In a two-day operation, 28 outlets were tested by underage volunteers aged 17 who tried to buy alcohol.
Two sales resultedin the Hokianga and Kaipara areas.
Police alcohol harm prevention officer for Kerikeri Michelle Row said 10 premises were tested in the Hokianga district and despite an improvement since the last operation, “one sale is too many”.
“It is expected all outlets should have good systems and processes for checking for underage, especially when operating in our vulnerable communities.
“As a community, we need to have confidence that license holders will not sell alcohol to our youth.”
Of 18 premises tested in Kaipara, one sale took place.
Sergeant Tai Patrick said applicants with licenses to sell alcohol should have the appropriate systems and procedures in place to prevent the sale of alcohol to those underage.