Louisiana is among 21 states seeking more than $150 million in uncashed money orders from Delaware, where more than 1 million businesses take advantage of friendly incorporation laws and unclaimed financial property is a major source of state revenue.

A lawsuit filed directly to the U.S. Supreme Court is another escalation in an ongoing dispute involving uncashed money orders from Dallas-based MoneyGram, which has been submitting unclaimed money to Delaware.

MoneyGram is incorporated in Delaware — just like more than half of all publicly traded companies in the U.S., and about two-thirds of the Fortune 500 companies. Delaware benefits significantly from rules that ultimately route unclaimed property to the company’s state of incorporation instead of the state of origin.

As a result, abandoned property is the third-largest source of general fund revenue for Delaware, and is expected to total more than half a billion dollars in the current fiscal year.

Other state officials contend the MoneyGram checks should be sent back to the state of purchase. Pennsylvania and Wisconsin have previously sued Delaware over the same issue, which the Supreme Court has yet to consider.

“We are committed to get this money for unclaimed MoneyGram checks reverted to the states, claiming what rightfully belongs to our taxpayers,” said Texas Attorney General Ken Paxton, who announced the lawsuit in Washington on behalf of the 21 states.

A Delaware official disputed the allegations and last week asked the Supreme Court to keep the status quo.

Other states in the lawsuit are Arkansas, Alabama, Arizona, Colorado, Florida, Idaho, Indiana, Kansas, Kentucky, Michigan, Montana, Nebraska, Nevada, North Dakota, Ohio, Oklahoma, South Carolina, Utah and West Virginia.

Under U.S. Supreme Court rulings, unclaimed property is reported to the state of the owner’s last known address appearing on a company’s records. But if the owner’s address is unknown or incomplete, the unclaimed property is reported to the company’s state of incorporation.