Bars like Fat Eddie's in Christchurch are introducing ID scanners, which has raised privacy concerns.

Causing drunken chaos in Australia could see you banned from your favourite New Zealand pubs, thanks to ID scanning technology.

Patronscan, a company that sells machines used to scan IDs at bars and nightclubs, can share data about patrons who have caused trouble at venues across the Tasman. The scanners record a person's name and age and take their photo.

Those given lifetime bans on the system have their details stored forever. Data for customers who behave is deleted after 30 days.

The service is used widely in Australia and it estimated there are about 20 scanners in use in New Zealand.

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CHRIS SKELTON/STUFF Stuff reporter Steven Walton hands over their ID to be tested by the Patronscan system.

Patronscan's Australian technical manager Michael Giannak said data was passed between Australia and New Zealand, but there was no worldwide information sharing.

Only authorised management staff had access to the data, he said.

CHRIS SKELTON/STUFF This shows the operating system of Patronscan as it scans Steven Walton's details.

Popular Christchurch bar Fat Eddie's uses the software on all people judged to be under 25. It is managed by Security company October Protection and only in place on Friday and Saturday nights.

Security staff there would be alerted if a person banned from an Australian pub using Patronscan tried to enter.

October Protection chief executive Matt Wood said his firm and Patronscan were the only ones with access to the data.

The system was also used for tracking the number of people in the venue and demographics.

Benefits included detecting fake IDs and alerting security staff to people who have already been banned, Wood said.

JOSEPH JOHNSON/stuff Fat Eddie's in Christchurch uses an ID scanner on Friday and Saturday night. This photo is from the opening of the nightclub in 2017.

"It's not out there for big brother watching you ... it helps to stop criminals from coming in," he said.

Patrons generally behaved better because they did not want to risk getting banned, Wood said.

Only two lengthy bans had been issued in the past two years – one for two years and one for six months.

When Patronscan first started appearing in New Zealand in 2012, the Office of the Privacy Commissioner raised concerns.

CHRIS SKELTON/STUFF Matt Wood, chief executive of October Protection, says Patronscan can detect fake IDs.

This week, a spokesman questioned whether bar staff were informing people of their rights during the scanning process.

October Protection demonstrated the system for Stuff and pointed out a privacy warning attached to the front of the scanner. It does not state who can access the information, but does have Patronscan branding.

Wood agreed it was a "natural reaction" for people to be concerned about having their ID scanned, "especially in what's perceived to be a very safe country as New Zealand".

STEVEN WALTON/STUFF This is the privacy sign attached to the front of the ID scanner at Fat Eddie's in Christchurch.

Caroline, who declined to give her last name, said the scanning of her ID at Fat Eddie's felt "weird".

The door host did not appear to know where the data was going but told her it was safe, she said.

"These days people are aware of data-sharing therefore if someone's taking your data, they should be at least be able to tell you what's happening to it."

Wood said all people had to know was that their data was stored safely.

"We're trying to scan through in excess of 1000 people, we haven't got time to be answering a million questions," he said.

Anyone with concerns could contact him for further details, he said.

Jeremy Smith, managing director of the Trinity Group, which owns multiple hospitality outlets in Wellington, previously trialled Patronscan ID scanners.

Individuals had raised some privacy concerns during the trial, but this was not the main reason for his decision to stop using the technology.