| Blackwater Imaging Limited | London | 2019 |
| Blackwater Mill Limited | Poole | 2012 |
| Blackwater Pharma Ltd | Maldon | 2008 |
| Blackwater Podiatry Ltd | Maldon | 2025 |
| Blackwater Private Clinic Enniskillen Ltd | Enniskillen | 2026 |
| Blackwater Private Clinic Ltd | Armagh | 2021 |
| Blackwater Skin Ltd | Armagh | 2026 |
| Blackwell Associates Limited | Belfast | 2014 |
| Blackwell Medical Services Limited | Derby | 2006 |
| Blackwell Montessori Nursery Limited | Birmingham | 2013 |
| Blackwell Place Holdings Limited | Winchester | 2025 |
| Blackwood Care Ltd | Hamilton | 2025 |
| Blackwood Consultants Limited | London | 2017 |
| Blackwood Health Ltd | London | 2024 |
| Blackwood Housing Limited | Birmingham | 2020 |
| Blackwoods Medical Ltd | Leeds | 2014 |
| Blacodza Carers Limited | Kemberworth Park | 2014 |
| Blacon EYE Care Ltd | Wakefield | 2016 |
| Blad International Limited | Milton Keynes | 2015 |
| Bladder Health UK Limited | Birmingham | 2012 |
| Bladdercare Limited | Swansea | 2019 |
| Blade Pro Coaching Limited | Bolton | 2025 |
| Bladerunner Limited | Epsom | 2000 |
| Blades of Highcliffe Limited | Christchurch | 2015 |
| Bladon Dental Limited | Hornchurch | 2015 |
| Bladon Healthcare Ltd | Edenbridge | 2023 |
| Blaenau Gwent and Caerphilly Care & Repair | Blackwood | 2017 |
| Blaenmarlais Care Limited | Narberth | 2010 |
| Blair Edward Limited | Glasgow | 2007 |
| Blair House Care Home Limited | Bamber Bridge | 2012 |
| Blair House Limited | Belfast | 2004 |
| Blair Incorporation Limited | London | 2018 |
| Blair Muir Physiotherapy Ltd. | Glasgow | 2017 |
| Blair Orthopaedics Limited | Doncaster | 2021 |
| Blairgowrie Physiotherapy & Sports Injury Clinic Ltd. | Blairgowrie | 2014 |
| Blaise Care Limited | Bristol | 2024 |
| Blaise Medical Ltd | York | 2020 |
| Blak Diamond Social Care Limited | Romford | 2009 |
| Blake Court Limited | Warwick | 1997 |
| Blake Dental Limited | Witham | 2021 |
| Blake Health Ltd | Cheltenham | 2023 |
| Blake J Ltd | London | 2007 |
| Blake Johnson Healthcare Ltd | Hemel Hempstead | 2021 |
| Blake Locums Ltd | Birmingham | 2021 |
| Blake UK Care Services Limited | Bridlington | 2014 |
| Blake-James Urology Ltd | York | 2019 |
| Blakehill Healthcare Limited | Chippenham | 2015 |
| Blakeland Support Services Ltd | Birmingham | 2019 |
| Blakeridge Limited | Barry | 2011 |
| Blakeshields Limited | Slough | 1997 |
| Blakewater Homecare Services Ltd | Blackburn | 2020 |
| Blakewater Medicals Ltd | Blackburn | 2017 |
| Blanc Dental Hygiene Suite Ltd | Basildon | 2021 |
| Blanca Iglesias Limited | London | 2020 |
| Blanche Health UK Limited | Harlow | 2020 |
| Blanche Kadjo Ltd | Ellesmere Port | 2023 |
| Blanche Smile Studio Limited | London | 2013 |
| BLANCHE221 Limited | London | 2022 |
| Blanchworth Care Limited | Berkeley | 1999 |
| Blancke Medical Consultancy Limited | Bristol | 2012 |
| Blanco Activities Ltd | Fareham | 2021 |
| Blanco Services Ltd | Bristol | 2023 |
| Blanco-Noor Limited | Swindon | 2011 |
| Blancoburro Limited | High Wycombe | 2023 |
| Blandford House (UK) Limited | Uxbridge | 2015 |
| Blane Medical Limited | Market Drayton | 2019 |
| Blanefield Care Group Limited | Glasgow | 2019 |
| Blanefield Care Limited | London | 2011 |
| Blaney Mccartan Ltd | Belfast | 2008 |
| Blank Canvas Studio Ltd | Dartford | 2022 |
| Blank Theory Ltd | London | 2025 |
| Blanke Slate Community Interest Company | Hastings | 2007 |
| Blankenstein Imaging Limited | Penicuik | 2026 |
| Blankenstein Limited | Penicuik | 2019 |
| Blanks Medical Ltd | Nottingham | 2023 |
| Blantyre Family Dental Care Limited | Glasgow | 2021 |
| Blaq Biscuit Ltd | Southampton | 2021 |
| Blaqstone Healthcare Ltd | Doncaster | 2022 |
| Blarksurs Limited | Southampton | 2018 |
| Blaser Chiropractors Limited | Glasgow | 2003 |
| Blast Boxing CIC | Dalkeith | 2024 |
| Blast Light Ltd | Shepton Mallet | 2018 |
| Blauw Bear Limited | Hastings | 2007 |
| Blaze Integrated Services Ltd | Feltham | 2019 |
| Blaze Vintage Ltd | Halesowen | 2023 |
| Blazing Beacon Ltd | London | 2025 |
| Blazing Stars Childminding Services Limited | London | 2016 |
| Bledington & Foscot Community Association Limited | Chipping Norton | 2013 |
| Bleed KIT Technology Ltd | Formby | 2023 |
| Bleedwell C.I.C. | London | 2025 |
| Bleep 360 Care Limited | Camberley | 2017 |
| Bleep Care Limited | Luton | 2013 |
| BLEEP24 Healthcare Ltd | Manchester | 2020 |
| Bleiker & Williams Ltd | Lincoln | 2011 |
| Bleinheim Vision Limited | Reading | 2022 |
| Blemish Limited | Bury | 2004 |
| Blend Skin & Beauty Clinic Ltd | Northwich | 2020 |
| Blend Skin Clinic Ltd | Northwich | 2020 |
| Blend Therapy Ltd | Barnsley | 2025 |
| Blended Therapies Ltd | Faversham | 2006 |