by-election

A by-election (also spelled bye-election in Ireland, and also known as a special election in the United States and the Philippines, or a bypoll in India) is an election used to fill an office that has become vacant between general elections.
A vacancy may arise as a result of an incumbent's death or resignation, or when the incumbent becomes ineligible to continue in office (because of a recall, a prohibited dual mandate, criminal conviction, or failure to maintain a minimum attendance), or when an election is invalidated by voting irregularities. In some cases a vacancy may be filled by a method other than a by-election (such as the outgoing member's party nominating a replacement) or the office may be left vacant. These elections can be held anytime in the country.
An election to fill a vacancy created when a general election cannot take place in a particular constituency (such as if a candidate dies shortly before election day) may be called a by-election in some jurisdictions, or may have a distinct name (e.g., supplementary election, as in Australia).
By-elections differ from snap elections in that snap elections typically elect the entire legislative or parliamentary body, whereas by-elections are typically limited to only vacant positions. Furthermore, Recall elections are typically called before a member is removed from office, where by-elections are usually called after.

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