What Is a Referendum? Types, Rules and Examples

A referendum is a vote in which the electorate decides, or gives its view on, a specific question, such as a constitutional change, a law or a treaty, rather than choosing people to represent them. Referendums can be binding or advisory, and mandatory (the constitution requires one) or optional (parliament, the government or a group of citizens can call one).

Most democracies in Europe are primarily representative, and referendums are a supplement. How often they are held and what they can decide varies enormously, from frequent national votes in Switzerland to countries that have never held a national referendum.

The main types

Type	Who triggers it?	Effect	Example
Mandatory referendum	The constitution, automatically	Usually binding	Constitutional amendments in Ireland and Switzerland
Optional referendum by citizens	A set number of voters by signature	Binding or suspensive	Swiss optional referendum against a new federal law
Optional referendum by parliament or minority	Parliament or a share of its members	Binding or advisory	Several constitutions allow a parliamentary minority to request a vote
Government-called referendum (plebiscite)	Government or head of state	Often advisory	Ad hoc referendums in the UK
Abrogative referendum	Citizens or regions	Repeals an existing law	Italy
Citizens’ initiative leading to a vote	Citizens with their own proposal	Binding or advisory	Swiss popular initiative

The last row is technically a different instrument: when citizens propose a new text themselves, it is usually called an initiative. The differences are explained in referendum vs. initiative vs. plebiscite.

Binding or advisory?

• Binding means the result takes legal effect or obliges the authorities to act.
• Advisory (or consultative) means the result is formally a recommendation. Parliament or government decides afterwards, although advisory results often carry great political weight.

The United Kingdom is a frequently cited example: referendums there are called by an Act of Parliament for a specific question and are, in legal terms, usually advisory unless the Act provides otherwise.

Thresholds and safeguards

Referendum rules often add conditions beyond a simple majority:

• Turnout quorum: a minimum share of the electorate must take part. Italy’s abrogative referendums, for example, are valid only if a majority of those entitled to vote participate.
• Approval quorum: a minimum share of the whole electorate must vote yes.
• Double majority: a majority of voters and a majority of territorial units, as in Switzerland’s ‘people and cantons’ rule. See double majority.
• Waiting periods and subject limits: some constitutions exclude topics such as taxes, budgets or international treaties from citizen-triggered votes.

Each of these is a trade-off between legitimacy and the risk that a vote fails for reasons other than the yes/no balance. More on how quorums work is on majority and quorum.

The ballot question

The wording of the question can influence the result. Good practice, as recommended by electoral bodies, includes a neutral, short question, avoiding leading terms, and making clear what each answer means in practice. In the UK, the Electoral Commission assesses the intelligibility of proposed referendum questions. The same principles apply to votes in clubs and companies; see writing ballot questions.

Referendums in Europe at a glance

• Switzerland holds several federal votes every year, with mandatory and optional referendums and popular initiatives.
• Ireland must hold a referendum for every constitutional amendment.
• Italy combines abrogative and constitutional referendums.
• Denmark uses referendums for constitutional changes and certain transfers of sovereignty.
• Germany has no general national referendum, but many votes at state and municipal level.

A fuller comparison is in referendums in Europe, and the history of votes on European treaties is on EU treaty referendums. The Centre for Research on Direct Democracy (C2D) maintains a database of referendums worldwide.

Arguments in the debate, briefly

Supporters of referendums point to direct legitimacy and citizen engagement. Critics point to the reduction of complex questions to yes or no, low turnout and the influence of campaign spending. Both views are part of an ongoing academic and political debate; this page does not take a position.

How a referendum typically runs

1. Trigger: constitutional requirement, parliamentary decision or collection of signatures.
2. Question and date are set, often with a review of the wording.
3. Campaign period, sometimes with spending limits and official information material.
4. Vote, in person, by post and in a few places online.
5. Count and certification of the result by the electoral authority.
6. Implementation, either automatically (binding) or through a decision by parliament (advisory).