A referendum on a war tax was held in Switzerland on 6 June 1915.[1] Voters were asked whether they approved of amending the constitution to introduce a one-off war tax during the First World War, which Switzerland remained neutral.[1] It was approved by a large majority of voters and all cantons,[1] the first time a referendum had been passed in every canton.[2]
The referendum was a mandatory referendum,[1] which required a double majority; a majority of the popular vote and majority of the cantons.[3] The decision of each canton was based on the vote in that canton.[3] Full cantons counted as one vote, whilst half cantons counted as half.[3]