 Limited | Hull | 2000 |
| Birchall Developments Limited | Southport | 2007 |
| Birchell Marine Limited | Torquay | 2009 |