Some bar managers say they are expecting chaos when new alcohol laws come into full effect on Wednesday.
Under the Sale and Supply of Alcohol Act that was passed last year, bars will have to close earlier and licensed premises will face harsher fines if they serve minors or intoxicated punters.
One bar manager on Auckland's viaduct says the new morning closing time of 4am will create carnage on the streets, when everyone leaves bars at the same time.
He says bars are going to lose a lot of money with the laws coming in just before Christmas,
when they make the most revenue.
Hospitality New Zealand says it is not in favour of all the provisions of the Act, and says time will tell whether it will help reduce alcohol-related harm.
A Hospitality New Zealand spokesperson, Nadine Melhopt says there is some anxiety around the new rules, but not with all members.
"We have a lot of members who are concerned there will be a significant decrease in trade, and then we have other members who are saying that 4am is around about when they close anyway."
Melhopt says another concern is that some premises are facing a $3,700 fee increase for a three-year license.
Other changes in the Act include fines of up to $10,000 for bars if they are caught serving an intoxicated person.