The NSW-Victoria border is shutting from midnight tomorrow, and getting through the blockade will depend on what you do and where you live.

NSW Premier Gladys Berejiklian described stopping travel between Australia’s two most populous states as a “mammoth task”.

It effectively means more than 50 road crossings, as well as train stations and airports will need to be patrolled.

This is what you need to know about the closure.

How will it work and who will enforce the rules?

Officials will strictly monitor 55 ground crossings — including four major highways, 33 bridges, two waterways with police and health officials on standby to question travellers returning via air or rail.

It is expected to reflect what Queensland implemented more than three months ago which prevented inbound traffic to Queensland while New South Wales remained open with officials monitoring passengers at airports and train stations.

Only permit holders, emergency services workers, freight drivers and returning travellers will be able to cross into New South Wales from Victoria.

NSW and Victoria share at least 50 border crossings. (ABC News)

Ms Berejiklian said it was an “unprecedented” move but the timing was critical.

“We’ve already been in contact with a number of border communities to explain to them that whilst the next 72 hours will be difficult … permits will be available, exemptions available and Service New South Wales will be able to do that online and make it as easy as possible.”

“What is occurring in Victoria has not occurred anywhere else in Australia — it is a new part of the pandemic and as such it requires a new type of response.”

Anyone returning home to New South Wales will be required to self-isolate for 14 days.

While Ms Berejiklian described the closure as “temporary”, there is no timeframe for it to reopen — something particularly concerning for people in the border communities that may travel between the two states several times each day.

“I don’t want to see this happen for a long time, I want to see this happen in as short a time as possible,” she said.

“The numbers today are concerning because it shows the replication factor [is] increasing in terms of how many are passing the virus on to others.

“Until that dies down, I don’t think the border closure will change.”

How do I apply for a border permit?

From 12:01am on Wednesday, people wanting to travel from Victoria to NSW will need to get permission from the State Government.

Permits are likely to be divided into two categories: one for people who live in border communities like Albury-Wodonga, and another for anyone who believes they need to cross the state line for “exceptional circumstances”.

In other states, travel exemptions have been issued for people who need to care for sick relatives.

Ms Berejiklian said anyone who is given an exemption to travel to NSW will have to self-isolate for 14 days.

NSW Police Commissioner Mick Fuller said people caught lying on a permit application would be fined.

What if I live near the border?

People in border communities will be able to cross the border for work, or to receive essential health services — but they will still need a permit.

Wodonga Mayor Anna Speedie said she hoped for a smooth process.(ABC News)

Ms Berejiklian said people who lived in places like Albury-Wodonga, which straddle the state line, would be able to move between NSW and Victoria more freely, but conceded they would likely find the closure frustrating.

Wodonga Mayor Anna Speedie said she hoped the permit system would be implemented quickly and without complication.

“While we’ve got two separate cities in two different states, our cities absolutely act as one economy and one community,” she said.

“About half of my people work in Albury and about half of Albury work over here so it’s going to be incredibly challenging.

“I’m really hoping that permit system is sensible.”

Is there a penalty for crossing the border?

Commissioner Mick Fuller said as well as roads, there would be monitoring of entry points accessible by swimming or walking.

Drones and other aerial surveillance measures will be used, on top of the policing of the four main arterial roads.

The penalties for infringements remain an $11,000 fine and six months in jail.

He said it was seeking new health orders for the power to turn people around.

“We’ll be focussing no doubt on the four primary arterial roads because we know that’s where most of the traffic comes,” he said.

“But nevertheless there’ll be police and defence and other emergency services workers across a majority of those crossings and there will be aerial and other surveillance 24-7 right across that border.”