The house flag of the Booth Steamship Co. Ltd, Liverpool. A white rectangular flag bearing a red saltire. There is a blue 'B' in the centre. The blue 'B', originally entirely placed on the red, was enlarged in 1947 and again in 1950 when the saltire was broken in the centre. The flag is made of a wool and synthetic fibre bunting. It has a cotton hoist and is machine sewn. A rope and toggle is attached.

The shipping company was founded in 1863 by Charles and Alfred Booth. The brothers were interested in exploiting recent improvements to steam vessels that were making them more commercially viable as cargo carriers. The business became the Booth Steamship Company in 1881, running a steamer service to Northern Brazil that benefited from the booming rubber trade and the transport of emigrants.

The route from Liverpool was made triangular with a stop at Galveston on the way back. Singleton's Red Cross Line was amalgamated to form Booth Steamship Company Ltd. Rubber production was moved to the Far East in the interwar period and trade with Brazil shrunk. In 1946 the company was sold to the Vestey Group. All the group's ships were pooled under Blue Star Ship Management Ltd in 1975.