The Electoral Commission says it does not believe candidates leaving political billboards out on election day are intentionally trying to influence voters.
The commission says it has received a handful of complaints about billboards still up after a ban on them came in at midnight on Friday.
No material designed to influence voters is allowed on election day.
The commission believes forgetting to take down the hoardings is generally an oversight rather than deliberate.
On Saturday, the Electoral Commission asked the Scoop website to change a graphic that appeared to call the result of the election but said because the website made the change it was not taking any further action.
Electoral rules restrict news media from publishing material likely to influence voters.
National Party leader John Key says keeping election day free of campaigning on social media is challenging and probably needs to be looked at.
Mr Key said internet media and social networking sites, some of which he says are quite influential, have to obey the same rules as standard media outlets.
He said it would be unfair to give internet and social media and advantage over traditional forms of media.