Three referendums were held in Switzerland during 1919.[1] The first two were held on 4 May on amending the constitution to add article 24ter on shipping, and on a constitutional amendment to impose a war tax.[1] Both proposals were approved by a majority of voters and cantons.[1] The third was held on 10 August on temporary amendments to article 73 of the constitution, and was also approved in spite of low turnout.[1]
All three referendums were mandatory referendums,[1] which required a double majority; a majority of the popular vote and majority of the cantons.[2] The decision of each canton was based on the vote in that canton.[2] Full cantons counted as one vote, whilst half cantons counted as half.[2]