Police have mistakenly issued more than 20,000 traffic fines.
The traffic infringement notices for offences between October 22 and December 16 were issued to the wrong people after a data blunder.
The error occurred when NZ Transport Agency information about vehicle transactions for that period was mistakenly withheld from police due to a technical issue.
It means people who sold their cars in that period may have received fines meant for the new owners. Those who changed their address or surnames during the specified period could also be affected.
The fines are mainly speed camera infringements, with a smaller number of other camera-related notices including red light camera offences and police-issued parking notices. It does not affect council-issued parking fines.
Police say previous vehicle owners incorrectly ticketed won't have to pay their fines and anyone who has already paid will be refunded.
Police originally said there were 38,000 false fines, but later revised the number to 20,000 thanks to a separate mistake by police collating the data.
A member of the public alerted police to the problem after receiving a ticket for a car she did not own.
Police have said sorry for the error and say anyone who has paid will be refunded.
"Police apologise to all those people affected by this problem, including previous vehicle owners, as well as motor traders and dealers, who have understandably been fielding calls and complaints from concerned customers," said national road policing manager Superintendent Carey Griffiths.
The amounts involved could range from $30 to $630 but police say most are likely to be at the lower end of the scale. The total amount of incorrect fines issues is not known.
They say they have put a number of processes in place to ensure it does not happen again and advise anyone affected or who thinks they might be affected to go to the police website.