It wouldn't be a trial without a few errors.

Not all digital driver’s licences were accepted by NSW Police during a four month trial of the technology in the regional city of Dubbo.

The fully electronic vehicle licence has been available to motorists from the central west region for use in police checks and gaining entry to pubs and clubs since November last year.

The NSW government is using the city as its testbed for a wider rollout of digital driver’s licences and digital photo cards across the state next year.

It passed legislation last month to enable the full rollout of digital licences on an opt-in basis, and earlier this week allocated $9.3 million for its efforts in the state budget.

The legislation requires that citizens produce either a digital or physical version of their driver licence when requested to do so by police or other law enforcement officers.

Police can verify digital licence using traditional means - such as several visual security features or by radioing back to a station for more information - or a MobiPol device, which scans the licence against backend police systems.

But answers to questions on notice published overnight reveal that police didn't always accept the digital licences during the first four-month phase of the trial.

Three separate surveys conducted by Woollcott Research found that of an average 14.6 percent of participants that had an opportunity to show their digital driver’s licence to police, it was rejected on 10 percent of occasions.

This was despite “several education sessions” with police “present[ing] the legal obligations of the trial and how the interaction of the DDL with the Police MobiPol device for licence searches and infringement processing”.

Lack of acceptance was one of several main concerns expressed by the 17 percent of participants that were dissatisfied during the trial.

The government is now preparing to conduct a second trial in a metropolitan area.