Tax officials in the US state of Utah on Thursday announced that same-sex couples married in the state, or elsewhere, were allowed to file joint tax returns.

The Utah State Tax Commission made the announcement today, which affects 2013 state tax returns.

“Same-sex couples whose marriages were performed in Utah pursuant to the federal district court’s order between Dec. 20, 2013, and Dec. 31, 2013, or whose marriages were solemnized in other states before Dec. 31, 2013, may file individual State income returns as ‘married,’” Charlie Roberts, spokesperson for the Tax Commission said.

The Commission previously said it would not allow same-sex married couples to file their returns together. It has not explained its reversal.

Between 20 December and 6 January, some 1,300 couples married in the state as a US District Judge ruled that a ban on same-sex marriage violated the state’s constitution.

The US Supreme Court last Monday put a stay on equal marriage in the US state of Utah, forbidding same-sex couples from being issued with marriage licences in the state during an appeal against a ruling to allow them.

The Utah Attorney General Sean Reyes advised Governor Gary Herbert that marriages between gay couples who married in that short period should not be recognised by the state for benefits purposes.

US Attorney General Eric Holder has since responded to calls to say Utah married same-sex couples would be treated as married by the federal government, despite a directive from the state Governor that they would not.