Overview
A by-election is a contest held to fill one or more vacancies that arise in a legislature or other elected body between regularly scheduled general elections. Often called a special election in some countries, a by-election affects only the constituency or seat that became vacant rather than the full membership of the chamber. The trigger, timing and method of conducting by-elections vary by jurisdiction.
Common causes and immediate procedure
Vacancies that prompt by-elections typically include the death or voluntary departure of an office-holder, for example through resignation, or formal removal following disqualification. A member may also lose eligibility to sit in office for legal reasons, such as being convicted or otherwise judged guilty of an offence, or for failing to meet statutory qualifications for political office. In some systems a vacancy is filled by a by-election; in others it is filled by appointment or by the next person on a party list.
Variations in name and practice
Different countries use different terms and rules. For example, the United States and the Philippines commonly use the phrase special election or special election process, while in India these contests are often referred to as bypolls. Procedures may specify a fixed window within which the by-election must be held after a vacancy, or they may give electoral authorities discretion. Some systems suspend primaries or shorten candidate nomination timelines to expedite the replacement.
Political significance and distinctive features
By-elections are frequently watched as measures of public opinion between general contests. They can change the balance of a narrowly divided legislature, provide an opportunity for new parties or independent candidates to gain visibility, and attract intense local campaigning despite typically lower turnout. They differ from recalls (which remove an incumbent by popular vote) and from runoffs (which resolve an indecisive result in a general election).
Examples and notable facts
- By-elections are single-constituency events and may be concentrated: for example, in the 1980s all 12 of the Unionist MPs in the British House of Commons resigned and their contests were held on the same day; these contests were nonetheless classified as by-elections (House of Commons example).
- In proportional representation systems that use closed party lists, vacancies are sometimes filled by the next unseated candidate rather than a by-election.
- Jurisdictions differ on whether appointments (such as elevation to a non-elected office) require a by-election; historic practices also varied.
Summary
By-elections are targeted electoral events used to maintain representation when a seat becomes vacant between general elections. Their names, schedules and consequences differ worldwide, but their core purpose—to restore representation for a constituency—is common. For procedural guidance consult the relevant electoral authority or statutory rules for the chamber in question (general elections context, legal considerations, Philippines practice).