According to the NSW Electoral Commission, residents who were eligible to vote but didn't will be sent a 'Failure to Vote' notice in the mail. The notice calls for a reason as to why the recipient didn't vote or they must pay the penalty.

"You must respond within 28 days of the issue date of the notice," the Electoral Commission said.

"If you do not reply within 28 days, we will send you one reminder notice before referring the matter to Revenue NSW for further action.

"This may include a penalty notice enforcement order against you, and lead to the cancellation or suspension of your driver licence, or the cancellation of your car registration."

The notice must be responded to in writing with the reason the recipient did not vote, and not knowing the election is on is not considered a sufficient reason.

Fines can be paid online, via the phone, BPAY or a cheque or money order can be sent in the mail.

If recipients want to take the issue further, it can be disputed in court. The Electoral Commission says a court may impose a penalty for an offence of failing to vote of $110, plus the court costs.

Compulsory voting for state elections was introduced in 1915, while it wasn't made compulsory in federal elections until 1924.

As well as voting at a polling place on Saturday, residents could also early vote, use iVote online or telephone voting or submit a postal vote.

As of March 4, there were 56,939 electors enrolled to vote in the Orange electorate.