The South of Scotland Electricity Board was formed as a result of the Electricity Reorganisation (Scotland) Act 1954. On 1st April 1955, the two southern Scottish Area Electricity Boards were merged to form the South of Scotland Electricity Board (SSEB). The SSEB generated, transmitted and distributed electricity throughout the south of Scotland and a few towns in northern England. The SSEB was privatised in 1991 and became Scottish Power and Scottish Nuclear.
Of the two types of overprint used by the utility, the initials only version is the least common.