"Advance voting has been growing in popularity so we did expect to see an increase, but we also did encourage people to vote early to help spread out voting across the period because of Covid-19, to reduce queues in voting places."
She said it was too early to say whether the number of advanced voters would contribute to an overall higher voter turnout.
"We will not know turnout until late tonight. We will have an estimate."
The spokeswoman said voting today had been steady across the 2567 voting booths around New Zealand.
Counting of the advanced votes began at 9am today, giving the Electoral Commission a head-start on results, which won't be announced until after the polls close.
Today's voting centres close at 7pm when the rest of the counting will take place and preliminary results are expected soon after.
Due to electoral rules the Herald is prevented from reporting any political stories that could influence voters on election day until 7pm today.
Political coverage and results will resume on the Herald website after that.