| Britannia Refined Metals Limited | Kent | 1930 |
| Britannia Refractory Products Limited | Alfreton | 2017 |
| Britannia Safes Limited | Newcastle Under Lyme | 2019 |
| Britannia Scientific Instruments Limited | Oldham | 2017 |
| Britannia Silverworks Ltd | Maidenhead | 2026 |
| Britannia Soft Drinks Limited | Hemel Hempstead | 1896 |
| Britannia Storage Management Ltd | Colchester | 2011 |
| Britannia Storage Systems Limited | Colchester | 1982 |
| Britannia Superfine Ingredients Ltd | Polegate | 2025 |
| Britannia Superfine Limited | Dittons Road, Polegate | 1953 |
| Britannia Tailoring Ltd | Manchester | 2022 |
| Britannia Technopolymers Limited | Nelson | 2016 |
| Britannia Textile Co. Limited | Leeds | 1984 |
| Britannia Trade Limited | London | 2019 |
| Britannia Traders Limited | London | 2014 |
| Britannia Transworld Ltd | Dagenham | 2011 |
| Britannia Woodworking Company Ltd | Buxton | 2000 |
| Britannia Yachts Ltd | Tavistock | 2021 |
| Britannia's Blitz Ltd. | London | 2025 |
| Britannic Furniture Ltd | Manchester | 2019 |
| Britannic Lifts Ltd | Harrogate | 2019 |
| Britannic Pharma Ltd | Alcester | 2018 |
| Britannica Limited | Dartford | 2020 |
| Britanova Medic Ltd | Northern Ireland | 2025 |
| Britash Ltd | Torquay | 2026 |
| Britax Excelsior Limited | Andover | 1934 |
| Britbayib Ltd | London | 2024 |
| Britbev Group Limited | Margate | 2025 |
| Britcare Laboratorie Ltd | Kington | 2024 |
| Britcell Ltd | Hook | 2022 |
| Britchem Limited | Beverley | 2002 |
| Britcher Watches Limited | Hayling Island | 2023 |
| Britclean (U.K.) Limited | Stoke On Trent | 1995 |
| Britco Corporation Limited | London | 2020 |
| Britco Industries Ltd | Newcastle Under Lyme | 2026 |
| Britcold Ltd | London | 2019 |
| Britcool Ltd | Doncaster | 2025 |
| Britcraft Timber Windows and Doors Ltd | Waltham Abbey | 2025 |
| Britcraftshub Ltd | Lincoln | 2026 |
| Brite Blinds Limited | Brighton | 2004 |
| Briteair Systems Limited | Batley | 2009 |
| Britecho Co., Ltd. | London | 2021 |
| Britecom Solutions Ltd | Manchester | 2025 |
| Britek Emergency Battery Limited | Bolton | 2016 |
| Britelane Technologies Limited | Clevedon | 2024 |
| Britelectro Ltd | London | 2025 |
| Britenergy Ltd | London | 2023 |
| Briteprint Signs & Engraving Ltd | Billingham | 2012 |
| Britex Traders Ltd | Kirkcaldy | 2026 |
| Britfame Limited | Harrow | 1986 |
| Britfix Group Ltd | Oadby | 2026 |
| Britgenic Ltd | Brandon | 2020 |
| Britgreen Limited | London | 2019 |
| Britguard Systems Ltd | London | 2023 |
| Brithbath Ltd | London | 2026 |
| Britherm Control Limited | Beckenham | 2019 |
| Brithop Brewing Company Limited | Lewes | 2017 |
| Britian Windows Limited | Bradford | 2013 |
| Briticore Ltd | Ruislip, | 2025 |
| Britimed Ltd | Ruislip, | 2023 |
| Britisans Ltd | Stoke-On-Trent | 2018 |
| British Airways Avionic Engineering Limited | Harmondsworth | 1993 |
| British Airways Engineering Gatwick Limited | Harmondsworth | 2024 |
| British Airways Engineering Wales Limited | Harmondsworth | 1987 |
| British Airways Interior Engineering Limited | Harmondsworth | 1995 |
| British Aluminium Limited | London | 2000 |
| British American Solutions Ltd | London | 2012 |
| British American Tobacco (Corby) Limited | London | 2014 |
| British American Tobacco Exports Limited | London | 2004 |
| British and Midland Forgings Limited | West Bromwich | 1923 |
| British Autogard Limited | London | 2002 |
| British Bakels Limited | Bicester | 1947 |
| British Beef Company Limited | Preston | 1995 |
| British Bung Manufacturing Company Limited(The) | West Yorkshire | 1978 |
| British Cables Company Limited | Manchester | 2012 |
| British Chlorophyll Company Limited | Lincoln | 1937 |
| British Cricket Balls Limited | Chelmsford | 1961 |
| British Crystal Ltd | Brierley Hill Dudley | 2005 |
| British Cured Pilchards Limited | Penzance | 1981 |
| British Diamond Wire DIE Company Limited | Poole | 1925 |
| British Driver-Harris Co.Limited | Salford Manchester | 1917 |
| British Electric Lamps Limited | Normanton | 1920 |
| British Energetics Limited | Saltash | 1995 |
| British Engineering Services Asset Reliability Strainstall Limited | Warrington | 2000 |
| British Estate Services (Properties) Limited | Thatcham | 1947 |
| British Filters Limited | Plymouth | 1999 |
| British Flowerpots Limited | Barnsley | 2023 |
| British Gaskets Limited | Sudbury | 1947 |
| British Group Ltd | Teddington | 2025 |
| British Heritage Collections Limited | Camberwell London | 1992 |
| British HO Models Limited | Poole | 2000 |
| British Honey Producers Limited | Buckingham | 1995 |
| British Industrial Truck Association Limited | Newbury | 1985 |
| British Jeffrey Diamond 100 Limited | Leeds | 1996 |
| British Leyland Limited | Ashford | 2006 |
| British Made Shutters Ltd | Evesham | 2024 |
| British Metal Treatments Limited | Great Yarmouth | 1958 |
| British Mica Company Holdings Limited | | 1995 |
| British Mica Company,Limited | | 1901 |
| British Mica Composites Limited | | 2006 |