History

The Efficiency Decoration was established by King George V on October 17, 1930. The Decoration was created to replace the Territorial Decoration and was awarded to part-time officers of the Territorial Army, Indian Voluntary Forces, and the Colonial Auxiliary Forces in recognition of 20 years of service, with war service counting as double. The qualifying period was reduced to 12 years in 1949. The Decoration was superseded in the United Kingdom by the Volunteer Reserve Service Medal in 2000. However, some Commonwealth countries continued to issue the award.

Clasps depicting the ruling monarch's cypher and the date of the award on the reverse were also introduced in 1949 to reward an additional 6 years of service.

The Decoration features a suspension bar denoting the country or area of service. A suspension with the inscription "TERRITORIAL" is worn to denote service in the Territorial Army in the United Kingdom. In 1969, following the introduction of the Territorial and Army Volunteer Reserve, the suspension bar was altered to read, "T & AVR" and a new ribbon pattern was issued for wear with the award. However, the suspension bar was reverted back to "TERRITORIAL" in 1982.

British recipients of the Decoration are entitled to the post-nominal letters "TD" and Commonwealth recipients are entitled to the post-nominal letters "ED."

There are multiple versions of the Medal which vary by the cypher of the ruling Monarch. Only versions with clasps with an image are featured and there may be additional versions.