As posted by Chris Paton on his "The Genes Blog", Ancestry.co.uk is opening up their record set
British Army WWI Medal Rolls Index Cards, 1914-1920It will be free till November. This is to mark the centenary of the Battles of the Hindenburg Line. See more information here.
The collection is accessible at https://search.ancestry.co.uk/search/db.aspx?dbid=1262&o_xid=91999&o_lid=91999