Thanks for your question, Alex.
The counting of votes in Parliament happens during divisions—formal votes of members or senators. When a division is called, members or senators usually have 4 minutes to be in position and ready to be counted.
In the Senate, the tellers stand next to the Clerks’ desk and call the names of the senators voting on each side. The names are marked off by the Clerks on printed division lists. When the lists tally—agree—they are signed by the tellers and the Clerks. The Clerk then passes the lists to the President (or their deputy) to announce the result.
The House of Representatives recently moved to recording the results of divisions electronically. The tellers use tablets and mark off the names of the members. This means that any potential error—such as a member being recorded as voting both ‘yes’ and ‘no’—is caught immediately. It also means that the results can be published online very quickly.
Occasionally, counting errors that don’t affect the result are made. These are usually caused by pairing—agreement between whips that some members or senators won’t vote in a division. These errors are corrected and then signed by the tellers.
If there is a mistake or confusion over the division result, and it cannot be easily corrected, the Standing Orders—rules of the House of Representatives and the Senate—allow for another division to be held.