| Blitz Pest Control & Drain Clearance Services Ltd | Northampton | 2024 |
| Blitz-It (Cleaning) Limited | Hartlepool | 2006 |
| Blitz-Uk Ltd | London | 2025 |
| Blitzo Logistics Ltd | Mitcham | 2024 |
| Blitzy Occasion Ltd | Bolton | 2024 |
| Blizzard Music Limited | Holborn | 1981 |
| Blizznova Ltd | London | 2025 |
| BLJ Services Limited | Warwick | 2025 |
| BLK Inkorporated Ltd | Glossop | 2022 |
| BLK South Ltd | Princes Risborough | 2013 |
| Bllan Beauty Ltd | Stockport | 2015 |
| Bllbas Group Ltd | Preston | 2024 |
| Blloom Beauty Limited | High Wycombe | 2022 |
| Blnk.Barbers Ltd | Lincoln | 2024 |
| BLO by BLO Limited | Hertford | 2024 |
| BLO Hair and Beauty Ltd | Musselburgh | 2023 |
| BLO Hair Studio Ltd | Stamford | 2020 |
| BLO I Ltd | Croydon | 2019 |
| BLO II Ltd | Croydon | 2017 |
| BLO Salon Ltd | Musselburgh | 2017 |
| BLOBAR67 Limited | Buckhurst Hill | 2017 |
| Blobfish Limited | London | 2014 |
| Bloc (UK) Limited | High Wycombe | 2004 |
| Bloc Clean Services Limited | London | 2012 |
| Bloc Enterprise Ltd | Sheffield | 2022 |
| BLOC41 Ltd | Birmingham | 2023 |
| Block and Bone Limited | Liverpool | 2019 |
| Block Consulting Ltd | Rotherham | 2024 |
| Block D Jack Clow Road (Freehold) Limited | Loughton | 2017 |
| Block Limited | Bishop'S Stortford | 1995 |
| BLOCK3 Group Ltd | Greater London | 2019 |
| Blockbond Limited | Dunmow | 1996 |
| Blockchain Distribution Ltd | Leicester | 2018 |
| Blockchain Marketing Solutions Limited | Cambridge | 2008 |
| Blockdaemon UK Limited | London | 2022 |
| Blockdale Properties Ltd | Ashton-Under-Lyne | 2023 |
| Blocked Urinal.Com Limited | Bedford | 2023 |
| Blockhouse Building Limited | Sherborne | 2019 |
| Blocks 1 2 and 3 Langley Square Management Company Limited | London | 2018 |
| Blockwork Bristol Ltd | Westbury-On-Trym | 2017 |
| Bloem Care Ltd | South Ruislip | 2018 |
| Bloemers Limited | London | 2009 |
| Blog Smart Agency Limited | London | 2018 |
| Blogb Limited | London | 2025 |
| Bloggs Salons Ltd | Bristol | 2010 |
| Blok ‘N’ Mesh Manufacturing Limited | Leytonstone | 2021 |
| Bloke Barber Limited | Swansea | 2021 |
| Bloke Barbers Chorley Ltd | Chorley | 2025 |
| Blokes (Lichfield) Limited | Rugeley | 2019 |
| Blokes Grooming Ltd | London | 2017 |
| Blokeys Limited | Stevenage | 2024 |
| Blom Creative Ltd | Glasgow | 2017 |
| Blomstra Skin Limited | Preston | 2017 |
| Blond Salon Ltd | Glasgow | 2019 |
| Blond. (Harrogate) Ltd | Harrogate | 2023 |
| Blonde Ambition (Wales) Limited | Barry | 2014 |
| Blonde Ambition Salon Ltd | Halstead | 2025 |
| Blonde and Beyond Ltd | Seaford | 2025 |
| Blonde D'Aquitaine Breeders Society of Great Britain Limited(The) | Carlisle | 1971 |
| Blonde DYE Bleach Limited | Benfleet | 1997 |
| Blonde Hair Limited | Cottingham | 2012 |
| Blonde Hair Salon Ltd | Crewe | 2018 |
| Blonde Hairdressing by Stephanie Limited | Dundee | 2023 |
| Blonde Hairdressing Limited | Bootle | 2016 |
| Blonde on Blonde (Birmingham) Ltd | Birmingham | 2009 |
| Blonde Salon Limited | Norwich | 2007 |
| Blonde Savvies Ltd | London | 2026 |
| Blonde Studio London Ltd | London | 2024 |
| Blonde+Bronzed Ltd | Herne Bay | 2020 |
| Blondee Boujee Ltd | Liverpool | 2024 |
| Blondee Ltd | Shipley | 2025 |
| Blondes and Browns Ltd | London | 2018 |
| Blondes of Brentwood Limited | Brentwood | 2016 |
| Blondez Ltd | Gloucester | 2019 |
| Blonde’S Studio Ltd | High Wycombe | 2023 |
| Blondie & the Bears Limited | Leatherhead | 2016 |
| Blondie Beauty Academy Ltd | London | 2023 |
| Blondie Locks Ltd | Wallsend | 2024 |
| Blondiera Hair Ltd | Cleethorpes | 2026 |
| Blondies Hair Design Limited | Birmingham | 2020 |
| Blondies [WM] Ltd | Wednesbury | 2022 |
| Blonds Salon Limited | Antrim | 2016 |
| Bloo Rope Solutions Ltd | Peterhead | 2023 |
| Blood and Bandages by MT Limited | Crawley | 2016 |
| Blood Fitness Ltd | London | 2024 |
| Blood of Angels Limited | Cambridge | 2017 |
| Bloodhound Rescue and Support Ltd | Easlington Colliery | 2018 |
| Bloodline Planning Ltd. | Cardiff | 2019 |
| Bloodstock Media Limited | Weybridge | 2005 |
| Bloodstone Tattoo Collective Ltd | Lurgan | 2018 |
| Bloody Mary Design Limited | London | 2011 |
| Blooloop Employee Benefits Limited | Devon | 2024 |
| Bloom & Blush Ltd | London | 2026 |
| Bloom & Glow CIC | Wembley | 2025 |
| Bloom & Grey Limited | Doncaster | 2024 |
| Bloom & Prune Ltd | Rye | 2017 |
| Bloom Accountancy Services Ltd | Westerham | 2019 |
| Bloom Aesthetics Training Limited | Barnsley | 2020 |
| Bloom and Cadogan Ltd | Cheltenham | 2003 |
| Bloom and Success Limited | Bournemouth | 2019 |