Wellington City Council has apologised after it sent outstanding rates bills and corresponding addresses to the wrong households.
About 1400 people have been caught up in the "embarrassing" privacy breach.
Affected ratepayers were sent emails from the council this week outlining the error in the latest round of rates reminders issued on December 13.
When the reminders were being prepared, there was an error in merging the outstanding amounts and the contact details of the people those amounts related to, the email said.
"This resulted in the rates reminder email that you should have received being sent to another email address.