An election recount is typically ordered or requested when the margin of victory in an election is extremely small, or when people believe that the election may have been dishonest. As a general rule, only one recount per election will be allowed, although people can potentially contest the results in a court to demand another recount or additional verification of the validity of the election. Recounts can get expensive and time consuming, and most governments prefer to avoid them, if possible.
There are two types of recounts. In mandatory recounts, certain conditions surrounding the election mean that the government is required to conduct an audit of the results. In these situations, the individual who loses can choose to waive the recount, indicating that he or she accepts the results of the election as valid; losers of close elections are often pressured to waive their right to a recount. Mandatory recounts are generally ordered when the margin of victory is extremely close. For example, a jurisdiction might mandate recounts when the margin is less than 0.05%, or when the difference is 2,000 votes or less.
In an optional recount, someone can specifically request that the ballots be counted again to verify election results. Someone who loses an election can request this, or a member of the general public can file a request. The person who asks for the recount must usually bear the costs, and in many cases, a deposit is required with a request, to confirm that the person is serious about questioning the election results.
People can ask for an optional recount if the margin of victory is very low, or if they suspect that voting irregularities have occurred. Irregularities can include things like voter intimidation, malfunctioning voting machines, lost ballot boxes, and so forth. Some nations use neutral election observers to monitor elections for signs of such irregularities so that they can be addressed as they occur or are reported.
When a government counts ballots again after an election, it has the option of doing it by machine or by hand. A machine recount typically takes less than a day, as the ballots simply need to be fed through the scanning machines used to read results again. In the case of electronic voting, the information at the polling stations is taken from the hard drives again, or any paper trail will be audited by machine to confirm the results. In a hand or manual recount, the ballots are personally examined in a process that can take weeks or even months.