| Buchanan Orthotics Limited | Glasgow | 1974 |
| Buchanan's (Northern Ireland) Limited | Ballyclare | 2000 |
| Buchanans (Scotland) Limited | Greenock | 1988 |
| Buchans Ices Ltd | Fraserburgh | 2024 |
| Buchan’S Kennels Limited | Stoke-On-Trent | 2024 |
| Bucher Hydraulics Limited | Nuneaton | 1989 |
| Bucher Municipal Limited | Surrey | 1924 |
| Buck and Hare Limited | Paisley | 2014 |
| Buck and Lloyd (Sheffield) Limited | Bakewell | 2004 |
| Bucket List Ltd. | London | 2021 |
| Buckfast Organic Bakery Limited | Newton Abbot | 2003 |
| Buckholt Masonry Ltd | Worcester | 2026 |
| Buckhurst Investments Limited | Coulsdon | 1966 |
| Buckie Butchers Ltd | Inverurie | 2026 |
| Buckies Bakes Ltd | Tetbury | 2021 |
| Buckingham Charles Ltd | Aberdeen | 2022 |
| Buckingham Engineering Ltd | Nottingham | 2010 |
| Buckingham Engineering Mobility Systems Ltd | Leighton Buzzard | 2002 |
| Buckingham Healthcare Services Limited | Poole | 2017 |
| Buckingham Interiors Ltd | Leicester | 2014 |
| Buckingham International Group Ltd | Milton Keynes | 2018 |
| Buckingham Magnetics Ltd | Borehamwood | 2020 |
| Buckingham Stone Ltd | Cardiff | 2020 |
| Buckingham Woodcraft Ltd | Milton Keynes | 2022 |
| Buckinghamshire Cheese Ltd | Milton Keynes | 2024 |
| Buckinghamshire Glazing Ltd | Chalfont St Giles | 2020 |
| Buckla Limited | London | 2026 |
| Buckland Industries Ltd | Beaworthy | 2021 |
| Buckland Media Group Limited | Deal | 1974 |
| Buckland Rail Limited | Mansfield | 2008 |
| Buckland Timber Limited | Crediton | 2013 |
| Buckland-Waite Ltd | London | 2025 |
| Buckleberry Limited | Saltaire | 1999 |
| Buckler Engineering Services Limited | Bath | 1999 |
| Bucklers Hard Boat Builders Limited | St. Albans | 1971 |
| Buckley (Europe) Limited | London | 2004 |
| Buckley Foods Limited | Crewe | 2002 |
| Buckley Industrial Limited | Coventry | 2014 |
| Buckleys (Uvral) Limited | Folkestone | 1942 |
| Buckman Laboratories Limited | Stockport | 1985 |
| Bucks & Co INT. Limited | Preston | 2016 |
| Bucks Air CON Ltd | Nottingham | 2018 |
| Bucks Blasting and Powder Coating Ltd | South Molton | 2022 |
| Bucks Blinds Ltd | Aylesbury | 2023 |
| Bucks Catering Maintenance Limited | Leighton Buzzard | 2014 |
| Bucks Concrete Limited | Waltham Abbey | 2019 |
| Bucks County Electrical Ltd | High Wycombe | 2016 |
| Bucks DIE Casting Company Limited(The) | Egham | 1941 |
| Bucks Garage Services Ltd | Hull | 2017 |
| Bucks Gym Services Limited | Princes Risborough | 2021 |
| Bucks Joinery Limited | Winslow | 2025 |
| Bucks Mobile Tyres Ltd | Gerrards Cross | 2025 |
| Bucks Polythene Limited | Leicester | 1989 |
| Bucks Tube Formers Limited | Aylesbury | 2020 |
| Buckshaw Fabrications Ltd | Chorley | 2017 |
| Buckwear UK Ltd | Leeds | 2024 |
| Buckwheat Bakery Ltd | Dorchester | 2024 |
| Buckwood (Environmental) Ltd | Oxford | 2021 |
| Bucky Brigada Media Ltd | London | 2025 |
| Bucovina Bakery Limited | Edgware | 2013 |
| Bucuris Ltd | Bacup | 2017 |
| BUD Designs Limited | Penrith | 2023 |
| BUD Fabrications Limited | Ashford | 2020 |
| Budare London Ltd | Hitchin | 2020 |
| Budberry Birmingham Clothing and Apparel Ltd | London | 2025 |
| Budbrooke Signs Limited | Warwick | 2003 |
| Budd (Shirt Makers) Limited | London | 1933 |
| Buddha Beachwear Limited | Sidcup | 2013 |
| Buddhahealingo Limited | London | 2025 |
| Buddhas Tree Limited | Manchester | 2010 |
| Buddhavale Limited | Hereford | 2019 |
| Buddi Limited | Rickmansworth | 2004 |
| Buddleys Limited | Chesham | 2023 |
| Buddy Direct Ltd | Leighton Buzzard | 2016 |
| Buddy Kombucha Limited | Cupar | 2019 |
| Buddy Marine Ltd | Cambridge | 2024 |
| Buddy Tools UK Ltd | Southampton | 2015 |
| Buddygrip Ltd | Closeburn | 2023 |
| Buddys Choice Ltd | Exeter | 2026 |
| Buddywood Ltd | London | 2024 |
| Bude Coastal Brewery Ltd | Bude | 2024 |
| Budee Ltd. | London | 2023 |
| Budelpack Cosi Ltd. | Cardiff | 1959 |
| Budenberg 4B Group Limited | Altrincham | 1996 |
| Budenberg Gauge Company Limited | Altrincham | 1902 |
| Budenberg Instrumentation Limited | Altrincham | 2010 |
| Budenberg Limited | Oldham | 2008 |
| Budge Nutrition Ltd | Ashbourne | 2025 |
| Budget Beds Leeds Limited | Leeds | 2026 |
| Budget Blinds Limited | Bolton | 2001 |
| Budget Blinds Plus Ltd | Blackpool | 2008 |
| Budget Cases Limited | St Helens | 2006 |
| Budget Clarity Ltd | London | 2026 |
| Budget Kitchens & Worktops Ltd | Sheffield | 2023 |
| Budget Kitchens & Worktops Online Ltd | Sheffield | 2024 |
| Budget Locksmiths (SW) Ltd | Plymouth | 2025 |
| Budget Paper Supplies Limited | Helpston, Peterborough | 1981 |
| Budget Print and Sign Limited | Stalybridge | 2024 |
| Budget Stairlifts Limited | Steeton Bradford | 1999 |
| Budget Steel and Fencing Ltd | Feltham | 2020 |