Ohio's tax department says it will start alerting businesses when they've overpaid taxes and help them reclaim their money.
Previously, if businesses failed to discover the error in paying their commercial activities tax within a certain time frame, they lost the right to reclaim it.
Gov. John Kasich and tax Commissioner Joe Testa announced the policy change Tuesday.
They said the Ohio Department of Taxation will begin notifying about 3,500 taxpayers who may have overpaid by a total of up to $13.7 million.
The commercial activities tax is Ohio's primary business tax. It generated $1.65 billion in the last budget year that ended in June.
The department also plans to review other taxes in an effort to reach out to all taxpayers who unknowingly paid too much.