Many ridings were too close to call last night and finished with tight margins between candidates. That could result in recounts and delays in knowing who won in those ridings for days.

Contested or unclear election results can lead to recounts. According to the Canada Elections Act, there are three main ways results can be reviewed:

Automatic recounts occur when the vote difference between top candidates is 0.1 per cent or less. Elections Canada requests a judge to oversee the recount within four days.

A candidate may request a recount, even when the margin isn’t that close. But they have to request it within four days of validated results, file an affidavit alleging an error, and pay a $250 deposit. If approved by a judge, the recount starts within four days.

Both of those types are called judicial recounts and can only begin after official results are validated (which can take up to a week). Judges may count all ballots, just valid ones, or check a sample.

Contested results are more serious and rare. They involve claims of fraud, corruption, or candidate ineligibility. Anyone in the riding can file a challenge within 30 days ofallegedly discovering wrongdoing and the official results being published. A $1,000 deposit is required, and the case goes to Federal Court or a provincial superior court. These cases can take days or weeks.