The Department of Revenue must return $2.94 billion to taxpayers because state revenues blew past the allowable amount under a voter-approved law, Auditor Suzanne Bump confirmed Thursday.

In a report that shifts the spotlight back to the Baker administration and the Legislature, Bump certified that the 1986 tax cap law known as Chapter 62F set the maximum fiscal 2022 state tax revenue figure at $38,871,154,627. State government collected $41,812,654,358 in FY22, leading to an overage of $2,941,499,731, Bump said.

"According to Chapter 62F, a return of this amount in the form of a credit must be effectuated by the commissioner of DOR," Bump said.

The auditor said her review "requires us to do more than check DOR's math," and her team applied "generally accepted government auditing standards in our review to verify the accuracy and completeness of the report provided by DOR."

"This provides us with reasonable assurance required by those standards that DOR's figures are correct," Bump said.

Details about how the money will flow back to Bay Staters remain unclear. An administration official said this week the statute calls for excess revenue to be distributed on a proportional basis, meaning taxpayers with a higher income tax liability last year will receive a larger boost.

The auditor's report confirmed the estimates the administration produced and factored into a closeout supplemental budget Gov. Charlie Baker filed, which seeks to set aside $2.94 billion to be steered back to taxpayers.

Lawmakers have not touched that bill since it landed in the House Ways and Means Committee, and they have not made clear if they would revive a $4 billion economic development and tax relief bill they shelved amid confusion over the impact of 62F relief.