Shell-Mex & BP Ltd was founded in 1931 to market and sell the petrol and oil products of Shell and BP in the UK. Shell and BP each owned 40% and the Eagle Group owned the remaining 20%.

In 1938, the principal suppliers of petrol in the UK, including Shell-Mex & BP Ltd, joined together with Government approval to form the Petroleum Board, established to consider the problems of petroleum distribution in the event of war. On 3 September 1939, the Board became an executive body under Government direction. The Petroleum Board was eventually dissolved in June.

Shell-Mex & BP Ltd was closed down in 1975 with the operations split between its Shell and BP according to their shareholdings.