Hospitality New Zealand says new alcohol laws will be put to the test as hundreds of people are expected to be ejected from bars and clubs around the country at 4am on New Year's Day.
Under the Sale and Supply of Alcohol Act passed in 2012, bars will have to close earlier and licensed premises will face harsher fines if they serve minors or intoxicated people.
Hospitality New Zealand's national president Adam Cunningham said there would be many people out on the streets suddenly when bars have to close.
"It will mean unlike perhaps a normal weekend revelry, where people may progressively fade off as the night goes on, New Year's is a big one. So we will see an influx of people out onto the streets at 4am.
"There is no bar in the country that won't be in a position that they have to shut up shop - it's a legal requirement."
Mr Cunningham said he hoped police have the correct resources to deal with any trouble that might happen when bars start to close.
ACC supports app
ACC hopes a new smart phone application will help reduce the number of alcohol-related injuries on New Year's Eve.
The 'DrinkSmart' app measures extra calories consumed from alcohol and how much is being spent on a night out.
ACC supported the development of the software because it estimates alcohol is a factor in almost 11% of injuries it deals with each year.
Spokesperson Glenn Donovan says the aim of the app is to support people to make informed decisions about their drinking and ACC is keen to hear from people who have used it.