South Korea's win over Lone Star on the tax issues of an investor-state dispute settlement case is now binding, with no remaining avenues for appeal.

The National Tax Service announced the move in an explanatory document on Monday, outlining the tax implications of the Lone Star ruling.

The tax component of the case concerns whether the South Korean government has the authority to impose taxes on the U.S. private equity firm, which, on paper, is based in a tax haven.

While Seoul won the tax portion of the initial ruling by the International Centre for Settlement of Investment Disputes(ICSID) in 2022, the decision was confirmed in the annulment suit.

In 2012, Lone Star sued South Korea for four-point-68 billion U.S. dollars in damages, claiming the government's delayed approval had torched the planned sale of its stake in the now-defunct Korea Exchange Bank to HSBC in 2007.

The firm also accused the state tax agency of arbitrary and contradictory taxation—one-point-47 billion dollars of its total claim pertained to this matter.

Last week, the ICSID annulled a 2022 ruling ordering Seoul to pay 216-point-five million dollars in principal and interest to Lone Star.