Wellington ratepayers will pay $20,000 to get early-morning revellers home safely as the city prepares for the "early morning rush-hour" when bars start closing at 4am.

From December 18, when new default liquor laws come into effect, bars throughout the country will not be allowed to stay open beyond 4am.

At the moment about 30 bars in Wellington are licensed to stay open past 4am.

In preparation for the change - and in anticipation of crowds filling the streets when bars close simultaneously - Wellington City Council is spending about $20,000 to make the transition run smoothly for the first weekend from December 20 to December 22.

Among measures being planned are extra buses at 5am, with security guards, a triage centre run by Wellington Free Ambulance, and extra taxi stands.

Council spokesman Richard MacLean said there was going to be an "early morning rush-hour", and the city had to be prepared, especially as many bar-goers might be unaware of the earlier closing.

"We're going to be giving the bars a lot of resources and giving them a hand to try and explain it to the hopefully not-too-befuddled patrons."

Making sure there were options for people to get home was a priority, he said.

He expected a lot of taxis to target Courtenay Place about 4.30am, and extra bus services would also be provided.

"We want to have a few resources out there and make sure people get home OK."

At present, most late-night buses stopped about 3am, but services for Johnsonville, Tawa and Porirua, Upper Hutt and Lower Hutt, Wainuiomata and Eastbourne will be available at 5am.

The measures will be in place for only the first weekend, which is also the last before Christmas and traditionally a busy one for bars.

After that, the situation would be assessed with key groups, including police, to see if the measures needed to continue until the council's local alcohol policy, adopting different hours, was implemented, Mr MacLean said.

Wellington City Council adopted its policy this year, setting a 5am closing. However, due to notification and appeal periods, it is unlikely to be introduced until late next year.

At hearings earlier this year, health officials called for tougher limits on the availability of alcohol, and on bars and retailers.

"The earlier that there's [bar] closure, reduction of alcohol, the better," said Paul Quigley, emergency medicine specialist for Capital & Coast District Health Board.

Late at night at weekends up to 72 per cent of hospital admissions were related to alcohol, Dr Quigley said.

However, alcohol retailers described the earlier-closure plans as "tinkering" that would not solve problems.