Thousands of Maryland residents will be receiving a hefty check in the mail after a historic Supreme Court ruling earlier this month.

According to WTOP.com, Gov. Larry Hogan announced that over $200 million will be reimbursed to an estimated 55,000 people in Maryland as the result of a Supreme Court decision that found a flaw in the state’s out-of-state income tax regulations.

The ruling comes after residents Brian and Karen Wynne took the state to court after receiving an exorbitant income tax bill.

The Howard County couple paid $84,550 in income taxes to 39 other states, but the state ruled that they could not deduct the money they had already paid towards their Maryland taxes.

According to the Baltimore Sun, the Wynnes sued on the grounds of illegal double taxation after they learned they they did not get a credit for what is called the “piggyback” income tax, in which the state collects on behalf of local governments.

While Maryland had the rule in place to only affect affluent citizens with investments in multiple states, Wynne said he only had partial ownership in a healthcare company that does business out-of-state.

The Wynnes won his case in a 5-4 Supreme Court ruling.

The landmark ruling is sure to send a ripple effect through other states that collect income tax. Florida, Alaska, Nevada, South Dakota, Texas, Washington and Wyoming are the only seven states that don’t collect an individual income tax at the state level.

“This is money which was wrongfully taken from the taxpayers of the state when they were overcharged for their income taxes,” Gov. Hogan said. “Many of these taxpayers don’t even know that they were overcharged, and do not know that they’re entitled to this refund.”

The refund will only apply to Maryland residents who paid out-of-state income tax from 2011 to 2014.

The governor is urging those who believe they are eligible for a refund to visit www.WynneTaxRefund.Maryland.gov to learn how they can receive their reimbursement.