Popular Wellington bar Dakota has started implementing PatronScan technology after increased concerns about the city after dark.

The machines are designed to scan people's identification to check whether it is valid, to stop underage people entering the premises and to make nightclubs safer by holding data on those who cause issues.

Wellington Entertainment Group operations manager Cody Halton said the benefits of PatronScan are endless.

"Not only does it ensure that we aren't allowing underage people into the venue, but it holds people accountable to their actions."

Halton said they have had no issues at Dakota since installing the system.

He hoped other bars on Courtney Place would adopt the device so they could link them throughout the city.

This would mean nightclub security could see whether patrons had caused issues at other bars and decide whether to let them in or not.

It doesn't mean a venue would have to deny the incoming customer but it will alert them to the fact there has been an incident somewhere else, Halton said.

"I think this is a great positive to the system, having the threat of being banned from the whole of Wellington nightlife - be it for a weekend, week or month - would hopefully deter any wrongdoers from causing trouble."

Halton said they are advising people to always bring their IDs to the bar even if they are obviously over the age of 25 so they can keep a record of entry should anything happen at the bar.

However, if someone does want to get into the club without an ID there is a manual option.

Halton insisted there are no privacy issues with the software.

"The data that is captured is limited to name, date of birth, post code, gender and then a picture of the person. The picture is taken upon entry and is matched to the picture on the identification given to ensure that it is the correct person's ID."

He said data is permanently deleted after 30 days unless an incident had occurred, and an entry ban had been placed on an individual.

Anybody who has used PatronScan can request a copy of the information held on them by going to the software's website and making a request under their privacy page, Halton said.

Halton hoped the software will be seen as a great way to return to enjoying Wellington nightlife again without the stigma of it being unsafe.

University of Auckland Associate Professor Gehan Gunasekara said he's not concerned about the use of the technology itself but how data is held, who it is shared with and for what purpose.

"The Privacy Act requires that you are careful when using personal information to make sure it is accurate, up to date and not misleading, hence excluding someone where you have the wrong name/ID can have consequences."

Gunasekara said other laws than privacy may also apply for example if certain groups are treated differently to others this could amount to discrimination.

Rules need to be consistent and predictable, he said.

Wellington Entertainment Group plans to install PatronScan technology at bars The Establishment and The Residence in the next two weeks.

Wellington's nightlife has been under the spotlight in recent months due to concerns around safety, particularly sexual assault and harassment.

In March, hundreds of people attended the #LetUsLive rally on Courtenay Place, calling for a city free from sexual violence.