| Busy BEE Clean Ltd | London | 2014 |
| Busy BEE Fencing Limited | Nottingham | 2004 |
| Busy BEE Learning Ltd | Leicester | 2022 |
| Busy BEE Workshop Ltd | Nottingham | 2023 |
| Busy Bees Cosmetics Limited | Sudbury | 2018 |
| Busy Bees Creative Studio Ltd | Halifax | 2025 |
| Busy Boards 123 Limited | Edgware | 2020 |
| Busy Fingers Printing Ltd | Cirencester | 2023 |
| Busy Fingers Sewing Co Limited | Windsor | 2012 |
| Busy Little Muslim Ltd | Ashton-Under-Lyne | 2025 |
| Busy Stitch Pro Limited | Southend-On-Sea | 2026 |
| Busybees Food Ltd | South Harrow | 2024 |
| Busyhands Collectibles Ltd | Stevenage | 2025 |
| Busylite Limited | Essex | 1981 |
| BUT GOD Ltd | Sidcup | 2026 |
| Butcher and Brine Ltd | Glasgow | 2018 |
| Butcher Bob's Ultimate Products Ltd | Peacehaven | 2018 |
| Butcher Buddy Limited | Bradford | 2026 |
| Butcher's Pet Care Limited | Thirsk | 1983 |
| Butchers Hook Food Services Ltd | Cardiff | 2020 |
| Butchers Printed Products Limited | Alcester | 1990 |
| Butcombe Brewery Limited | Bristol | 2003 |
| Butcombe Brewing Company Limited | Bristol | 2003 |
| Bute Blacksmiths Limited | Isle Of Bute | 2005 |
| Bute Boatbuilders Ltd | Port Bannatyne | 2018 |
| Bute Fabrics Limited | Isle Of Bute | 1977 |
| Bute Island Foods Ltd. | Isle Of Bute | 2002 |
| Bute Venison Ltd | Isle Of Bute | 2022 |
| Bute's Bounty Ltd. | Isle Of Bute | 2023 |
| Butec Business Machines Limited | Dudley | 2005 |
| Butek Group Limited | Billericay | 2019 |
| Butek Landline Limited | Billericay | 2014 |
| Butimak Global Limited | Oban | 2025 |
| Butler & England Ltd | Ditton | 2019 |
| Butler & Grace Ltd | Milton Keynes | 2014 |
| Butler & Pooch Limited | London | 2013 |
| Butler Boatyards Limited | Torquay | 2025 |
| Butler Country Estates Limited | Winchester | 2013 |
| Butler Craft Ltd. | London | 2021 |
| Butler M Ltd | Derby | 2018 |
| Butler Precision Engineering Ltd | Swansea | 2022 |
| Butler Printing Limited | Rotherham | 1995 |
| Butler Services Ltd | Paignton | 2021 |
| Butler Sheetmetal Limited | Colne | 2002 |
| Butler Signs Limited | London | 2018 |
| Butler Traditional Wooden Boats Limited | Truro | 2006 |
| Butler Valves and Fittings Limited | Birmingham | 1994 |
| Butler's Farmhouse Cheeses (Holdings) Limited | Preston | 1998 |
| Butler's PIE Company Limited | Brackley | 2017 |
| Butlers Auto Electrical Limited | Market Harborough | 2017 |
| Butlers Bakes Ltd | Peterborough | 2025 |
| Butlers Carpentry Limited | Tadley | 2016 |
| Butlers Farmhouse Cheeses (Parent) Limited | Preston | 2017 |
| Butlers Farmhouse Cheeses Limited | Preston | 1998 |
| Butlers Leap Mobile Limited | Coventry | 2022 |
| Butlers Trailers & Marquees Ltd | Randalstown | 2019 |
| Butor Village Ltd Ltd | London | 2024 |
| Butser Rubber Limited | Liss | 1978 |
| Butt Brand Ltd | Ilford | 2025 |
| Butt Juices Limited | Ashton-Under-Lyne | 2025 |
| Butt Nakd Bubbles Ltd | London | 2026 |
| Butt Sweets & Bakers Limited | Slough | 2025 |
| Buttah London Ltd | Borehamwood | 2024 |
| Butter & Scotch Ltd | Chelmsford | 2019 |
| Butter Adasi Health International Trading Co., Ltd | Cambridge | 2024 |
| Butter and Sugar Cakes UK Limited | Swansea | 2020 |
| Butter Bakery Ltd | Nottingham | 2025 |
| Butter Beam Ltd | Cromer | 2025 |
| Butter Believe IT Limited | London | 2018 |
| Butter Bike Co Limited | Winchester | 2019 |
| Butter Bothy Limited | Aberdeen | 2026 |
| Butter Drop Bakery Limited | Bury St. Edmunds | 2025 |
| Butter Oils and Herbs Ltd | Manchester | 2026 |
| Butter Street Ltd | Hastings | 2026 |
| Butterbloom Desserts Ltd | London | 2026 |
| Butterbrûlée Ltd | Leicester | 2021 |
| Butterbur and Sage Limited | Reading | 1983 |
| Buttercross Butchers Ltd | Market Drayton | 2021 |
| Buttercrust Limited | Edinburgh | 2024 |
| Butterdoughs Ltd | Weymouth | 2025 |
| Butterfield Illuminated Signs Limited | | 1970 |
| Butterfield MCR Limited | Ellesmere Port | 1985 |
| Butterfield Neon Service Limited | | 1964 |
| Butterfield Refrigeration Limited | Huddersfield | 2009 |
| Butterfield Sign Service Limited | West Yorkshire | 1976 |
| Butterfield Signs Limited | | 1946 |
| Butterfly Bakery Limited | Harlow, Essex | 2024 |
| Butterfly by T.Barnes Ltd | Salford | 2017 |
| Butterfly CGI Ltd | Salisbury | 2022 |
| Butterfly Colours Ltd | Leicester | 2026 |
| Butterfly Desserts Ltd | London | 2021 |
| Butterfly Embroidery Limited | Oldbury | 2003 |
| Butterfly Screen Print Limited | Mansfield | 2022 |
| Butterfly Snacks Ltd | Stockport | 2021 |
| Buttermilk Confections Limited | Bodmin | 2002 |
| Butternut Holdings Nominees Ltd | London | 2023 |
| Butterwick Bakery Limited | Rushden | 2021 |
| Butterwick Bakes Limited | Northampton | 2017 |
| Butterworths (Regia) Limited | Kent | 1959 |
| Butterworths Lenses Limited | Edinburgh | 2001 |