The Vermont Department of Taxes says a computer glitch displayed personal information of more than 1,300 people and 245 businesses that were part of a weekly property tax data package.
The information was available to the public for less than two hours on Monday before the information was taken offline.
The social security numbers and the federal employer identification numbers of the businesses were involved.
State officials have contacted two of the three individuals known to have had access to the information when it was public and they have agreed to destroy the information. They are now working to identify the third person.
The tax department says all affected taxpayers will receive a letter saying their information was disclosed.
The state said Tuesday that the risk to the taxpayers is small.